Agricultural Drainage

B E S T M A N A G E M E N T P R A C T I C E S � B M P s F O R C R O P L A N D E R O S I O N C O N T R O L 9 7

BMPS FOR CROPLAND EROSION
CONTROL

Properly designed and located erosion control structures can safely convey excess
water to an appropriate outlet. This chapter explains how to verify soil erosion 5.01p
issues, presents different types of erosion control structures and their respective
features and maintenance needs, and shows how to plan for their implementation.

Some surface drainage structures are intended to remove ponded water
from depressional areas on cropland. However, not all surface water
is ponded. In fact, ponded water can become runoff if permitted to
overflow into low runs (draws) in unevenly sloped fields.
On sloping cropland, runoff can lead to the erosion of soil particles.
Cropland erosion in uniform layers is known as sheet erosion. Erosion
caused by concentrated flow forms rills. When the rills develop into
channels large enough to prevent crossing by farm machinery, these
channels are known as gullies.
Subsurface
drainage systems
VERIFyING EROSION PROBLEMS remove excess
gravitational waters
– making room for
Highly erodible soils can be predicted based on practical experience. Erosion can be verified
precipitation and
on-site by looking for:
runoff to infiltrate
� eroded knolls (”white-caps”) and shoulder cropland soils.
slopes (usually the result of tillage erosion) In this regard,
5.02p cropland drainage
� washouts (rills) systems are an
integral component
� aprons of topsoil in depressional areas after a
of soil and water
storm event conservation
� off-site (or on-site) movement of runoff and systems.
sediment.
In a field with a 5% slope and loamy soils, the
rate of soil loss and runoff would be even greater
if there were small pathways for water to run Soil erosion problems are more noticeable if
downhill. Unchecked, these small pathways can soils are left bare.
lead to rills and gullies.
No-till is effective in controlling sheet erosion. However, when no-till is practised on
complex slopes, rill erosion can be a serious problem. The remedy is to use erosion control
structures to capture surface water and deliver it to the subsurface drainage system.

9 8 B E S T M A N A G E M E N T P R A C T I C E S � A G R I C U L T U R A L D R A I N A G E

EROSION CONTROL STRUCTURES

Erosion control structures are designed to both control erosion and safely convey surface
5.03p water to an adequate outlet. Common examples include grassed waterways, terraces, and
water and sediment control basins (WaSCoBs). Some of these systems are designed so that
the rate of water removal has been reduced.
Calibrated standpipe inlets (e.g., Hickenbottom inlets) in WaSCoBs limit sediment loading
from runoff events by allowing the water to pond for a short period of time and soil particles
to settle out before entering the inlet.
Erosion control structures move surface runoff to subsurface drainage systems and, by
strategic placement, limit the erosive forces of runoff events. This type of erosion control
structure includes diversion terraces and narrow-based terraces.

A systems approach is the most effective way to
address cropland runoff and erosion problems. A soil and
water conservation system designed to reduce the risks
of soil loss has the following components:

• cropland erosion control structures
• surface water management
• subsurface drainage
• soil management BMPs, and
• conservation tillage and cropping practices.
Erosion control
structures are
designed and
constructed to convey
overland flow to a 5.04p 5.05p
safe outlet.

4 WaSCoBs are earthen embankments across 4 Grassed waterways are graded and grassed
draws, with retention basins and calibrated riser channels placed in draws with subsurface
pipe inlets (drop-pipe inlets) to convey water drainpipe, intended to divert and transfer
to an adequate pipe outlet. These structures runoff to a properly protected outlet. They work
reduce erosion downslope. The duration of best when established as part of an erosion
temporary ponding is carefully engineered to control system that includes soil conservation
reduce the risk of damaging the crop. Inspect BMPs such as no-till and mulch tillage.
after major storm events and ensure that the
inlet pipe is not blocked by sediment or crop
debris.

B E S T M A N A G E M E N T P R A C T I C E S � B M P s F O R C R O P L A N D E R O S I O N C O N T R O L 9 9

5.06p

4 A diversion is a combination of channels and berms placed across slopes (reducing the
grade) to slow down the runoff and reduce erosion. The water is conveyed to a grassed
waterway or to a surface inlet where the water is then carried via an underground
drainpipe to a proper outlet.

4 A large-diameter pipe (drop
pipe) is installed to convey
5.07p
water down steep slopes or
high drops to prevent ponded
water or concentrated flow
from forming large rills or
gullies.

1 0 0 B E S T M A N A G E M E N T P R A C T I C E S � A G R I C U L T U R A L D R A I N A G E

5.08p

4 A rock chute spillway is a constructed chute using angular stone (riprap) and underlain with filter
cloth. Rock chutes are often placed in riparian areas to convey concentrated surface flows safely to
watercourses. As with all erosion control structures, rock chute spillways are most effective when
managed as part of a soil conservation system.

B E S T M A N A G E M E N T P R A C T I C E S � B M P s F O R C R O P L A N D E R O S I O N C O N T R O L 1 0 1

EROSION CONTROL STRUCTURES

BMP + DESCRIPTION FUNCTION & DESIGN FEATURES MAINTENANCE & REPAIR

TERRACE • intercepts surface runoff and breaks up a single • monitor in spring and after storm events for
slope-length into shorter lengths breaches in, or erosion of, berms
Earthen berm or ridge • constructed at a suitable lateral grade to an outlet • ensure proper functioning of emergency
across slope • see WASCoB for design considerations spillway
• keep drop-pipe inlets clear of debris

WaSCoB • berm and basin with inlet built across slope to • monitor inlet area for function and condition
divert runoff to subsurface drainpipe • clean debris from inlet to allow for proper
(Water and sediment • settles out some sediment functioning
control basin) • design accounts for watershed size and shape, rate • ensure the integrity of the berm
of runoff, volume of storage, erodibility of soil • keep track of soil sediment buildup and
Small water-detention material, and impacts of cropping and tillage remove when necessary
basins and berm practices on runoff
• works on watersheds up to 20 ha (50 ac)
• basin design is usually sized to hold 15 years of
eroded soil

DIVERSION • constructed across slope to divert water and runoff • monitor in spring and after storm events for
to a position where it can be safely conveyed breaches in, or erosion of, berms
A channel with a • see WASCoB for design considerations • monitor inlet area for function and
supporting ridge on condition
the lower side • clean debris from inlet to allow for proper
functioning

GRASSED WATERWAY • safe transport of runoff from field or erosion control • seed with recommended grass mixture and
structure such as diversions, terrace and fertilize to ensure proper cover
Natural or constructed, strip-cropping to a proper outlet • mow vegetation at least twice per year to
grassed waterway – • works best if part of soil conservation system promote establishment and cover
usually in draw or • has parabolic or trapezoidal cross-sectional shape to • reduce traffic on grassed waterway
between convergent resemble natural channels • don’t create dead furrow along water way
slopes • requires a subsurface pipe underneath to handle – could cause rill beside waterway
low-flow conditions and maintain good hydrologic • respect separation distances to keep
conditions cropland herbicides away from cover
• best suited to grades <5% • can be grazed or hayed if conditions are dry

DROP-PIPE INLET • intercept and carry a concentrated flow of water • monitor pipes and inlet area for function
safely from a higher to a lower elevation and condition
Enclosed vertical pipe • structures of steel, plastic or concrete vertical pipe • clean debris from inlet to allow for proper
structure connected to are usually located near watercourses functioning
subsurface drainpipe • can be used if drop is greater than 1.5 m (5 ft) • replace broken pipe, grates, and constrictors
• design based on peak flow, fall and distance, berm

size and spillway requirements

ROCK CHUTE SPILLWAY • safely conveys fast-flowing channelized water down • monitor for erosion under spillway, shifting
a steep gradient rocks and debris
• works well where water from a grassed waterway • remove debris
enters a drainage channel or stream or in old fence • replace and adjust rocks and filter cloth as
lines where the rate of water flow prevents vegetation needed to prevent scouring
from maintaining cover
• uses entrance and exit aprons to reduce erosion and
to control flow
• large rocks (22 kg (50 lb) are recommended
• anchored filter cloth underneath rock is recommended


PLANNING FOR EROSION CONTROL STRUCTURES

4 Seek technical advice for design and construction from professionals and trained
contractors.
4 Consider the following factors in the planning process:
� future land use – whether the land will remain in its current land use
� slope steepness, slope length, soil type, upslope (in-ﬁeld) watershed size – must
be considered when designing structures for size and safety
� cropping and tillage practices – how compatible a particular structure would be for
current crop types, field operations
� cost of options – which option provides the most value for the investment required
� potential improvements or changes to downstream water system.
4 To manage concentrated flow and reduce potential risks, you could:
� protect the draw
� reduce the length of eroding section by segmenting into smaller units
� divert the flow below the surface.
In fact, most erosion control structures are designed to attain one or more of these
objectives. For example, WaSCoBs reduce the length of eroding section and divert the flow
below the surface. Multiple units can be installed.

For more on cropland conservation structures,
see the BMP book, Field Crop Production. 5.09p

For more information please see OMAFRA
Publication 832: Agricultural Erosion Control
Structures – A Design and Construction Manual.

B E S T M A N A G E M E N T P R A C T I C E S � B M P s F O R S U B S U R F A C E D R A I N A G E 1 0 3

BMPs FOR SUBSURFACE
DRAINAGE

This extensive chapter begins with approaches to identify subsurface drainage issues. Accurate on-site
diagnostics are the first step in planning a subsurface drainage system. Once site conditions are
understood, system design is the next stage, and we will take it step by step. We’ll explain BMPs for
installation – using checklists for both landowners and licensed drainage contractors. As we move to
maintenance and management BMPs, we focus on troubleshooting. The chapter concludes with a look at
emerging technologies.

The main challenges for subsurface drainage are:
• managing crop inputs and other contaminants
• removing excess water but also conserving water
• managing wet areas, and
• protecting adjacent wetlands.

Diagnosing Subsurface Drainage Issues
Conditions That Require Subsurface Drainage

In many cases, cropland drainage systems are established or improved due to the limitations
of local soil and site conditions. Also, we have a humid climate in Ontario, which means
that on average there is a net surplus of water on most croplands. The growing season
(optimum temperatures) is limited and soil needs to be in a good hydrological condition for
the full growing season.
Soils may need subsurface drainage for one or more of the following reasons.
Uneven soil moisture conditions. Soil moisture conditions are not sufficiently uniform for
efficient field operations on fields with highly variable soil types and slope positions.
Inadequate natural drainage for the crop’s sensitivity. Some crops are very sensitive
to water (“wet feet”), and are easily damaged if roots are in saturated soil. Some soils have
average natural drainage, but are unsuitable for the crop’s needs.
Soils with naturally high water tables. Usually found in level-to-depressional
topography or where impermeable subsoils limit water infiltration, these soils will benefit
from systematic subsurface drainage systems. Such soils are referred to as poor and
imperfectly drained soil types on soil maps and reports.

1 0 4 B E S T M A N A G E M E N T P R A C T I C E S � A gricultural D R A I N A G E

Fig. 6A

Soils may need subsurface drainage for one or more of the following reasons.
Uneven soil moisture conditions. Soil moisture conditions are not sufficiently uniform for
efficient field operations on fields with highly variable soil types and slope positions.
Inadequate natural drainage for the crop’s sensitivity. Some crops are very sensitive to
water (“wet feet”), and are easily damaged if roots are in saturated soil. Some soils have
average natural drainage, but are unsuitable for the crop’s needs.
Soils with naturally high water tables. Usually found in level-to-depressional topography or
where impermeable subsoils limit water infiltration, these soils will benefit from systematic
subsurface drainage systems. Such soils are referred to as poor and imperfectly drained soil
types on soil maps and reports.

Fig. 6b
Croplands soils with a
drainage class of poor
require subsurface
drainage. Poorly
drained soils have a
high water table for
most of the year. To
verify poor drainage,
check for a zone of
mottles and gley
colours in the top 50
cm (20 in.) of the soil
profile.


Water won’t flow to outlet because land is too flat or natural surface barriers limit movement
of water. Such sites are often in depressional areas.
Artificial barriers. Constructed barriers that obstruct or limit the flow of water include roads,
fence rows, dams, dikes, bridges, and culverts of insufficient capacity and depth.
Topographic site position. For want of sufficient land slope, or due to natural surface
barriers, water cannot flow to an oulet. Such sites are often in depressional areas.
Seepage areas. When water table conditions cause groundwater to be discharged on a
sloping field, the soil can be sufficiently saturated to require subsurface drainage. A single
seepage area can render a large area of cropland unfit for crop production.

Fig. 6c

Impermeable soil materials. Soil layers of low permeability that restrict the downward
movement of water trapped in small surface depressions or held in the soil profile may
benefit from subsurface drainage.


FIG. 6D

6.01p

In some cases, subsurface drainpipes are surrounded by impermeable
soils such as heavy clay, pure silts, or compacted subsoils.

Recharge areas do not
require subsurface
drainage.


Draining Natural Temporarily Ponded Areas on Cropland: A Matter of Need or
Convenience?

Removal of surface water from croplands has many potential benefits. On the other hand, these temporarily
inundated locations, although not permanent wetlands, may provide the water storage functions and habitat
for a variety of plant and wildlife species. Think carefully before you act in these situations.

4 Seriously consider the pros and cons of draining wet areas on cropland.
Questions to consider before draining a wet area:

• What is the size of the wet area?
• How is this area impacting nearby field operations?
• How long does the water stand on the surface?
• On average, how many days does this wet area delay field work in spring?
• On average, how often does this wet area contribute to crop flooding and significant profit loss?
• Does wildlife use this wet area when ponded or at other times during the year?
• Is there wetland vegetation present?
• Is this area immediately adjacent to a designated wetland or riparian area?
• Will this area grow a profitable crop when drained?
• Is a permit required from the Conservation Authority or other agency?
• Is the area a candidate for retiring from production?
• What will the drainage project cost?

By answering each of these questions, you’ll be in a stronger position to assess the significance of this wet
area and its relative importance and potential as cropland.

Visual Identification of Cropland Drainage Problems

Most naturally well-drained cropland soils in Ontario experience a moisture surplus from
November to April. These same soils are able to store moisture during the spring and early
summer. From mid-summer to early fall, this stored water is depleted – mostly through
evapotranspiration.
The amount of surplus water on imperfectly to poorly drained soil is substantially higher.


FIG. 6E

FIG. 6F
In April and May, the water table is too
high on imperfectly drained and poorly
drained soils for seedbed preparation.
These soils would benefit from
subsurface drainage.

6.02p
Indicators of poor drainage may include:
• uneven crop growth
• water at or near the surface
• water-tolerant vegetation
• soil colours indicating a high water table
• soil colours indicating uneven or long drying period.


It’s prudent to conduct a site investigation of drainage problems before drainpipes are
installed or in drained fields requiring troubleshooting. Simply put: cropland drainage
improvement is limited by site conditions.
There are two major soil-water-related problems in most fields: surface water soils and
groundwater soils.
Surface water problems occur where precipitation and snowmelt water on
the surface won’t infiltrate and percolate through the soil quickly enough for
agricultural use – resulting in soils remaining saturated too long. This can be due 6.03p
to high water tables, or soils that are impermeable, such as soils with a high clay
content.
Groundwater soils receive groundwater from upslope and are said to be subject to
artesian pressure. The nature and severity of the problem is mostly centred on
how water is discharged at or near the soil surface as well as the artesian (head)
pressure.

FIG. 6G

Slope

Seepage water
from upslope side
of check pit

Locating Drainage Problems in the Soil Proﬁle
Drainage problems can be found in four places in the soil: at the surface, in the plough
layer, in the subsoil, and around the drain itself.


Fig. 6H

Fig. 6I

Surface Problems
Most surface problems are associated with soil crusting – a sheet of soil that prevents infiltration.
Following the rapid wetting and drying of an overworked seedbed, a solid sheet forms (0.2–5 cm or 0.8–2
in. thick) that is tight enough to prevent crop emergence. A track record of poor soil management and
few organic matter inputs is most often the cause. A similar impeding layer at the surface can result
from “puddling” caused by a heavy rainfall of large rain droplets. Here the surface is compacted by the
droplets, creating a barrier.

4 dopt farming practices that maintain good soil structure and organic matter/crop residue to prevent
A
crusting.


Fig. 6J

Plough-Layer Problems
Most plough-layer drainage problems are actually compaction problems. Compaction is the process of
increasing soil density by packing soil or smearing particles closer together. It can occur anywhere in the
soil profile, but tends to be seen near the surface or at plough depth.

4 onsider a range of BMPs, including tillage at proper soil moisture conditions, use of deep-rooted
C
crops, and mulch tillage, to reduce the impact of compaction on soil structure.


Fig. 6K

Subsoil Problems
Subsoils can be impermeable and cause surface drainage problems. Impermeable subsoils are usually:
• heavy clays – soils with high clay contents and low natural permeability
• assive soils – clay, usually poorly drained soils, with massive structure where there are few connected
m
macropores to aid drainage
• compacted soils – some glacial till soils were smeared and compacted during deposition
more common near the Canadian Shield.
Other soils have naturally high water tables, and so cannot store additional water.
4 Have the problem properly evaluated by a licensed drainage contractor to determine course of action.


FIG. 6L

Around the Drainpipe
When water can neither permeate the soil around the drainpipe nor enter the drainpipe, it’s known as
entrance resistance. This can artificially elevate the water table. Saturated soils are prone to smearing by
drainage equipment. Look for gley colours and mottles around the drainpipe.

4 Don’t install subsurface drainage in saturated soils.
Soil Investigation to Verify Subsurface Drainage Problems
Soil investigations are the only sure way of verifying soil drainage problems. Two types of
soil investigation checks are recommended.
Soil Pit Method
A soil pit investigation allows the professional to look for changes in soil
colour and properties in soil horizons (layers).
Auger Hole Method
6.04p
A Dutch soil auger can be used to quickly check soil features in a core of soil
to depth of at least 1.2 m (4 ft).


Fig. 6M

Fig. 6N

0 cm

Ah

Bm

Aegj

B+gj

Ckg

120 cm


Fig. 6O In some soils, mottles and in
some cases gley colours are
found in an upper soil horizon –
Ap Loamy 10 yr 3/3 but not below. When combined
fine sand platy with a drastic change in soil
texture, structure or density,
10 yr 5/6
this may indicate the presence
Bm Fine sand coarse subangular
of a perched water table.
blocky

10 yr 5/6
2.5 yr 5/4 mottles
Bmgj Fine sand
coarse subangular
blocky

10 yr 4/3
B+ Silty clay corase angular
blocky
10 yr 4/3
10 yr 5/6
II Ckgj mottles columnar
silty clay loam
light macropores

Seepage Problems

In some cases, water can be seen seeping at the soil surface or from one side of the soil pit. These seepage
zones are normally associated with the presence of a permeable layer over an impermeable layer – where the
surface material is wet and the subsurface material is dry. One type of seepage is actually a confined aquifer
with high pressure (e.g., artesian).

Fig. 6p


FIG. 6q

In most cases, some form of subsurface interceptor drainage design is used to correct the problem if it
is well-defined. In other cases, more than one drainpipe is required or a gravel-filled trench is needed
to cut off groundwater flow. The water is intercepted long before it reaches the ground surface and the
drainpipe is installed across (not parallel to) the flowpath.

STEPS FOR PLANNING A SUBSURFACE DRAINAGE SySTEM

Begin by determining the feasibility of the project. Your investigation should provide a clear
understanding of the problem, the kinds and amounts of practices necessary, an estimate of
the cost and value of expected benefits, and the impacts of the project. This information can
often be obtained from a reconnaissance of a small problem area.
4 Hire a professional, licensed drainage contractor to conduct more detailed
examinations and surveys that determine the size of the area, the drainage
6.07p pattern, and special features where riparian vegetation, wetlands, or rock
outcrops exist.

Environmental
considerations must
be a part of the
cropland drainage
planning process –
including habitat
enhancement or
mitigation where
needed.


INFORMATION REqUIRED TO hELP PLAN A SUBSURFACE DRAINAGE PROJECT

STEP INFORMATION NEEDED

1. RECONNAISSANCE • nature and extent of drainage problem
• location and condition of existing drainage system if one already exists
• feasibility of outlet on neighbour’s property – if necessary
• whether activities or conditions on neighbouring property contribute to
drainage problem
• identify any utilities or pipelines

2. Problem analysis • watershed area
• suitability of outlet
• suitability of grades for mains
• drainage system design

3. Detailed survey and • survey information to size watershed and to size field to drain
check for legal outlet • estimate of surface runoff and water volumes/rates of subsurface flow through drains

4. Design options and costs • consideration and cost of any regulatory or municipal bylaw requirements
(e.g., proper outlet, protection of wetlands, habitat, utilities and pipelines)
• this step embraces all technical, environmental management , regulatory and
economic information to help you make best business decision

5. Approvals and funding • compliance with any regulatory or municipal bylaw requirements

BMPS FOR SUBSURFACE DRAINAGE DESIGN

The intent of subsurface drainage is to remove only the necessary quantity of water that
will ensure adequate cropland access and improved crop performance. Beyond that, it’s
important to conserve water to support crop growth during dry periods.
Design is critical. Improper design can lead to poor performance, failure, or repeated repair.
Most drainage projects are designed by licensed contractors. 6.08p
Design factors include:
� drainpipe location
� spacing
� depth
� alignment
All subsurface
� materials drainage design
should be conducted
� outlets by trained and
� correct drainage coefficient for soil type and crops grown. licensed drainage
contractors.


The following considerations are also part of the system design process:
� legal outlet (see planning section)
� drainage coefficient (drainage rate – see page XX)
� drainage depth and spacing
� cropland slope/topography
� impermeable layers
� drainage pipe material and sizing
� arrangement and systems
� drainage outlets
� surface inlets
� envelopes, e.g., filter
� environmental considerations
e
.g., quantity of water drained and proximity to natural areas such as wetlands
and riparian areas
e.g., alternative water uses, such as irrigation storage
� system implementation costs.
Design procedures must account for site factors (soil type, depth to water table, hydraulic
conductivity) and the variability of soils and drainage requirements across the area to be
drained.

For more detailed information on drainage design principles and
practices, see OMAFRA Publication 29, the Drainage Guide for
Ontario. For more information on subsurface drainage and the
Agricultural Tile Drain Installation Act, check the Drainage page on
the OMAFRA website.
http://www.omafra.gov.on.ca/english/landuse/drainage.htm


Interdependent Ecosystems at Work

Farmers can produce high crop yield in a sustain- Fig. 6R
able way without reducing water quality. To do so,
it must be understood that the soil, and the plant
and animal life it supports, operate as an ecosys-
tem. This soil ecosystem requires that the input
elements (air, sunlight, water and soil particulars)
and plant life and animal life communities be man-
aged as an integrated system. Each one of the input
elements and living communities of that ecosystem
must be kept in balance so as to optimize the pro-
duction of any one of the components.

Cropland agriculture focuses on optimization of the
plant life community of that ecosystem. A common
input element among plant life, both above and
below the soil surface, is water originating in the
form of soil moisture.

Soil Ecosystem

Within the soil ecosystem, the percent moisture
present determines if there’s enough air to allow
eco-life (living organisms) to thrive. Eco-life breaks To be effective,
down organic matter, aids nutrient release from organic matter, and assists plants in nutrient retrieval. Large, drainage systems
healthy plants increase organic matter content in the soil. Increased organic matter contributes to moisture need to work in
retention and increased eco-life, which increases nutrient availability and the production of glues that hold soil concert with other
components together. If there’s too much or too little moisture in the soil, interactions are limited – thus plant farm production
growth and soil stability are reduced. systems – such as
nutrient management,
Plant Life Community – Crop Production soil management, and
pest management.
Moisture – too much or too little – affects each component of the soil ecosystem and the plant community or
crop production system, and each affected component can affect several others.

Example 1: Soil moisture (wet) -- results in crop disease -- results in need to re-select crop
variety or crops used in a crop rotation or in sometimes increased use of pesticides.

Example 2: Soil moisture (wet) -- increases tillage to dry soil -- reduces crop residue to
further dry soil -- soil structure is damaged -- allows more flexible weed control
program or to reduce crop root disease.[Alison to check w/Don to clarify]

If the decision is made to remove excess water with subsurface drainage, then both the soil ecosystem and the
crop production plant community changes.

Soil eco-life increases soil porosity, and if crop production management will allow the use of a practice like
no-tillage, compaction will be reduced. This in turn allows the retention of crop residue and leaves crop roots
undisturbed in the soil – which in turn allows the organic matter content of the soil to increase and the soil
structure to become more stable.

By reducing soil moisture through the installation of a drainage system, crop management practices can be
deployed to increase water infiltration and percolation – reducing the erosion of soil sediment into outlet drains,
streams, and rivers.


DRAINAGE COEFFICIENT

The drainage coefficient or drainage rate is a design standard that reflects the amount of
water that can be drained from a watershed in a 24-hour period. It is the physical capacity
of the drainage system, and more specifically the main collector drainpipe. The coefficient is
expressed in units of mm/24 hr (in. /24 hr), i.e., surface equivalent. It does not reflect the
soil’s ability to transmit the water.
Part of the decision process is to ensure the soil and drainage system are balanced with
the appropriate drainage coefficient needed for the crops to be grown. In some cases,
expectations may have to be adjusted as some soils will not allow gravitational water to
move at the desired rate needed to protect the proposed crop.
The most common drainage coefficient used in Ontario is 12 mm/day (0.5 in. /day) for cash
crops on average soils. In other words, a drainage system designed to a 12 mm drainage
coefficient would be capable of removing 12 mm of excess water from the entire subsurface-
drained area over a 24-hour period.
If there is a heavier rain and more than 12 mm/24 hr needs to be removed, it would take
longer to remove the excess water. Higher drainage coefficient rates are sometimes used for
crops that are more susceptible to damage from excess moisture.
4 Choose a drainage coefficient wisely for the soil type and crop needs.

FIG. 6SI
6.09p
FIG. 6SII

To protect crops, a
subsurface drainage
system must be able
to remove excess
water from the upper
portion of the active
root zone 24 to 48
hours after a rain.

Controlling the Amount of Water Removed
Laterals determine uniformity of drainage and convey water to the header main.
The header main’s job is to collect the water from the laterals and remove it at an appropriate rate – not
any faster than is needed by the crop. The size of the area, slope of the header main, and the drainage
coefficient are three variables used to select the diameter of the header main of the various types of
material.
This is the way subsurface drainage systems meter the amount of water removed and conveyed to the
outflow.


Watershed characteristics such as intended land use, soil type, and proportion of watershed
to be drained under forest cover [Alison to confirm wording] should be considered in the
selection of an appropriate drainage coefficient.
The drainage coefficient method of drainpipe design is the most common design method
used in agricultural applications
6.10p
Check the Drainage Guide for more information on drainage rate and other design ratings
based on mapped soil series.

DRAINAGE DEPTh AND SPACING

Drainpipes used for 100 mm (4 in.) laterals should be deep enough to prevent damage from
tillage operations and the weight of the equipment – a minimum of 600 mm or 24 inches of
cover.
Check the Drainage Guide for recommended depth and spacing criteria related to the
individual soil series as mapped and published in regional and county soil survey reports.
Laterals' depth and spacing are linked, and should be selected jointly. Laterals must
be shallow enough to provide timely drainage, deep enough to remove excess water from
the root zone, and spaced appropriately to get uniform drainage at the soil surface. The goal
is to remove only the water that will impede proper crop growth.
Main and sub-main drains must be deep enough to provide an easy connection point and
a good outlet for lateral drains. Also, the maximum depth at which drains can be laid to
withstand trench loading varies with the width of the trench and the crushing strength of
the drainpipe to be used. Typical depths of header mains are in the range of 900–1200 mm
(36–48 in.) deep, but can be deeper as dictated by topography. A header main is there for
the primary purpose of transporting water to the outlet

IMPERMEABLE LAyERS

The influence of an impermeable layer on the behaviour of a groundwater table depends
on its depth below the level of drainpipe and on the drainpipe spacing. The flow pattern
and rate of the water moving toward the drain can be altered drastically by an impermeable
layer (such as dense, compacted, or heavier subsoil).
Most drainpipe spacing in Ontario is close enough together not to be affected by the
impermeable layer as long as the drainpipe is installed above it. Where the drainpipe needs
to be installed in the impermeable layer in order to get adequate depth and cover, the
impermeable layer can have a major affect. Regardless of the soil above the impermeable
layer, the rate of water movement to the drainpipe is greatly controlled by the impermeable
layer.
There are various options available to overcome this problem – each with a cost associated
with it. It is best to consult with a licensed drainage contractor or experienced drainage
designer for options. Each situation is unique. In some cases, a decision may need to be
made whether subdrainage will be effective at all.


Fig. 6T

When impermeable layers are encountered, the pipes need to be placed closer together to achieve the
effect they would have in a deep permeable soil. However, if the depth of the impermeable layer below
pipe level exceeds a fourth of the drain spacing, the flow system can be treated as if such a layer were
absent.

Drainpipe and Sizing

The maximum amount of water a drainage pipe can carry (its flow capacity) depends on
the drainpipe's inside diameter, the installation grade, and the inside drainpipe surface
roughness.
In the farm drainage industry, a more common way of reflecting drainage pipe capacity
is the number of acres that can be drained through a particular diameter of drainage pipe.
[Alison to get clarification on length/spacing vis-a-vis no. of acres]


DRAINPIPE MATERIAL GRADE OF DRAINPIPE DRAINAGE COEFFICIENT DESIGN CAPACITy

150 mm (6 in.) 0.2% slope 12 mm/day 3.8 ha
CORRUGATED 0.2 m per 100 m slope (1/2 in./day) (9.3 ac)
PLASTIC TUBING (0.2 ft per 100 ft slope)

The above row shows the capacity of a 150 mm diameter, corrugated plastic tubing drainpipe with a grade of 0.2% to remove 12
mm of water from 3.8 ha of land in 24 hours.

SMOOTH WALL 0.2 m per 100 m slope (1/2 in./day) (14.3 ac)
e.g., clay, concrete (0.2 ft per 100 ft slope)

The above row shows the capacity of a 150-mm diameter smooth wall (clay, concrete) drainpipe with the same 0.2% grade. It has
the capacity to remove 12 mm water from 5.8 ha of land in 24 hours – approximately 50% more capacity than a corrugated plastic
tubing drainpipe of the same size and slope.


The above row shows the effect of increasing slope. While the pipe material and diameter are identical to the first row, the grade is
now 0.4% instead of 0.2%. This changes the drainpipe’s capacity to 5.3 ha. More slope, more capacity.


The above row shows the effect of increasing the diameter of the drainpipe. While the pipe material and grade are identical to the
first row, the size is now 200 mm diameter instead of 150 mm. Capacity of the 200 mm corrugated plastic tubing is 7.6 ha – twice
that of the 150 mm.

Choosing the correct size of drainpipe is extremely important for main collector drains.
Too small and the system does not function properly; too large adds cost to the system.
A licensed drainage contractor can provide this information, or consult Publication 6.11p
29, Drainage Guide for Ontario, for the capacities of all sizes of drainpipe for different
grades, drainage coefficients, and material.

Besides flow capacity,
drainage systems
should also be
designed to meet
or exceed a certain
minimum velocity of
flow so that self-
cleaning or self-
scouring takes place.


Fig. 6u

A drainpipe’s flow capacity is the maximum amount of water it can carry. Flow capacity depends on the
drainpipe's inside diameter, the installation grade, and the drainpipe’s surface roughness.

Layouts and Systems

When selecting a layout pattern for a particular field or topography, aim for the following.
4 Orient lateral drains nearly parallel to the field's contours, crossing the slope – not straight

up and down. This way, water flowing downslope can be intercepted by laterals and the
system will function more effectively and produce more uniform results.
4 Orient lateral drains askew to tillage and planting pattern. This ensures that tracking of

heavy equipment will be across the drainpipe and not lengthwise, thus reducing potential
for damage. Also, tillage or row planting can alter the flow path of surface water. An
askew pattern of drainage will ensure water flowing will be better intercepted by laterals
and more uniform drainage.
4 Minimize the number of short lateral drains to reduce costs. Each lateral requires

excavation to start installation and a connection to header main.
4 Balance the number and size of header mains for capacity and to reduce costs.
4 Minimize the number of outlets to reduce costs and maintenance.
Usually, not all of these objectives can be attained at the same time. A well-designed system
will balance function with cost. Communication between the landowner and a licensed
drainage contractor is must.
Remember, a drainage system lasts a lifetime, and a little extra cost in the beginning is often
an excellent investment in the long run.


Fig. 6v

Contour lines

4
laterals

6
main
6
main
8
main

End pipe

to outlet

Header mains and sub-mains (also called collectors) can be positioned on steeper grades, or in areas of
lower elevation, to facilitate the placement of laterals.

Basic systems are either random (site-specific) or systematic.


Fig. 6W

Random System (site-specific)
The header main is generally placed near the lowest natural depression, and smaller drainpipes branch
off to drain the wet areas. Because such drains often become outlets for a more complete system
established in the higher areas of the field, the depth, location, and capacity of the random lines should
be considered as part of a complete drainage system.
Systematic Systems
Systematic patterns drain larger areas. There are two types: parallel and herringbone.
The parallel field drainage pattern consists of laterals that are perpendicular to the main drain or sub-
main. In most cases, the laterals run parallel to a field boundary. Variations of this system are often used
with other patterns
The herringbone field drainage pattern consists of laterals that enter the main drain at an angle,
generally from both sides. This system can be used in place of the parallel pattern. It can also be used
where the main is located on the major slope and the lateral grade is obtained by angling the laterals
across slope. This pattern may be used with other patterns in laying out a composite system in small or
irregular areas.

4 lign laterals across the slope, which ensures that the general movement of both surface water and
A
groundwater is across the lateral drainpipe line.
This improves the potential to capture the water for drainage, and makes drainage more uniform.
Herringbone systems can more easily achieve these objectives than the parallel system. However, in
general herringbone systems cost more to install than parallel systems, as usually there are more mains
to install and more tap connections to be made to the main.
The option of choosing the type of system layout is only available in new systems, or with complete
system replacements.


FIG. 6X

Laterals set too close to designated wetlands area are at risk of lowering the water table in the wetland.
One BMP is to place the closest drainpipe at a depth that is above the average elevation of standing water
in the wetland. The illustration shows a lateral drainpipe placed at a depth in the soil higher in elevation
than the average elevation of standing water in the adjacent wetland. This approach shouldn’t affect the
hydrology of the wetland.

PIPE OUTLETS

The system outlet is a rigid pipe that connects the main to an outlet ditch, stream or river. It
must be sufficiently large to:
� carry the water discharge from the main
� not cause any flow restrictions
� not cause any erosion
� remain stable in the ditch bank.
Drainpipe outlets are typically located 1000 to 1500 mm (3–4 ft) below the
soil surface (i.e., field elevation). They are simply a secure connection of the 6.12p
main to the surface water body.
BMPs for Pipe Outlets
The bottom of an outlet pipe should be located 300 mm (12 in.) above the
normal water level in a receiving ditch or waterway.
The discharging water may cause erosion in the receiving ditch or waterway.
4 Install an apron of rock riprap to prevent erosion.
Proper placement and
4 Equip all outlet pipes with rodent grates to prevent unwanted entry by animals. design of pipe outlets
4 Mark location of outlets with a post and marker. are key drainage
BMPs.
4 Inspect outlets each spring to ensure proper functioning and that no debris is blocking
them.


CONSTRUCTION ChALLENGES

Sedimentation – Drainpipe Plugging
Fine and very fine sands and silts are not sticky, which means it’s easier for them to move
through the orifices and into subsurface drainpipe.
4 Evaluate whether special protection such as filters or envelopes may be required. Consider
different filter or envelope materials with specific pore sizes (e.g., very fine sands 0.10–
0.05 mm diameter) to ensure sediment or sand doesn’t enter the drainpipe in these soils.
4 Talk to manufacturers to see what envelopes may best suit your soil conditions. Consider
providing them with a soil sample.
FIG. 6y

6.13p

Ap
Very fine sandy
loam
10yr 3/2

Aeg
Very fine sandy
loam
2.5 yr 5/4

B+g
silt loam
Filter materials known as 2.5 yr 4/4
Silt and very
non-woven geotextiles mottles 7.5 yr 5/8
fine sand
or woven filter cloth particles
(sock) are widely used Ckg
as pre-wrapped synthetic very fine sand
drain envelopes. These 7.5 yr 6/4
materials can be made from
polyester, polypropylene,
polyamide, polystyrene, and Water table
nylon. Filter materials can
reduce sediment loading
in drainpipe; however, no
textile is suitable for all
problem soils.

A drain envelope or sock around the drainpipe won’t interfere with
water movements, but will prevent soil particles from entering the
drainpipe openings. It can help improve and maintain optimum
flow into the drainpipe, and keep silt and very fine sand-sized soil
particles out of the drainpipe.


Ochre, an iron oxide, affects about 2% of drainage systems in Ontario. It occurs in two soil
conditions: acidic sands and poorly drained sands.
Ochre accumulates through chemical or microbiological processes, or both. It’s a natural
condition usually found where new land – sandy in nature with high organic matter – is
cleared and drained. Recognized by brilliant red deposits at drain outfalls, iron ochre can
seal drain openings very quickly.
At present there are no long-term solutions. If you encounter ochre:
� plan to replace or abandon the original system when it fails
� flush drainpipe with high-pressure water to provide temporary relief.
Connecting Old Drainage System to New System
If existing lateral pipes are relatively new, clean and not full of sediment, they are probably
working. They can be hooked into new drainpipe.
However, if they are full of sediment, then relieve [Alison to clarify] with crushed stone. Do
not directly connect the two systems, as the old system may add excessive sediment to the
new installation.

Seepage Control

Broad, flat areas that are wet due to seepage from adjoining highlands, springs, seepage
lines at two different layers of soil etc. can benefit from interception drains.
Interception drains are installed at right angles to the flow of groundwater to intercept
subsurface flows.


Fig. 6Z

Subsurface drainpipe for interception of seepage must be located properly to drain wet areas caused by
upslope water. In steeply graded depressions or draws, a layout may include a main or sub-main drain
in the draw or to one side of the draw, with the interceptor lines across the slope on grades slightly off-
contour.

Summary of Siting Recommendations for Manure Storage Facilities

If you store manure, a number of legal separation distances relating to surface and groundwater may apply to
your facility. These could include specific setbacks from wells, site investigations, observation stations for sub-
surface drains within 15 metres (49 ft) of a manure storage, and structural design.

Here is a summary of setbacks for new or expanding permanent manure storage facilities:
� a minimum of 24 metres (76 ft) from a drilled well that is at least 15 metres (49 ft) deep
� and has a 6 metre (20 ft) casing from the soil surface
� at least 151 metres (501 ft) from a municipal well
� at least 46 metres (151 ft) from any other well
� a
t least 24 metres (76 ft) from a drainpipe – whether existing or to be constructed, and with a flow-path that
is at least 50 metres (164 ft) from the nearest surface water.

Manure = fecal material + undigested feed + urine + bedding +
uncontaminated water + wastewater + other wastes.
It bears repeating: when managing manure, account for all
materials – especially liquids.


FIG. 6AA

BMPS FOR INSTALLING SUBSURFACE DRAINAGE
BEFORE CONSTRUCTION

All agricultural subsurface drainage systems must be installed in accordance with the
Agricultural Tile Drainage Installation Act. The act requires that each drainage contractor
hold a valid licence to install subsurface drainage systems on agricultural land, that each
tile drainage machine be licensed, and that each operator of a drainage machine be licensed.
Landowners installing subsurface drains on their own farm with their own equipment are
exempt.
Review the Construction section of OMAFRA Publication 29, Drainage Guide for Ontario.
It defines the minimum standard for workmanship, materials, and methods of construction
acceptable for the installation of subsurface drains.
See back cover for contact information. A list of drainage contractors is available from your
nearest OMAFRA regional information office and the Land Improvement Contractors’ of
Ontario (LICO) website – www.drainage.org

BMP ChECKLIST FOR LANDOWNERS
6.14p
Landowner Checklist – Before Construction
4 Seek professional advice to verify that subsurface drainage will be a good investment.
4 Have the soil examined if there’s some doubt of its drainage properties (see section on
diagnostics)
4 ensure soil is suitable for a subsurface drainage system.
4 Discharge water at a location where collected water can be legally discharged without
adversely affecting downstream landowners, e.g., natural watercourses, agreement
drains, municipal drains:


4 etermine whether a satisfactory outlet is available for the proposed work on the your
d
property
4 f not, negotiate agreements, in writing, with neighbours and other parties to obtain
i
authority to enter their property [add: in order to access outlet?]
4 f this does not work out, consider a petition for a municipal drain under the Drainage Act
i
– see section 7.
4 heck with your local CA regarding regulatory requirements, e.g., Clean Water
C
Act, Conservation Authorities Act -- source water protection, section 28, localized
requirements or restrictions
4 isit the municipal office to ensure municipal drain requirements will be met. [add more
V
detail?]
4 Ensure financing is in place to complete the project.
4 Locate existing drainage plans of the farm.
4 Obtain a plan for the entire farm, even though only a part is to be drained.
4 lan with consideration for drainage of upslope watersheds or neighbouring farms’
P
drainage flow.
4 Ensure the contractor is aware of the location and existence of gas and oil lines,

telephone lines, hydro lines, water lines, and septic beds. In other words, over and above
knowledge of your own utilities – “Call before you dig.”
4 Arrange mutual agreements and easements (hydro and other utilities) in advance. [add

more detail?]
4 Ensure that the contractor is aware of the location of manure storages and transfer

systems so that requirements for distance separation under the Nutrient Management Act
can be accounted for when designing the drainage system.
4 Discuss the removal and/or repair of fencing and access of livestock to the work area, or

any other on-farm practices that the contractor should know about.
4 Point out the location of existing subsurface drains to the contractor.
4 o avoid the risk of soil compaction, install drains in the summer or fall whenever
T
possible
� c
rop damage can be as little as 10% when drains are constructed with care
through crops
� m
ake use of strategic crop rotation planning, e.g., field to be drained is planted in
wheat or hay
� c
onstruction should be in reasonably dry soil so its structure is not destroyed and
drainability impaired – if the field is dry enough to work, it’s dry enough to install
drains.


Coordinating your crop rotation to allow subsurface
drainage installation in the summer or early fall has
6.15p many advantages. Most drainage is installed with
plough machines. When soil is dry (not saturated),
you’ll have the least amount of compaction and
the great amount of soil fracturing. At the same
time, some topsoil falls into the fractures. This will
optimize your drainage system’s potential in both
the short and long term.

4 Remove obstructions to construction
� check with local municipality regarding tree-cutting bylaw requirements before
removing trees.
4 Decide on the point of delivery of drainage materials ahead of time.
4 Plan a rotation one or two years in advance for the field to be drained
� use soil and cropland BMPs to improve soil conditions that will assist drain
performance.
4 Ensure that the drainage contractor:
� holds the proper and relevant licenses
� carries adequate insurance
� has checked with local Conservation Authority to determine whether any CA or
other regulations apply
� has secured the necessary permits to do the work.
Landowner Checklist – During Construction
4 Monitor and inspect the work to ensure it’s proceeding according to the
agreed-upon plan. 6.16p
4 Consult OMAFRA’s drain inspector for advice if needed – call your
OMAFRA regional information centre or the Agricultural Information
Call Centre (AICC). See back cover.


Landowner Checklist – After Construction
▼ Keep a record of the work done:
� obtain and keep a copy of the drainage plan as constructed by
6.17p contractor
� ensure the contractor has prepared a plan of the drain locations
with any changes and problem areas noted on it that may affect
future maintenance
� in the absence of a proper plan, obtain an aerial photograph of
the work area.
4 File the plan – so that there is a permanent record at the municipal
office where required. It helps locate the lines when considering drain
repair or improvements
4 Keep a copy of the drainage plan aerial photograph and any Mutual Agreement under the
Drainage Act, with the deed to the property
� keep copies of Municipal Drain
reports and plans. 6.18p
4 Watch for erosion of the drainpipe trench
following rain events over the first two years.
4 Mark the outlets, and check them each
spring for possible erosion, discharge
volume and clarity.

BMP ChECKLIST FOR CONTRACTORS

Contractor Checklist – Before Construction
4 Contact the Conservation Authority or check their website to find out
if any portion of the property is regulated. If it is regulated, find out if
6.19p approval is required to install the subsurface drainage system.
4 Ensure landowner has obtained all licenses, permits and easements
have been obtained prior to moving on the site.
4 Ensure that the final plan has been agreed-upon by landowner.
4 Notify landowner where/when design changes may have to occur
during construction.


4 Inspect the site with the owner to ensure adequate outlets are available, utilities have
been located, and possible problems identified (e.g., the soil is not drainable)
� inspect the soil profile to below drain depth
� advise the owner regarding necessary notices to third parties.
4 Agree with the owner on the financial costs and how and to whom the costs are to be
paid.
4 Determine whether there is an adequate outlet.
4 Review Occupational Health and Safety Act requirements for health and safety on the job
site, and remind workers of them.

Conservation Authority regulations may apply to some
cropland, e.g., where wetlands or floodplains occur. Consult the
local CA prior to undertaking any subsurface drainage work.

Contractor Checklist – During Construction
4 Comply with applicable legislation. 6.20p
4 Adhere to Occupational Health and Safety Act requirements for health and
safety on the job site.
4 Follow all safety procedures. Keep casual observers away from construction
operations.
4 Keep casual observers away from construction operations.
4 Erect safety barriers to prevent public access to the work.
4 Restrict all machine and truck movement on the field to designated paths.
4 Do not backtrack plough trenches to compress them; it may damage the drains
and drainability.
4 Inspect all drainage materials before installation to ensure they’re free from defects and
meet approved quality standards for their intended purpose.
4 Store drainage materials so they won’t be damaged before installation.
4 Check old drainage systems for agronomic and hydraulic efficacy.
4 Don’t connect drainpipes that appear to be polluting.
4 Minimize the number of outlets to reduce system maintenance.
4 Maintain and operate the installation equipment so drainpipe is installed in accordance
with the designed grade and depth.


Contractor Checklist – After Construction
4 Ensure the following information is on the plan to be left with the
landowner:
6.21p
� date of construction
� name of the contractor
� alterations to the original plan
� drainpipe type, size, footage, and materials
� details of construction problems
� location of utilities, sand pockets, springs, etc. that may affect
future maintenance
� suggestions for future work additions.
Landowners must
know the exact
location of subsurface BMPS FOR MANAGING SUBSURFACE DRAINAGE
drainpipes on their
property. This will
INSPECTION AND MAINTENANCE
help with subsequent
monitoring, Annual maintenance and good soil management practices are your best insurance for the
maintenance and successful long-term operation of your drainage system.
repair work.
4 Adopt soil management BMPs – drainage-system performance may be hindered by poor
practices (see pages XX–XX).
4 Check outlets regularly:
� make more thorough inspections in the spring or late fall when the soil is wet and
the drain is running
� mark locations in need of repair or maintenance
� make sure outlet marker is still in place and clearly visible.
4 Schedule maintenance or repair work when field conditions are drier.
4 Keep up a preventative maintenance program, including:
� keeping a plan of the drainage system
6.22p
� cleaning catch basins and outlets
� repairing the outfall.

The precise location of subsurface
drainpipe lines is made possible with
the use of Global Positioning Systems 6.23p
and on-the-ground spatial referencing.
Drainage contractors are using this
technology to install subsurface drainage
and for drainage system maintenance and
repair work. Aerial photos and drainage
maps can also be used to pinpoint
drainpipe location with a high degree of
accuracy.


Cropland drainage systems require routine monitoring to
ensure that the entire system is performing the expected
6.24p function of safely conveying water to a proper outlet.
Make routine and periodic inspections of drainage
system components to ensure minimal environmental
impact.

PROBLEM VERIFICATION

In practice, you will notice the inefficiency of a drainage system when water stands on the
field for a long time, and in spring when the topsoil remains wet too long. Isolated wet spots
in the field, surface wash-ins, and blowouts along the drain line are indications of drain
problems.
The value of a proper drainage plan or aerial photograph of the system becomes very
apparent during maintenance.
For more information on drainage system maintenance and management, please refer to:
� OMAFRA Factsheets, Maintenance of the Drainage System, Agdex 553/725 and
Management of Drained Fields, Agdex 555/632
� the OMAFRA Drainage website
http://www.omafra.gov.on.ca/english/landuse/drainage.htm
� your local Conservation Authority.

TROUBLEShOOTING

Diagnosing and troubleshooting drainage problems is an ongoing process that’s both
simple and complicated, and requires the landowner to pay attention to changes in the field
drainage conditions.
Take note of changes to the wetness of a field or specific location, or to the uniformity of
crop growth. After a rain, the soil will change colour as it dries and usually form a pattern.
Pay attention to these details. If the pattern changes, there may be a problem.
Some problems are very obvious in the form of very visual wash-ins or washouts or water
bubbling to the surface. These are abrupt changes. Other problems occur over time, e.g.,
iron ochre, tree roots, partial collapse of a plastic tubing drain, etc. These are identified by
changing conditions.
In most cases, a standard approach to fully identify and diagnose the problem is to expose
the drainpipe to the downflow side of the wet area. Excavate the soil, uncovering the
drainpipe in the upstream direction until the problem is found. Diagnose and repair.
The following chart lists the most common drainage problems that you might encounter and
what to look for.


TROUBLESHOOTING SUBSURFACE DRAINAGE

ITEM WHAT TO LOOK FOR POSSIBLE CAUSES PREVENTATIVE CORRECTIVE
(SYMPTOM) MEASURES MEASURES

BLOCKED • water bubbling to • collapsed or crushed • ensure proper design • repair immediately, and
DRAINPIPE surface like a spring drainpipe depth, location, and replace damaged
above the drainpipe • damaged or poorly installation drainpipe
• holes in soil above installed drainpipe • avoid travelling over • use rigid or double-wall
drainpipe connection drainpipes with heavy drainpipe under high
• water not draining • sediment buildup or equipment in wet traffic areas
• trees close to drainpipe blockage in drainpipe conditions • relocate/resize drain
• tree roots in drainpipe • do not plant water- • remove problem tree(s)
• dead animal blocking loving trees within • use non-perforated
drainpipe 30.5 m (100 ft) of a drainpipe along
drainpipe– all other problem tree
trees 15 m (50 ft) • use high-pressure water
system to clean out line
• install/repair rodent
guards at outlets

BLOWOUTS • similar to blocked • poor design, inadequate • ensure drainpipe is • replace drainpipe with
AND CAVE-INS drainpipe except water grade, undersized properly sized to larger diameter
will go back down hole drainpipes handle flows • if high pressures persist,
as well as come out • drainpipe slope changes • use a relief well in the vent as necessary-
from steep to flatter design or use larger- relief well
causing pressure buildup diameter drainpipe • replace damaged
• partial collapse of • avoid travelling over drainpipe
drainpipe resulting in drainpipes with heavy • repair poor or damaged
flow restriction and equipment in wet connections
pressure buildup conditions • make use of flow
• faulty connections • ensure proper restrictors on surface
• too much surface water installation inlets
diverted to subsurface
system

TREE ROOTS • drainpipes near trees • some species more • route drainpipe 30 m • reroute drainpipe
• water not draining problematic than others (100 ft) from water- beyond crown of trees
• land wetter than other • more acute in loving trees, and at • replace plugged areas
areas of the field continuous flowing least 15 m (50 ft) from • consider non-perforated
drainpipe all other trees or install drainpipe in problem
sacrificial drainpipe areas
next to tree • remove problem trees
• se non-perforated
u
drainpipe within
15 m (50 ft) of tree


TROUBLESHOOTING SUBSURFACE DRAINAGE

ITEM WHAT TO LOOK FOR POSSIBLE CAUSES PREVENTATIVE CORRECTIVE
(SYMPTOM) MEASURES MEASURES

SEDIMENT AND • decreased flow capacity • no envelope on • verify presence of • replace with envelope-
DEPOSITS FROM causing areas of field to drainpipe problem soils wrapped drainpipe
UNSTABLE SOILS drain more slowly than • use filter cloth • use high-pressure
normal • design with self- cleaning equipment
• excess sediment in cleaning (steeper) grade to remove sediment
drainpipe

QUICKSAND • soil is saturated at • upward pressure from • install drainpipe • replace with solid
depth or near surface groundwater in fine and when dry drainpipe in area of
and will not settle very fine sand and silty •install on solid bedding quicksand
soils • use crushed stone
bedding under drain

IRON OCHRE • reduced drainage each • natural condition of • very difficult to identify • replace drainpipe
year in low area of field low-lying area of field ahead of time • consider controlled
• reddish-orange slime triggered by installation • consider controlled drainage during growing
at outlet of drainpipe and drainage during growing season, and flooding
• crusting around introducing oxygen season, and flooding drainpipe in non-
drainpipe when dug up drainpipe in non- growing season to
• gelatinous growth in growing season to slow down action
drainpipe slow down action

DAMAGE • water ponding above • compaction layer • stay off wet soils • introduce deep-rooted
TO SOIL drain, yet soil somewhat • drainpipe installed in • modify axle weights crops into rotation
STRUCTURE dry underneath surface wet conditions • vary tillage depth • add organic matter
layer • reduce tillage passes • reduce tillage

HIGH TRAFFIC • drainpipes under • compaction • use rigid drainpipe • replace drainpipe if
AREA laneways • crushed drainpipe across traffic area necessary
• water not draining

GRASSED • drainpipe exposed in • drainpipe too close to • offset drainpipe from • install new drainpipe
WATERWAY bottom of grassed channel centre centre of grassed away from channel
waterway • prolonged flow in waterway centre
grassed waterway • nstall larger drain to
i
reduce length of time
of overland flow

LOSS OF • reduced depth of • organic soils over- • install subsurface • change cropping
ORGANIC SOILS organic soil exposed to oxygen drainpipes in organic system or land use –
• mineral soil layer • drainpipe installed too soils and above mineral less tillage, more
exposure close to underlying soils vegetative cover
• black and discoloured impermeable mineral • manage high water
snow soils levels in non-growing
season to avoid wind
erosion and oxidation
of soil


TROUBLEShOOTING SUBSURFACE DRAINAGE

ITEM WhAT TO LOOK FOR POSSIBLE CAUSES PREVENTATIVE CORRECTIVE
(SyMPTOM) MEASURES MEASURES

POOR QUALITY • odours or solid waste • manure storage, • keep drainpipes away • take immediate action
WATER in drainpipe at outfall milking centre, septic from source of – locate source and
(FARMSTEAD • odours or solid waste in or other wastes contamination eliminate connection
LOCATION) drainpipe dug up just (vice-versa also true) • decommission
downslope from connecting drainpipe
farmstead • reroute drainpipe away
from source

POOR QUALITY • odours, unusual brown • poorly timed • reduce application rates • reduce application rates
WATER discolouration, or applications, untimely • pre-till to break • pre-till to break
(FIELD manure in outflow rainfall after flow-paths flow-paths
LOCATION) application, excessive • split applications • split applications
NON-POINT application rates, soil • improve application • improve application
SOURCE cracks or worm tunnels, timing timing
accidental spill in field • apply manure when • apply manure when
drainpipes not flowing drainpipes not flowing
• develop emergency
response plan
• consider installing
in-line viewing stations
for visual check of
water quality flowing in
drainpipe – same unit
can also be used to stop
flow in some instances
if needed

6.25p 6.26p

A 100 mm (4 in.) drain containing 20 Drainpipes near treed fencerows are
mm (3/4 in.) of sediment will have its at risk of being clogged by tree roots
discharge reduced to 80% of capacity. of fast-growing trees such as poplars,
With 30 mm (1 in.) of sediment, the willows, elm and soft maple.
capacity is reduced to 65%.


6.27p 6.28p

As with pipe outlets and surface inlets, regular If existing lateral drainpipes are relatively new,
inspections are an excellent early-warning system to clean and not full of sediment, they are probably
help you troubleshoot. working. They can be hooked into new drainpipe –
once you verify they are working properly. however,
if existing drainpipes are full of sediment, then
relieve with crushed stone. Do not directly connect
the two systems, as the old system may add excessive
sediment.

6.29p When drains are being installed, ensure you’re not
hooking up to existing drains that may be a source of
pollutant / wastewater. No direct or illegal hookups.
[Alison to clarify] Also respect separation distances.

6.30p

6.31p


PHOTO TO COME
6.32p

6.33p

PHOTO TO COME

6.34p

PHOTO TO COME

6.35p

PHOTO TO COME

6.36p


CLEANING CLOGGED DRAINPIPE

High-pressure techniques are needed to remove root systems. This service is available by
contract. The water jet displaces material in the drain by using just enough water to move
the jet in the drainpipe. Sediment and debris are contained on-site during these operations.
Changes in the soil structure outside the drainpipe due to the flushing operation may create
additional sedimentation problems.

EMERGING TEChNOLOGIES

In specific conditions, a subsurface drainage system can be used to maintain soil moisture at lev-
els that meet crop requirements throughout the growing season.
6.37p
Controlled drainage uses water-table-level control devices and drainpipes to hold back some
of the water that would normally drain to an outlet. By doing so, more water is made avail-
able for plant growth by capillary action and for a longer period of time. Under normal drainage
conditions, the water table over time is lowered to the bottom of the drainpipe. With the control
devices, the lowering of the water table is managed to a strategic depth conducive to root devel-
opment and crop growth. Without additional rain, the water table will continue to lower because
of evapotranspiration and normal deep percolation.

Controlled drainage may also be used to hold back soil water in non-cropping seasons (winter). It
has been successfully used in muck soils to reduce soil loss in the non-growing season.

Sub-irrigation adds another dimension to the system. The water table is maintained at the
optimum location for plants to use by adding water to the drainage system with pumps. Hence, a
water supply is required to make this system function. The water supply can be a separate source Controlled drainage has not been extensively
such as a river, stream or well, or it could be water that was captured from the drainage system tested in Ontario. The consensus to date is
and stored for irrigation use. mixed. Site requirements are too limiting.
There are few sites with the precise soil
For both practices, soil water contaminants may be withheld or allowed to be processed to other and slope requirement necessary to make
less environmentally harmful forms. (For example, nitrate is converted to nitrogen gas through controlled drainage effective. Further, it is
denitrification.) difficult to maintain the uniformity of soil
water table depths necessary to maintain
Research continues to evaluate the effectiveness and conditions under which these technologies
desired soil moisture levels.
may be used. Site conditions must be appropriate – such as flat terrain, proper lateral spacing,
and an impermeable layer at or below but near the drainpipe depth – to make effective use of this
emerging technology.


Fig. 6BB

Water table

Impermeable
layer Conventional

Water table

Impermeable
layer Controlled

Water table

Impermeable
Sub Irrigation
layer

Normal systematic drainage design in Ontario – with shallow drainpipe depths – approximates the same
intended effect of controlled drainage. Sub-irrigation is similar to controlled drainage except that the
water table is maintained at the optimum location for plants to use by adding water to the drainage
system with pumps Controlled drainage / sub-irrigation does show promise where soil and site conditions
are suitable and the water supply is adequate.t

B E S T M A N A G E M E N T P R A C T I C E S � B M P s T H A T C O M P L E M E N T C R O P L A N D D R A I N A G E 1 4 5

BMPs THAT COMPLEMENT
CROPLAND DRAINAGE

Not all drainage BMPs relate directly to the planning and management of agricultural drainage infrastructure.
Soil health and management practices can help to reduce the need for cropland drainage BMPs caused by soil
degradation. Other practices can help to reduce the concentration of crop inputs moving into and out of crop-
land drainage systems. This chapter introduces several of these BMPs, which are explored fully in other BMP
books.

BMPS FOR SOIL MANAGEMENT

Many problems with wet soils can be prevented or rectified with soil management BMPs.
Soil management BMPs include practices that:
� add organic matter
you will definitely find some overlap among the
� reduce organic matter loss BMPs that address a particular problem. This is good
� improve structure and porosity news: adopting one measure can often help you on
several fronts.
� reduce seedbed crusting, and
� reduce the risk of compaction.

ORGANIC MATTER ADDITIONS

Growers can directly affect the organic content of their soils. Excessive tillage, soil erosion
and poor crop rotation will accelerate the loss of organic matter. On the other hand, there
are a number of BMPs that maintain and improve organic matter:
Organic matter:

7.01p � plays a major role in moisture retention,
helping crops withstand drought
� contributes to the chemical and biological
properties of the soil
� is a source of and exchange site for nutrients
� affects the fate of applied pesticides
� contributes to the physical properties of
the soil (e.g., structural strength, erosion-
resistance)
Soil organic matter is a very small part of the
� organic matter provides glue-like substances
soil with a large role to play. Many soils used
for crop production have soil organic matter that act to stick individual particles together to
levels between 2 and 4%. And yet, organic form stable aggregates and good soil structure.
matter is a very important component –
second only to soil texture.


7.02p 7.03p

4 Cover crops such as rye, oats and barley are 4 Forages in rotation such as grass or
suitable cereal cover crops for most soils. legume-based hay crops will add some
Others such as field peas, buckwheat, and organic matter and will greatly improve
oilseed radish can also be useful. Cover seedbed structure in the short run. Suitable
crops improve surface drainage conditions. forages include: trefoil, red + alsike clover,
orchardgrass, and timothy.

Manure and biosolids can be applied to light soils, but should be
7.04p added at times that leaching losses are minimized. Make sure crops
can use manures at time of application. Note:
• coarse-textured soil can’t absorb nitrates in the fall and will leach
in light soils (i.e., excessively drained or natural rapidly drained)
• some rapidly drained gravels and coarse sandy soils are not suitable
for liquid manure applications – make sure that the application
rates don’t exceed the soil’s ability to absorb the manure nutrients
and bacteria.

FIG. 7A

Cropland Riparian area

Grass and
buffer

Water table

40 cm


CONSERVATION TILLAGE SySTEMS

Soils with higher organic matter levels have more resilient structure. Gravitational water
moves more freely in well-structured soils.
Conservation tillage systems – including ridge tillage and no-till – involve tillage and
managing the residue left from the previous crop. Mulch tillage mixes residue into the soil
surface to reduce wind and water erosion.

7.05p 7.06p

4 Mulch tillage refers to any system where 4 No till refers to any system where the soil is
the soil is disturbed between harvesting not disturbed between harvest of one crop and
one crop and planting the next, and at planting of the next – although some tillage
least 30% of residue is left on soil surface. may be done in strips or zones prior to or during
Mulch tillage systems improve infiltration planting. Equipment modifications are necessary
rates and reduce runoff. for seed, fertilizer, and pest control placement.

REDUCING SURFACE CRUSTING

Following the rapid wetting and drying of an 4 Adopt tillage
overworked seedbed, a solid sheet forms (0.2–5 cm options that
or 0.07–2 in. thick) that is tight enough to prevent 7.07p maintain at least
water infiltration and crop emergence. A track 50% of aggregates
record of poor soil management (e.g., erosion) and greater than 2
mm (0.07 in.)
few organic matter inputs is most often the cause.
or use reduced
4 Rotate crops to include soil-building crops such secondary tillage,
as grasses and legumes or cover crops. no-till or mulch
tillage to reduce
4 Use manure management to build soil organic soil structure
matter. degradation and
leave crop residue
4 Use timely tillage. Prevent soil clodding by tilling on the soil surface.
only when soil moisture is suitable. Only use a
rotary hoe to break up the crust if a crust has
formed before the crop emerges: this is a remedial measure.


REDUCING COMPACTION

Compaction is the process of increasing soil density by packing soil particles closer together.
It can occur anywhere in the soil profile, but tends to be seen near the surface or at plough
depth. Soil compaction can impede the movement of water through soil by gravity. Soil
management BMPs can lessen the impact of compaction on soil structure.
4 Time operations with care. Stay off wet fields. Check that soil has proper moisture
conditions for working at tillage depth.
4 Use longer crop rotations that include forages/cereals. Soils with subsurface drainage can
grow a wider range of deep-rooted crops (e.g., alfalfa).
4 Adopt a no-till crop system where only the immediate crop row area is tilled, or use strip
tillage.
4 Adjust tillage equipment. Ensure it lifts and shatters soil as opposed to pulverizing and
grinding . Alternate tillage depth so that tillage pans aren’t created, or try no-till.
4 Be mindful of using appropriate tire size, pressure adjustment according to your field/soil
conditions.
4 Limit the amount of traffic, including tillage, across a field.

7.08p

4 Use controlled traffic strategies such as tramlines or strip tillage.


NON-TILLAGE BMPS FOR CROPLAND CONSERVATION

Non-tillage practices can help to control erosion by reducing the effect of steep slopes and by
increasing soil cover. Conservation practices include cropland buffers and contour farming.
4 In areas of extreme erosion, consider retiring the land with tree plantings.
Two conservation practices examples are shown below.

Contour strip cropping
alternates strips of row
7.09p crops, cereals and forages
on the contour level.
This slows surface flow
and increases infiltration
rates.
7.11p

7.12p
PHOTO TO COME Cross-slope strip cropping
maintains strips of row
crops, cereals and forages
7.10p at uniform widths across
the main, simple slope.
On complex slopes,
this makes it easier to
manage than contour
strip cropping; however,
WaSCoBs may be necessary
PHOTO MISSING
to prevent severe rills in
the draws. Typically, a 7.13p
combination of practices
is necessary for effective
erosion control.


BMPS TO MINIMIzE CROP INPUT RUNOFF

Without careful consideration and management, crop inputs applied to cropland can find
their way to ditches and streams.
Implement BMPs on the land adjacent to the surface drainage ditches or surface inlets
(including blind inlets) to reduce the risk of these materials entering the cropland drainage
system. Take special care when applying nutrients, manure, or pesticides in fields where
surface inlets have been installed.
By combining the BMPs in the previous section with BMPs for nutrient and pesticide
application, you’ll drastically reduce the potential for contaminated drainage outflow.

NUTRIENT APPLICATION

Crop nutrients are applied to soil in the form of inorganic fertilizers, manure and biosolids.
The following BMPs are suitable for the application of all forms of crop nutrients.
4 Test soil regularly. Follow soil test results. In this way you’ll apply only what’s needed –
reducing risk of loss from the soil system.
4 Calibrate crop nutrient (e.g., manure) application equipment. Accurate application rates
and uniformity will reduce the risk of nutrient loss from cropland.
4 Prepare and follow a nutrient management plan for your operation. It will help you
balance crop nutrient requirements with nutrient applications, and identify effective
separation distances.
To reduce the risk of manure in outflow, follow these BMPs.
4 Reduce manure application rates if there’s a chance for manure in outflow – i.e., when
soils are too wet, early spring, late fall, and following several consecutive days of rain
• always consider reduced rates before pre-tillage on highly erodible, fragile soil.
4 Spread manure when the ground is dry and no water is flowing from the drainpipe.
4 Pre-till land before applying liquid manure to break up large pores (due to cracking,
wormholes, and other naturally occurring large pores) and reduce infiltration to
drainpipes. However, be aware that pre-tillage can significantly increase the risk of soil
erosion that will carry nutrient and pathogens into surface waters. Reduced application
rates are always the most responsible option.

The injection method
of application ensures
7.14p immediate incorporation
of surface-applied
nutrients. Incorporate
manure within 24 hours
following application.
This will prevent runoff to
surface waters.


4 Don’t spread if any of the following conditions is present:
� rainfall occurs shortly before application
� heavy rains are forecast within 12–24 hours of spreading on cropland with
subsurface drainage
� ground is frozen and/or snow-covered.
7.15p
4 Incorporate manure when and where there is risk for soil erosion.
4 Develop a monitoring and contingency plan for manure application.
React immediately to spills and leaks. This will reduce the risk of
manure entering the agricultural drainage system.

Prepare spills
contingency plans
7.16p and communicate
them to staff and
family members.
Monitor pipe outlets
after applying liquid
manure.

7.17p

BMPS FOR LIqUID MANURE AND BIOSOLIDS ON CROPLAND WITh SUBSURFACE DRAINAGE:

4 use control valves for transfer of liquid manure from storage to field, where feasible, to
shut off the system if a manure leak is detected

4 use inspection chambers on subsurface drains at farm lot lines so that you can see and 7.19p
take samples of subsurface drain water [Alison to check re: John’s comment]

4 ensure milking centre washwater treatment systems or household septic systems are not 7.18p
connected to field subsurface drainage systems – this practice is illegal!

4 create a contingency plans for spills – specify what to do if a problem arises, who to
contact, etc.

4 set up a visual inspection schedule of subsurface drains e.g. spring, fall, after major
For more information on
storm events, during spreading of liquid manure etc .
nutrient management,
� keep written record of observations – if contaminants are suspected, please see the Best
implement your contingency plan Management Practices
books, 5.61p Managing
4 ensure outlet areas are not subject to scouring with erosion – protect with filter cloth and Crop Nutrients, 5.62p
rock rip-rap where necessary
Manure Management
and 5.63p Nutrient
Management Planning.


PESTICIDE APPLICATION

Herbicides and other pesticides are very expensive, and must be applied judiciously in crop
production systems to help you reach goals for crop production efficiency.
4 Choose those herbicides/pesticides that are more effective and have the least
environmental impact.
7.20p 4 Employ integrated pest management strategies. Identify, monitor, and determine critical
pest and economic thresholds – before selecting pest control methods.
4 Read and follow the label instructions before making application. Do not exceed
recommended rate and frequency of pesticide use.
4 Select nozzles to attain the droplet size spectrum that will bring about proper coverage,
deposition and to reduce drift.
4 Calibrate your application equipment before using it.
4 Don’t spray pesticides if weather is inappropriate, e.g., rain or high wind. Washed-off
7.21p insecticides and fungicides can cause off-site damage and reapplication is expensive.
4 Ensure you comply with recommended separation distances. If not otherwise stated,
leave 15-metre (49 ft) buffer strips between your treatment and riparian areas.

PHOTO TO COME When applying
pesticides, follow
label directions for
7.22p separation distances
from environmentally
For more information
sensitive areas.
on pest management,
see the BMP books,
Integrated Pest
Management and
Pesticide Storage,
Handling and
Application.

7.24p
7.23p

Select nozzle size and application conditions that Grower Pesticide Safety Course training and
will minimize spray drift. certification are required to purchase and apply
pesticides on cropland in Ontario. See www.opep.ca

B E S T M A N A G E M E N T P R A C T I C E S � B M P s F O R D R A I N A G E O U T L E T S A N D O U T F A L L S 1 5 3

BMPs FOR DRAINAGE OUTLETS
AND OUTFALLS

Outlets and outfalls are very important features of a drainage system that need careful design, construction,
protection, and maintenance. This chapter explores various types of surface and subsurface drainage outlets,
and what each needs to function well. We’ll also look at new technologies for improving outfall quality.

Surface Drainage Outlets

An outlet is a transition point in any system that removes water, and results from a change
in shape and/or size, change in grade, or a change from a closed to an open system. This
transition or change brings the potential for erosion. With careful planning and design,
surface water can be moved from the field to the receiving waterway with minimal impact.

Surface Waterway Outlets

One of the major causes of ditch bank failures and washouts is concentrated surface flows
entering the ditch over the ditch bank. Even small flows – those directed to the ditch by a
plough furrow – can cause damage that requires costly repairs. The designer or inspector
should locate these areas and provide special means of entering these flows into the ditch.
Two common methods of safely entering these flows are using drop inlets (pipe, catch
basins etc.), and small chute spillway drop structures.
Drop Inlets
Drop inlets or special surface water inlets are used to introduce surface flows into an open
ditch. Many companies pre¬fabricate different types of catch basins and drop pipes that do
a good job when properly selected and installed. The trash guard, riser pipe size, outlet pipe
size, and outlet protection are all points to consider when in¬stalling a drop inlet.

Fig. 8A


Small Chute Spillway
The small chute spillway drop structure is designed to have a slope equivalent to the bank
slope of the receiving ditch. This means field operations can be performed parallel to the
ditch bank without undue obstruction. These smaller structures are suitable for watersheds
of 4 ha (10 ac) or less.

Fig. 8B

Grassed Waterway Outlets

Grassed waterways usually exit into ditches and streams, and it’s important to design and
construct non-erosive outlets at these locations. Construct a chute spillway, drop pipe inlet,
or grade control structure to carry water from the grassed waterway level to the outlet
elevation.
If a waterway exits into a low-lying swampy area, the waterway cross-section must be
flared out – wider and shallower – as it enters this area.
A grassed waterway must be designed and constructed so that the water exits the channel
at a proper outlet. If water isn’t carried to a proper outlet, further erosion and cropland
drainage problems will occur on adjacent lands. If a neighbour’s land is involved at the
outlet, consider the following alternatives:
� d
iscuss the project with the neighbour and encourage the extension of the waterway
across their property, or
� r
eceive written permission from the neighbour for the outlet location and have the
agreement registered.
Both the contractor and farmer are responsible for the waterway outlet installation. If
a future problem develops, both parties may be liable for damages caused to the lower
landowner.


PRIVATE OPEN DITCh OUTLET

Ditches are much deeper than grassed waterways. They often carry water over long periods
of time and at higher velocities. Protect the ditch outlet from erosion by one or more of the
following methods:
4 design for gradual widening and increase in slope of ditch banks (e.g., from 2:1 to 4:1)
approaching the ditch outlet
4 decrease in grade approaching the ditch out¬let
4 install rock riprap or gabion mat liner in the ditch bottom
4 install a drop structure where there’s a drop of more than 30 cm (1 ft) 8.01p
at the ditch outlet, e.g., rock chute, grade control struc¬ture or a drop
pipe structure.
Rock Spillway
A ditch may empty into a lake or river and require protection from waves
or cur¬rent. If it empties into another channel, that channel may need
protection from erosion.
Occasionally a ditch flows from very steep terrain to a flat area and
becomes a wide, shallow, grassed waterway. In every case, protect the
transition area from erosion.

BMPS FOR SUBSURFACE OUTLETS

The drainage outlet is the single most important component of a subsurface drainage
system. It should receive adequate care and attention during installation and be inspected
for necessary maintenance at least twice per year. The outlet should be protected from
erosion, settlement, rodents, silting, shifting, and damage by machinery and livestock.

SySTEM OUTLETS

The starting point in planning a subsurface drainage system is normally determining the
location of the outlet. Cropland drainage systems may discharge by gravity into natural
watercourses or constructed communal drains (ditches or large-diameter pipes).
4 For new agricultural drainage systems, the drainage contractor should ensure that all
potential outlets are deep enough and have been calculated to be of sufficient capacity to
carry all the drainage water from the entire system.
4 For existing cropland drainage systems, the contractor must verify the adequacy and
integrity of the outlet before proceeding with the design of the system.

CAPACITy AND DEPTh OF DITCh OUTLETS

4 The drainage contractor must ensure the outlet ditch has the capacity to remove the
surface runoff from its watershed fast enough to prevent crop damage.


The outlet ditch should be deep enough to allow at least 30 cm (1 ft) of clearance between
8.02p the bottom of the drainpipe and the normal low-water stage in the ditch when drains are
installed at the specified depth. This should never be below the ditch’s water line.

MAIN COLLECTORS

The drainage contractor should:
4 confirm the main drainpipe has sufficient capacity for the proposed drainage system in
addition to other systems it serves.
� note: the main drainpipe diameter is the key to safe metering rate of water
removal
4 ensure the main drainpipe is deep enough to permit the new system to be installed at the
specified depth
� note: the main drainpipe diameter is the key to safe metering rate of water
removal
4 confirm any existing subsurface drains to be used for the outlet are in good condition and
working properly
4 consider using large-diameter header drainpipe and fewer outlets when upgrading
cropland drainage systems – this can help reduce ditchbank erosion

AGRICULTURAL DRAINAGE AND SINKhOLES

A sinkhole is a depression in the surface of the landscape where surface water freely flows
into the ground. After the water enters the ground, sometimes it travels horizontally and
resurfaces at the ground, and other times it travels vertically. Landowners and contractors
need to be cautious working around them, as it is uncertain where the water may go.
There are many types of sinkholes. Typically, surface-expression sinkholes are those that
develop where depth to fractured bedrock is less than 15 metres (49 ft). The bedrock is
most often sedimentary and prone to weathering (e.g., limestone, dolostone, and gypsum).
The bedrock minerals are dissolved by the mild acidic water seeping into them from the
root zone. Water flows through the cracks and fissures. Over long periods of time, the voids
within the rock allow the overlying soils to erode into the bedrock. In some cases, this
erosion causes a depression on the ground surface.
In Ontario, most sinkholes are found in a few localized areas where bedrock layers and
conditions prone to this kind of weathering exist.
If you do have them, be aware that sinkholes can be significant groundwater recharge
areas. However, they short-circuit the shallower aquifers and recharge directly into the deep
bedrock aquifer. Because these systems are diverse and complex, the interaction between
surface water and groundwater is very hard to predict.
It’s known that sinkholes provide a direct and unfiltered route for surface water to interact
with bedrock aquifers. These deep bedrock aquifers are often a drinking water source for
rural landowners and in some cases, urban centres. Sinkholes are potential pathways for
a variety of unfiltered contaminants to enter into the bedrock, including nutrients, bacteria
pesticides and chemicals.


Sinkholes function as natural drainage features, and due to their efficient drainage
capabilities are still being used today in a variety of drainage situations. In southwestern
Ontario and along the Niagara Escarpment, both surface and subsurface drainage have used
sinkholes as outlets.
4 Contractors should not use sinkholes as an
outlet in new cropland drainage schemes. Drains
8.03p
constructed under the Drainage Act should not
use sinkholes as a “safe and sufficient” outlet.
4 If there is no alternative outlet, consider
subsurface filter systems or constructed wetlands
to treat water prior to flow into sinkholes in
existing agricultural drainage systems
4 Establish permanent grass buffers around
sinkholes for a recommended 15 metre (49 ft) radius to ensure better surface water
quality entering the sinkhole, and for general safety.

PUMP OUTLET

Contractors will suggest a pump outlet for drainage sites where a gravity outlet is not
available, and a power source is available and practical.

OUTLET CONSTRUCTION

Pipe Materials FIG. 8C
4 Use non-perforated
corrugated metal pipe or
plastic pipe with a minimum
length of 3 metres (10
ft). Plastic pipe must be
chemically treated to resist
degradation by ultraviolet
light.
4 Angle the subsurface
outlet pipe downstream so
as not to impede normal
subsurface drain flow, and
discharge 0.3 metre (1 ft)
minimum above normal
water level or ditch bottom PHOTO TO COME
– see illustration.
8.04p

To reduce bank erosion around subsurface outlets, install
non-perforated rigid pipe (minimum length of 3 metres or
10 ft.) with a rodent gate, filter cloth and rock riprap. Install
a header drainpipe to reduce the number of outlets.


Pipe Placement
4 Extend the drainpipe into the outlet pipe 15 cm (0.6 in.) minimum. The joint is to be
tightly sealed so as to be leakproof. Concrete grout can be carefully placed in the space
between the drainpipe and the outlet pipe, and filter cloth wrapped around the joint.
4 Install the outlet pipe immediately after digging the trench. Backfill material should be
well compacted in 100 mm (4 in.) layers.
4 Seed the backfilled ditch/stream bank immediately. A recommended seeding mixture is
creeping red fescue at 20 kg/ha (18 lb/ac) and bird's-foot trefoil at 12 kg/ha (11 lb/ac).

OUTLET PROTECTION

Rock Riprap Apron
4 Choose flush-mount outlet pipes, since they do not extend out beyond the channel
8.05p bankslope where they could otherwise be damaged by ice and floating debris.
4 Provide erosion control protection around the flush outlet. A recessed apron of rock
riprap with a filter cloth underneath should be installed below the outlet pipe on the ditch
bank and extended across the ditch bottom. Rock riprap equivalents such as geoweb,
interlocking concrete blocks, or cable concrete block material will also provide adequate
erosion control at the outlet.
Seepage Collars for Unstable Soils
4 Use an anti-seepage collar if working in unstable soils. The collar prevents water from
tracking along the outside of the outlet pipe and causing a washout.
Prevent bank erosion
at outfall areas by
using rock riprap FIG. 8D
aprons underlain by
filter cloth.


Anti-seepage collars may be purchased from suppliers of drainage materials. They may also
be constructed of light gauge metal, heavy polyethylene on a frame or concrete.
An anti-seepage collar should have minimum dimensions of 76x76 cm (30x30 in.) for
outlet pipes 3 metres (10 ft) in length. For longer outlet pipes, increase the collar dimensions
by 15 cm (6 in.) total for each 0.6 metre (2 ft) increase of length over 3 metres (10 ft).
For example, a 5 metre (16 ft) outlet pipe length requires a 122x122 cm (48x 48 in.) anti-
seepage collar.
Rodent Gates
4 Use a swing gate on all outlets to exclude rodents and other small animals 8.06p
� screen mesh openings should not be less than 2.5 cm (1 in.)
� swing gates, rather than fixed screens or grates, should be used where surface
water enters a system directly to allow any debris to move out the pipe.
Surface Runoff near Outfall Areas
When it’s necessary to construct a drainage outlet in a very high ditch bank, erosion can be
prevented by the following methods.
4 Install a properly designed drop-pipe structure to move the water down to the lower
elevation. This structure could be sized large enough to serve as a junction box for
several main lines.
The surface water inlet should be avoided if the subsurface drainpipe may have winter flow,
e.g., springs, since this could cause blockage by ice buildup. A trash guard or inlet grate
should be secured on the drop-pipe inlet to prevent small children or animals from entering.
4 Install a non-perforated plastic main and outlet pipe.

FIG. 8E

Inspect pipe outlets. Look for bank erosion and take measures to correct and prevent further loss.


OUTLET MAINTENANCE

4 Keep all subsurface drainage outlets clean and in good condition – otherwise the drainage
system cannot function properly.
4 Inspect outlets in spring and fall, and after severe storms to check for silting, debris,
erosion, settlement and misalignment. All problems should be corrected immediately.
4 Ensure that the watercourse into which the outlet empties is maintained in an efficient
working condition. Weeds, tall grass, brush, old fences, fallen trees, and any other debris
should be removed. Otherwise, the water flow is slowed down, causing siltation and
possible submergence of the subsurface outlet. Check culverts or bridges downstream for
8.07p possible blockage and water backup.
4 Contact the Ministry of Natural Resources for approvals before doing any construction
work along a stream or streambank, e.g., installing a subsurface outlet pipe.

TEChNIqUES TO IMPROVE OUTFLOW qUALITy

Note: most outflow conditioning technologies are still being developed, and are not yet
Inspect pipe outlets. proven BMPs for agricultural applications.
Look for bank erosion
Monitoring may show that outflow quality is in need of improvement.
and take measures to
correct and prevent Preventive measures are better than remedial measures. Most drainage professionals will
further loss. promote the idea that preventing contaminants from entering drainage systems is more
effective than conditioning pipe outflow. Check the chapter on BMPs for Soil Management
and Crop Input.
However, the risk remains that
contaminants could reach the outlets
– especially when the choice of 8.08p
preventative BMPs prove to be ineffective
for local site conditions or when storm
events override the system.
In these cases, “end-of-pipe”
conditioning systems may serve as
a backup level of protection. Some
may include containment to handle
large outflows following storm events,
snowmelt or whenever there is
significant flow. Generally, it’s easier to
improve water quality at times of low
flow – and much harder for medium to Muddy outflow is most often tied to periods of
high flows. This is why containment is high flow, which are hard to manage. For BMPs
required for any end-of-pipe technique. on this, see page XX for BMPs that will reduce
sediment, pathogens, nutrients, and other potential
contaminants in outflow.


Preventative BMPs are best to reduce contaminant loading from
subsurface drainage systems. Drainage or communal channels
can also improve drainage water quality. The nature and extent
of this function increases as channels assume natural features,
and decreases with increasing disturbance (e.g. clean-outs).
See the next chapter, BMPs for Communal Drainage for more
information.

CONDITIONING PROCESSES

Physical/Chemical Conditioning
Sediment removal
� soil-attached nutrients, pesticides and pathogens can be removed by sedimentation,
flotation, centrifugation, and filtration with devices such as sediment traps
� the process of removing soluble contaminants by attachment to a solid
e.g., the removal of soluble organic compounds such as pesticides via adsorption
onto granular-activated carbon or the surface of vegetation
Biological Conditioning
Biological conditioning usually refers to the use of bacteria suited to aerobic or anaerobic
conditions in engineered reactor systems. The purpose is to remove or change inorganic and
organic compounds, trace elements and nutrients.

EMERGING TEChNOLOGIES

There are several types of technologies that show promise for conditioning drainage outflow:
� stormwater technology
� constructed wetlands
� dispersion Sandwich.
Stormwater Technology 8.09p

A detention basin is an impoundment
that collects outflow from the highways
via storm drain inlets. It captures and
detains the designed water quality runoff
volume (typically for 48 hours) prior to
discharge, typically through a perforated
riser. It removes floatable debris and
coarse suspended solids. Pollutant removal
is achieved primarily through settling
of sediments and particulate forms of
pollutants.


8.10p 8.11p

Vegetated swales are vegetated areas, similar Filter strips are relatively flat, vegetated areas that
to grassed waterways that accept concentrated accept sheet flow from runoff and use filtration and
flow from runoff via storm drain inlets. infiltration as removal mechanisms.
Physical processes of filtration and infiltration
are employed as water flows through the
vegetation.

PHOTO TO COME

“Farmers should continue to 8.12p
follow the best management
practices needed to ensure the
highest quality of drainage
water.” Ron Fleming, Ridgetown
Campus, University of Guelph

Constructed Wetlands
8.13p
Wetlands can reduce some pollutants such as
nitrogen (N), phosphorus (P) and sediment,
and improve water quality. Evaporation from
wetland surfaces and transpiration from wetland
vegetation will reduce standing water volumes.


Fig. 8F

Natural wetlands are recognized for their ecological role in filtration, habitat and groundwater
restoration. Constructed wetlands have similar benefits to the environment, and are being explored as a
mechanism to treat wastewater from livestock farms and agricultural drainage.

Flow-through wetlands are one option for the management of agricultural drainage
water. They are constructed wetlands or natural depressional areas that make possible the
movement of surface waters through specially selected vegetation.

Fig. 8G
Flow-through wetlands can improve
drainage water quality, providing:
• hysical filtration and
p
sedimentation of soil particles and
attached contaminants
• egetation to remove excess N, P,
v
K and organic wastes
• reeding, nesting, feeding and
b
cover habitats for invertebrates,
insects amphibians, reptiles, birds
and mammals.

A dispersion sandwich is a denitrification reactor that uses alternate
layers of fine and coarse wood particles aimed at maintenance-free
nitrate removal (up to 25%) in agricultural subsurface drainage.
They are most usefully applied in the treatment of baseflows rather
than peak flows.va


BMPs FOR COMMUNAL DRAINAGE

A communal drainage system is one that has been
constructed through a public body such as a municipality
or road authority, or through the cooperation of a group
of landowners. Many of the responsibilities fall to drain-
age professionals, but the processes involved should be of
interest to anyone involved in agricultural drainage. In this 9.01p
chapter, we will focus on BMPs for planning, constructing
and maintaining communal drainage channels. You’ll also
find information on creating and maintaining healthy ditch
banks and buffer strips.

Communal drainage components are in
the form of open channels or buried large-
diameter pipes. These drains are often
called municipal, mutual agreement, award
(old term), or private drains.

PLANNING COMMUNAL DRAINAGE PROJECTS

If you’re a communal drainage professional / engineer, begin by determining the feasibility
of the project. Your investigation should provide a clear understanding of the problem, the
types and degree of needed, and an estimate of the cost and expected benefits and impacts
of the project. This information can often be obtained from a reconnaissance of a small
problem area.
More detailed examinations and surveys are made where the size of the area, lack of
defined drainage pattern, or such special situations as riparian vegetation, wetlands, or
rock outcrops exist. Environmental considerations must be a part of the planning process –
including habitat enhancement or mitigation where needed. You should hire a professional
to do this work, and ensure proper procedures are followed.

B E S T M A N A G E M E N T P R A C T I C E S � B M P s for C O M M U N A L D R A I N A G E 1 6 5

STEPS USED BY DRAINAGE PROFESSIONALS TO PLAN A COMMUNAL DRAINAGE SYSTEM

STEP EXAMPLES OF INFORMATION NEEDED SIGNIFICANCE

1. Reconnaissance • location of legal outlet • orientation to situation
• soil types and aerial extent • determine next steps
• field verification of soils and outlets • may determine if the project
• observations about drainage problems in surrounding area should proceed
• history of problem from landowner
• fish habitat information

2. Problem verification • condition of existing agricultural drainage system • not all drainage problems
• reasons for inadequacy require communal drainage
• nature and extent of drainage problem work
• feasibility of channel as benefit to neighbour

3. Site survey • size and ownership of the area being considered for drainage • if problem requires water
• location and condition of the legal drainage outlet management and drainage
• location, condition, and approximate size of existing work – this step scopes out
waterways plus high-water marks or damaging floods and the nature and extent of the
dates of floods problem and other
• location of and assessment of potential impact of project challenges for system
on utilities selection and design
• sources of excess water from upslope land or from flooding
• surface runoff and erosion control requirements
• estimate of surveys needed including topographic elevations

4. Soil survey • description and areal extent (acreage) of key soil types • verifies areas requiring
• soils information – texture, drainage, depth of area drainage
requiring drainage work • elps with systems sizing
h
and special drainage
features – e.g., envelopes

5. Topographic elevation • elevations and benchmarks • detailed information
survey • depth of outlet required for design and
• slopes installation
• aerial estimates • ocation, spacing, depth
l
and size of pipe

6. Watershed sizing • topographic and detailed physical survey to size watershed • required information for
proper design – sizing,
outlets, etc.
• inadequate information
could cause system failure
or local flooding

7. Suitable outlet • information to verify suitability of nearest outlets • proper functioning of the
entire drainage system


STEPS USED By DRAINAGE PROFESSIONALS TO PLAN A COMMUNAL DRAINAGE SySTEM

STEP EXAMPLES OF INFORMATION NEEDED SIGNIFICANCE

8. Environmental • identification and consideration of local natural areas – • prevents off-site habitat
considerations ponds, wetlands, surface waters with designated fisheries, and water quality damage
ESA or ANSI designation
• precautions identified to address water risks to drainage
outflow quality

9. Options and costs • drainage system choice and detailed design features • this steps embraces all
• drainage management options and costs to help with technical, environmental
decisions management , regulatory
and economic information
to help landowner make
best business decision

10. Approvals and funding • compliance with any regulatory or municipal bylaw • approvals may be required
requirements are met (e.g., proper outlet, protection of before work can proceed
wetlands and habitat) and before cost-share
• information required for project funding funding can be accessed

9.02p 9.03p

identify utilities and potential impacts

describe action and significance

9.04p
9.05p

environmental and habitat considerations importance of proper outlet + other
approvals

B E S T M A N A G E M E N T P R A C T I C E S � B M P s F O R C O M M U N A L D R A I N A G E 1 6 7

Most municipal drains constructed under the Drainage Act are either open drains (ditches)
or closed drains (large-diameter drainpipe). They can also include structures such as dikes
or berms, pumping stations, buffer strips, grassed waterways, stormwater
detention ponds, culverts and bridges. Some creeks and small rivers have PHOTO TO COME
been incorporated as municipal drains.
9.06p
To minimize the potential negative impacts on natural watercourses,
sometimes a natural watercourse is incorporated as a municipal drain
strictly for the purpose of removing beaver dams and other obstructions. No
channelization work is involved.
A municipal drain can also include a water control structure. Some water
control structures are being fitted into existing municipal drains for the
purpose of retaining water and even restoring or enhancing wetlands. [For
more info, see wetland drain restoration project, page XX.]
Some large rivers
DESIGNING A NEW OR IMPROVED CONSTRUCTED DRAIN PROJECT such as the South
Branch of the Nation,
If this is a big enough project, there are many factors for drainage professionals to consider. and portions of the
Raisin and Saugeen
Design Considerations are channels under
the Drainage Act.
The design should consider the following: 9.07p
� order: peak flow, flooding, scouring, low-
level flow, etc.
� peak-flow rates in outlet watercourse that
won’t be increased from pre-construction 9.08p
conditions after the project is completed
� ability to handle volume and flow-rate
capacity of a 1 in 2-year design storm
frequency
� prevention of increased flooding downstream
� flood control measures downstream where 9.09p
warranted.
� minimal ditch-bank scouring and slumping
� effective sediment transport
� low-level flow that allows outlets to discharge
� prevention of soil saturation and flooding. Closed communal
drains are often
constructed with
oversized pipe to
accommodate future
additions to the
acreage outlet.


Hydraulic Design: Hydraulic Grade Line
The hydraulic grade line is the actual water surface profile in the designed channel at the
design flow. The first step is to determine the highest allowable hydraulic grade line.
Control points are established to drain cropland, allow for surface runoff from surface
drainage features, as well as elevations of bridges, culverts and roads. The maximum
hydraulic grade line is drawn through or below as many control points as possible to
minimize flooding

Fig. 9A

Bottom Grade and Depth of Ditch
The ditch bottom should be deep enough to allow outlets to discharge above the low-flow
elevation: 0.3–0.5 metre (1–1.6 ft) above the ditch bottom. Also:
� m
inimum depth for ditches with outlets is 1.5 m (5 ft) [Fig. 9B (was 5.R illustration
x-section of ditch]
� ufficient
s depth is provided for some sediment build-up – this will prevent early
sedimentation as an obstacle to flow
t
arget to have sufficient depth so that the outlet pipe is at or above normal flow of
water – preferably 0.3 m (1 ft) above
� rades
g and depths of pipe from the lowest drainable depression in the watershed to
the outlet for the drainage channel must be aligned to determine minimum ditch depth
throughout the project.


Fig. 9B

Side Slopes
Bank slopes are designed to maintain flow and resist degradation from erosion, scouring and
slumping.
Fig. 9C
Banks are sloped with specifications
(horizontal: vertical) based on soil 3m 1m
materials and the presence of bank 1m Slope
protection BMPs, such as buffer strips, Buffer
managed bank vegetation, and fencing 1:1
Channel
and revetment (armour, gabion basket).
Ditches in clay soils with protection can
be as steep as 1:1, but generally side 3m
slopes steeper than 2:1 are used. Side 2m
slopes for unstable and unprotected soils 1m
(e.g., bare, wet silty soils) may need to
2:1
be as flat as 4:1.
Bottom Width
Two-staged or bench-drain bottom 3m
3m
designs are recommended to handle low-
flow and peak-flow conditions. 1m

A narrow 60 cm (2 ft) channel 3:1
is constructed to handle low-flow
conditions within a 2–3 metre (6.5–10
ft) vegetated drain bottom or floodplain
3m
that can withstand high-flow conditions. 4m
1m

4:1


Fig. 9D

Fig. 9E


CONSTRUCTING COMMUNAL DRAINAGE ChANNELS

During ditch construction, the potential risk to the environment is greater. Sediment from
excavation, bare banks, and adjacent lands can become deposited in the channel, impairing
water quality and habitat. Drainage professionals and contractors must ensure that sediment
control is addressed in the timing, planning and construction of the drainage channel.
4 Schedule drain construction or improvement work during the summer following the
harvest of cereals in rotation to reduce sedimentation and habitat disturbance. per Don
Lobb, cross-ref w/Timing of Maintenance Activities]
After considering downstream impacts, select one or more of the following BMPs that suit
your circumstances.
Buffer strips keep agricultural activities and water separated. They reduce the need
for clean-out maintenance of drains They can also reduce runoff, filter contaminants,
act as windbreaks, be harvested as forage, provide shade (which in turn cools water
temperatures), and provide habitat for a variety of species.
Long-Term Protection
4 Establish buffer strips (for more
information, see pages XX–XX). Consult Be cautious. With buffer strips, build it and they will come. The
with your local Conservation Authority issue of wildlife predation may have to be addressed.
or Ministry of Natural Resources office
to identify the most appropriate timing
window for construction, to protect fish and
wildlife.
Short-Term During Construction 9.10p
4 Use mulching and silt (turbidity) fences:
� mulching can provide temporary protection of ditch banks from erosion
during or immediately following construction
�a wide range of natural and synthetic mulching materials is available
� seed–mulch mixes used in road construction are also effective
� turbidity fence and rock check dams.


4 Establish vegetative cover:
� bare soils on banks and near channels can 9.11p
lead to erosion and sedimentation
� vegetative cover will keep soils in place
� specialseed mixtures and nurse-crop
combinations have been developed for
construction and erosion control
� timingis critical to encourage seed
germination
ensure there is adequate moisture and sufficient temperatures for
germination of growth – seed banks within 24 hours of excavation, when
soil surface is still rough (to capture seed) and has some moisture
avoid seeding too early, too late, and too dry
combine with mulch to secure the site and to increase germination rates.

MAINTAINING DRAINAGE ChANNELS
9.12p
Open drains need maintenance when their ability to move water is impaired. This usually
results from filling in with sediment and debris due to one or more of the following:
� erosion of topsoil from adjacent fields
� cropping too close to drainage channel
� poor drain design – inability of channel to transport sediments out of system
Livestock should
be excluded from � excessive growth of vegetation along banks
drainage ditches.
� excessive slumping and erosion along banks caused by too-steep banks, lack of bank
Exclusion can be
accomplished by vegetation, or livestock/machinery access
permanent fencing or � failure of outlet structures
temporary fencing as
part of an intensive � failure of upstream drainage systems.
grazing management
system. See the BMP Excavation during maintenance can destroy fish, their eggs, and amphibians. Habitats for
book Streamside many species, including aquatic insects that fish feed on, can be wiped out. Traditional
Grazing. maintenance can also reduce habitat diversity by eliminating pools, riffles, and overhanging
banks. Water depth may be lowered, and sediment loads could be temporarily increased,
which harms habitat quality.
Bottom cleanouts will reduce sediment in the bed of the channel without disturbing the
banks and bank vegetation. BMPs for drain maintenance will reduce impact. A full channel
excavation is usually only done to increase side slope for longer-term benefit. As with drain
construction, these too should be seeded immediately to reduce impacts.


Sediment, excessive vegetation,
and woody debris at the bottom
9.13p of the channel may obstruct flow
excessively. Remove it during the
early part of the growing season
(June) where possible to minimize
disturbance. Bottom cleanouts will
only remove the obstructions in the
channel bed. Bank stability is not
affected. Removed sediment should
be spread well back from the top of
the ditch bank.

Vegetation and crop residue
can block the flow of draining
water during times of high flow. 9.14p
Removing large obstructions can
stabilize the banks. This involves
the judicious removal of woody
vegetation by trimming, pruning
and thinning, or mowing only
heavily grassed areas. Removal from
only one side of the ditch bank may
be all that’s necessary.

Other [open?] drainage channels tend to naturalize over time. The naturalization process
results in:
� changes in the channel’s shape, which increases habitat diversity
� increased plant diversity on the banks
� increased shade and cover provided by bank vegetation
� increased numbers of aquatic plants.
Many species of fish and wildlife that require
clean water and substrates benefit from good
drain maintenance. And remember that When planting trees, take care that the tree species you select
conservation cropping, establishing buffers
will not interfere with future maintenance activities, won’t
between cropped fields and drainage channels,
drop undue debris, and that trees comply with engineer’s
and planting shade trees along drainage
channels will go a long way to reducing future report if it’s a municipal drain.
drain maintenance requirements and improving
habitats for a range of species.


Check with your local drainage superintendent and Conservation Authority before taking
any action around drains as described in the following charts.

PHOTO TO COME
9.15p

When cropland drainage systems in a watershed are not
contributing flow, the wider and deeper (“improved”) natural
watercourses perform poorly at cycling natural baseflow. At these
times, flow may stop or become stagnant, and this will cause
water quality to deteriorate to the point no one can use the water.
Furthermore, during low-flow periods, the oversized natural
channel will become choked with sediment. The lack of a flushing
flow will allow vegetation to take over – again impeding flow.
When the cropland drainage system next delivers flow, flooding
and other property damage is very likely to occur if the channel
has not already been cleared.

Municipal drains are the responsibility of the local municipality. If the drain is in disrepair, contact the munici-
pal drainage superintendent to confirm whether the outlet is indeed a municipal drain, and discuss the prob-
lem. If it is a municipal drain in disrepair, it is the municipality’s duty to repair it. You must give formal notice
in writing to the clerk that the drain is in disrepair.

The cost of the maintenance will be spread over the drainage area according to the last applicable drain bylaw,
and will usually be collected by the municipality. If the drain is old and the land use in the area has changed, it
may be better to petition for a new assessment.

If the outlet is an old award drain or an agreement drain, maintenance must be secured through an agreement
or a court order. See OMAFRA Factsheet, Drainage Legislation, Agdex 752.


BMP HOW IT WORKS BENEFITS MAKING IT WORK

4 Selectively remove excess • excess bank vegetation • decreased maintenance costs • retain trees wherever
bank vegetation – remove (where high density causes • stable banks possible
some vegetation so that wind throw and breakage) • vegetation provides habitat • remove cuttings to prevent
channel remains functional can reduce drain’s ability for various wildlife and downstream damming
to move water and can insects and fish • minimize removal of
hinder maintenance • fish species that require vegetation by confining
• vegetation helps keep water clear water and clean operations to one side only,
cool, stabilizes banks and substrates if possible
provides habitat for many • don’t use herbicides to
species control or eliminate bank
• bank vegetation helps to vegetation – they destroy
remove nitrates from habitat, may harm some
groundwater and filters wildlife, and present water
sediments from surface quality risks
water –selective removal • avoid exposing bare soil
may be required to allow
machinery access or to
improve flows

• Revegetate bare banks – • vegetation helps to • reduced erosion leads to • use bioengineering
establishment of vegetation stabilize banks decreased maintenance techniques to establish
along banks of ditched and • shrubs don’t restrict access costs and stable banks woody vegetation on
channels by heavy equipment (like • vegetation provides habitat unstable banks
trees can), and they provide for various wildlife and • use erosion control mats
excellent habitat for wildlife insects and fish and erosion control seed
• native grasses are more • fish species that require mixtures to establish grass
difficult to establish than clear water and clean cover
tame grasses, but last longer substrates • seed in fall for adequate
and provide better habitat moisture conditions and
lower risks of scouring

4 Install sediment (sand) • trapping sediments will • sediment traps will decrease • require regular maintenance
traps – creation of reduce the amount long-term maintenance costs to ensure effectiveness
excavated depressions in transported downstream • aquatic species that require • can be included as part of
the channel bottom that • can reduce future clear water and clean an engineer’s report on
trap sediments maintenance requirements substrates municipal drain projects
and costs •feeding and rearing pools • ensure they don’t destroy
• maintenance efforts can be for fish, and helps maintain critical fish habitats
concentrated around habitat in other portions of • use in sandy soils and use
sediment traps reducing the the watercourse to trap sediment stirred up
need to maintain entire during cleanouts
drains


BMP HOW IT WORKS BENEFITS MAKING IT WORK

4 Time maintenance • early season maintenance • properly timed maintenance • do maintenance early in the
activities – schedule will help disturbed bank can decrease costs growing season to allow
drainage work to maximize vegetation re-establish • all fish and wildlife species, more time for regrowth of
effectiveness while • alternatively, maintaining if maintenance is well-timed vegetation
minimizing impact on drains when water flow is [per Don Lobb, cross-ref w/
drain habitat low will disturb less Timing of Maintenance
vegetation, banks and Activities]
habitat • do it in as short a period
• there are critical periods in as possible
the year for spawning, • maintain drains when flows
nesting and hibernation – are low
avoiding these times will • avoid critical times for fish,
help with species survival amphibians, birds and
reptiles

4 Remove debris and excess • excess debris/ vegetation • improved drain function • remove debris and
vegetation from bottom of on drain bottom can • less sediment buildup and vegetation if heavy siltation
drainage channel – obstruct flow, trap sediment reduced need for drain exists and flushing are
manual or mechanical and create barriers to fish maintenance required
removal of vegetation and • fish species requiring clean • create a two-stage channel:
debris from channel bed substrates and barrier-free excavate or cut a narrow
mobility c
hannel through bottom
vegetation (especially
cattails); water flow may be
sufficient to keep open

4 Perform bottom cleanout • most obstacles to flow and • increased efficiency of • practise good sediment
vs full drain cleanout – drain function are in the cleanout work control techniques during
excavate or cut a narrow bottom of the channel • less excavated material to cleanout
channel through • restricting cleanouts to the manage • incorporate natural-channel
vegetation and sediment drain bottom will allow: • reduced fossil fuel features into drains during
at bottom of drain water to flow, undisturbed consumption bottom cleanouts to benefit
bank vegetation to • many fish and wildlife fish and reduce erosion/
assimilate nutrients and species, because bottom sedimentation and bank
sediment, and aquatic cleanouts provide superior failures
habitats to function with protection of habitats than
minimal disturbance full drain cleanouts


BMP hOW IT WORKS BENEFITS MAKING IT WORK

4 Relocate soil properly – • excavated sediment, • reduced frequency of • deposit on dry land, and
distribute cleanout spoils vegetation and debris can cleanouts spread and stabilize with
to minimize impact on wash back into channel, • less interference with field vegetation as soon as
adjacent cropland and cause flooding on adjacent operations on adjacent practical
drainage channel function fields and interfere with cropland • start spreading at least 3 m
riparian traffic • less interference with field (10 ft) from the bank
• there are 3 operating operations on adjacent • ideally place at least 3 m
principles to consider: cropland (10 f) back from the bank,
• weight distribution • aquatic species that require and spread and stabilize
and bank stability clear water and clean with vegetation as soon as
• cost and inconvenience substrates possible
of wide distribution • spread as thinly as possible
• obstacles to runoff (i.e., to avoid affecting seedbed
bermed spoils) will require characteristics
surface outlet (e.g. rock
chute spillway)

PHOTO TO COME
9.17p 9.18p

Sediment may be flushed from gravel bottom
by narrowing the channel to speed up the
current.
Spread material according to drainage report. 2 inches
thick over 100 ft – cause less problems. Spread as thinly PHOTO TO COME
as possible to minimize surface flow back to the channel if
it’s a non-engineered drain 9.19p


BEAVER DAM REMOVAL

Beaver dams need to be removed or breached periodically to avoid the flooding of private
and public land. Removal is normally handled by professionals and is accomplished using
hand tools or equipment such as backhoes. However, the removal of beaver dams can have
a negative impact on fish and fish habitat and on downstream flows. Consider impacts on
hibernating animals.
4 Before undertaking this work, notify your local Conservation Authority or Fisheries and
Ocean Canada office. For more information, see the “Beaver Dam Removal” operational
statement produced by Fisheries and Oceans Canada.
4 Beaver bafflers and similar techniques that maintain the dam but lower ponds and
maintain flow are not recommended for municipal drains.
4 Hire a licensed trapper to remove beaver. Consider live trapping and release.
For more information, see the recent guidelines on drain maintenance developed by the
Ministry of Natural Resources, OMAFRA, and the Drainage Superintendents Association of
Ontario. (MNR Guide to Understand and Coping with Beaver Activities” FG-006.) [insert
reference]

The key BMPs for beaver removal
include contacting the proper
9.20p authorities and, where appropriate,
hiring a professional to handle the task.
This approach will reduce the risk of
causing damage downstream.

BMPS FOR DITCh BANKS AND BUFFER STRIPS

Some ditch banks are subject to slumping, scouring, and other forms of bank erosion.
Observe the integrity of ditch banks seasonally, and take timely action when need so as to
reduce downstream sedimentation and early drain cleanout maintenance.
Before you start
4 Verify the problem. Determine the type of bank 9.21p
erosion, e.g., stream or subsurface flow. Decide
what’s caused the erosion.

Inspect the integrity of on-farm and
communal ditch banks each spring and
after severe rainfall events.


4 Get technical assistance from your Drainage Superintendent, Conservation Authority or
the Ministry of Natural Resources. They can help you assess the situation and discuss
9.22p
BMP options. Some groups may offer financial assistance.
4 Talk to your neighbours. You may share a problem, and perhaps a project. At the very
least, share your views.
4 Look into local habitat or environmental group initiatives. Volunteers can make a
difference.
4 Get the necessary permits and approvals. Don’t let a missed step ruin your good
intentions.
4 Use local natural materials and native or non-invasive plants wherever possible. Select
the most suitable species for the job.
4 Once you’ve started, install sediment control features, e.g., coffer dams, erosion control PHOTO TO COME
blankets, bales. 9.23p
4 When the project is completed:
� restrict access to plantings during establishment
� water plants during droughts
� control weeds until your plants are established
� monitor the site and make adjustments.
Coffer dams in the
REShAPING BANKS South Nation River
reduce sediment
4 Shape ditch banks to prevent erosion and disturbance.
provide bank stability. 9.25p
In general, 2:1 slopes are recommended for most
soil types. Consider 1.5 horizontal to 1.0 vertical 9.24p
as the absolute steepest slope, with 2.0 to 1.0
preferred normal slope.
An important advantage of the flatter slope,
other than stability, is that it’s easier to get
vegetation established on the banks.
Note: the risk of erosion, sedimentation and
negative habitat impacts can be reduced by staging (planning at different times) drainage
channel works. This will leave pockets of habitat undisturbed. Use silt fences or
other fish-friendly
4 Establish vegetative cover (after reshaping) as soon as possible on the bare ditch bank. measures for working
on banks while doing
A proven method of seed establishment is called “daily seeding,” which simply means that
work in streams.
a section of ditch constructed on a specific day is seeded the same day. This can be easily
achieved with a hand-operated cyclone seeder. The main reason for the success of this Disturb only when
method is that a newly cut bank will normally provide enough moisture and roughness / necessary: soil and
loose soil to allow the seed to establish. plants in place are
already stable. Don’t
In sensitive areas, where faster or more guaranteed seed establishment is required, you may use invasive species
consider doing special application of materials, e.g., straw mulch, hydro-seeding, erosion or wood treated with
control mats. preservatives.


Remember that all ditches are connected
to a downstream watercourse. Consult
the drainage superintendent and ensure 9.26p
you get the proper permits before
proceeding.

ChANNEL CROSSINGS

Crossings can be for livestock or machinery, and should not cause damage to drainage
channel features. They should be designed to reduce livestock access
Poorly designed equipment or livestock crossings can impede channel flow, obstruct fish
movement in flowing waters, and limit navigation by small watercraft.
Check with regulatory authorities to obtain approvals before creating any type of crossing
structure. Start with your local drainage superintendent, Conservation Authority or Ministry
of Natural Resources (MNR) office. Remember too that for work in and around water, you
may require assistance from an engineer or other professional.
4 Embed culvert crossings at least 10% of diameter.

FIG. 9F

4 Ensure water velocities do not impede fish movement.


FEATURE –
TyPE DESCRIPTION ESTABLIShMENT TIPS ADVANTAGES DISADVANTAGES

MID-LEVEL • culverts and concrete • check with Drainage • permanent • relatively high cost
CROSSING WITH are used to construct Superintendent, federal • dry crossing for most • can cause flooding
FULL-FLOW these bridge-like Dept. of Fisheries, local of the year – requires upstream
CULVERTS crossings at mid-bank Conservation Authority, approval • poorly designed mid-
level MNR and municipality • will convey water from level crossings can
• culverts are usually • approvals are required most storm events obstruct flow during
placed at bed-level from the various through culverts periods of low water
(embedded to at least agencies for work in
10–15% diameter) and around water
• may be suitable for • key features include:
narrow-channel drains full-flow culverts; gated
entrances to control
livestock access;
erosion-resistant
materials on entrance-
way surfaces

BED-LEVEL • crossing is established • check with drainage • permanent • should be gated and
CROSSING at watercourse superintendent, federal • moderate cost part of rotational
bed-level department of Fisheries • no negative impact on grazing system to be
• materials used are and Oceans, and local water flow if built effective
concrete slats, coarse Conservation Authority properly • livestock still have
angular stone, and or MNR impact while crossing
other prefabricated • approvals may be • If not sited or built
materials suitable for required from the correct can have a
wide-channel drains various agencies for negative impact on fish
work in and around and fish habitat
water • Improperly located or
established bed-level
crossings can cause
negative impact on
fish movement

9.27p

Bridge crossings must be designed by a
professional engineer.


BANK EROSION CONTROL STRUCTURES

These projects typically involve hard materials such as rock, concrete and wood being
anchored to a bank to protect it from erosion (e.g., crib walls, rock riprap). Hard techniques
provide a solid defence against the energy of flowing water, particularly at the “toe” of the
slope where erosive energy is greatest.
Hard structures are suitable for open drains and channelized watercourses. Some of these
9.28p techniques are shown in the accompanying photographs. They must be placed flush with
the ditch bank, so as not to create an obstruction during high flows.
4 Rock riprap. Rock riprap is a hard erosion control structure for banks where angular
rocks and boulders are strategically placed at 60 cm (2 ft) horizontal for every 30 cm (1
ft) vertical rise, or flatter slopes to protect bank soil materials. The structure should be
underlain with filter cloth. Rock riprap is most suited to local spots of extreme erosion.
It may not be suitable for sandy areas or areas with significant subsurface flow. In
these areas, soil materials can be washed from beneath the rock, causing failure and
severe erosion. These structures are best used in combination with plant bioengineering
techniques.
9.29p 4 Riffles and pools. Streambeds are deepened to create pools. Coarse materials are placed in
beds to create riffles.

SOIL BIOENGINEERING

Bioengineering
Soil bioengineering involves the use of living and dead plant materials to restabilize eroding
soil materials in banks (e.g., live fascine or brush mattresses) and is often referred to as soft
erosion-control structures.
When combined with live plant materials, rocks, logs and roots will hold soil, slow water,
filter contaminants, and grow to provide habitat. Several techniques are described below.

9.30p 9.30p

4 Brush layers. Bundles of live cuttings are
4 Live staking. Live, rootable cuttings are set at right angles of slopes to break up
planted along eroded banks of small slope length and create a living root mass.
streams to create a living root mass that See BMP book, Fish and Wildlife habitat
will stabilize and bind the soil. Management.


You could also strategically place tree stumps to stabilize the outside bends of watercourses
until other living vegetation establishes itself. Be sure that the stumps are well-anchored, or
they’ll become dislodged and cause problems downstream.
Drop Structures
As we’ve noted several times, consult your local drainage superintendent and Conservation
Authority before taking any action around municipal drains.
One of the major causes of ditch bank failure and washouts is concentrated surface flow
entering the ditch over the ditch bank. Here are three common methods to control this
problem. Drop structures require proper design to ensure proper sizing and structural
integrity.

9.35p
9.34p

4 Drop pipe inlets. Placed at the edge of
fields near ditches and other watercourses,
4 Rock chute spillways. These spillways are sloped drop pipe inlets drop concentrated flow and
riprap structures placed at points of entry for ponded waters safely to watercourses. Pipe
surface runoff from cropland that’s level or designs can be steel, plastic or concrete.
gently sloping. They have to be wide and deep
enough to adequately carry the surface flow and
should extend from well into the field to below
9.36p
the level of flowing water. Rock chute spillways
prevent ditchbank failure caused by scouring.

9.37p

4 WaSCoBs (Water and Sediment Control Basins).
WaSCoBs are earthen berms constructed
strategically located across a low draw in the
field with the function of ponding runoff water.
4 Gabion baskets. These involve rock materials held They prevent gully erosion by intercepting
in place with wire cages. Filter cloth must be used concentrated flow and creating temporary
underneath the structure. They are suitable in ponding conditions behind an earthen dam or
areas with local spots of extreme erosion, used berm. Ponded water is slowly released through
either on their own or in combination with other a drop inlet to a proper subsurface inlet. They
hard structures such as bridges and crossings. In are designed so that ponded water is slowly
other situations, gabion baskets may be considered released over a 24-hour period in a drop inlet.
in combination with plant bioengineering.


BUFFER STRIPS

Buffer strips come in all shapes and sizes, and for good reason. Wider buffers are
advantageous for wildlife habitats, whereas narrow buffers are perfectly adequate for simple
setbacks from cropland. Local site conditions also affect buffer strip design. Wider buffers are
more effective for runoff and erosion control on steeply sloping lands.,
Generally speaking:
4 grassed buffers should be at least 3 metres (10 ft), wide but 5 metres is more effective
[see BMP Buffer Strips]
4 consider designs that serve multiple uses: e.g., erosion control, filters for runoff, wildlife
habitat, biodiversity, field access and forestry
4 municipal drains can be treed – but preferably
on south and west side – assuming 9.38p
accommodation has been made for
maintenance
� check Drainage Report for tree
planting details
� thedrainage superintendent must
be consulted and approval obtained
before altering or replanting
4 drop structures and berms may be
appropriate where field runoff regularly flows
in a draw before it reaches the ditch. Routinely inspect buffers strips along drains
and other outlets. Look for areas where
4 Plan and implement the most suitable design concentrated overland flow has bypassed your
to meet the desired functions for the riparian buffers (e.g., for “short-circuiting” overland
condition and your preferences. This is key to flow).
a successful riparian buffer.
Buffer strips can be planted to grass, wildflowers, shrubs and trees.
4 Select plants according to the desired buffer function and also the plants’ suitability to
local site conditions, including climate, soil, soil drainage, soil pH and risk of flooding.
Avoid invasive, non-native species, wherever possible.
Plants can be established in many arrangements and mixtures to suit design needs. Suitable
species for buffer strip plantings are grouped and listed below.


Grasses
4 Look for grasses that have as many of the following features as possible:
� dense branching

Fig. 9g

Switch Grass Orchard Grass

� pright
u stems that remain erect in winter to trap sediment in runoff and offer superior
waterfowl nesting
� strong, deep rooting systems and/or that are drought-tolerant
� match local soil and site conditions
� usefulness for harvesting forage.
Trees and Shrubs for Buffer Strips
4 Base your selection of trees and shrubs for buffer strip plantings on the following criteria:
� climate – think globally and plant locally by using plants suited to the region
� soil drainage – promote survival and growth by matching trees to site conditions
� flood tolerance – ensure any trees in floodplains are flood-tolerant
� hade
s tolerance – ensure slower growing trees and shrubs, or ones that are likely
to be in the shade for most of their existence, are shade-tolerant
� rowth
g rate – plant fast-growing native or non-invasive trees if you need to create
shade as soon as possible
� ildlife
w value – determine which trees are best suited to providing cover, shelter
and food


� use diverse number of species – avoid monocultures
� economic value – be aware of the most valuable trees to grow
� f
i planting shrubs on the side of the channel that will be used for maintenance,
ensure they’re hardy enough to withstand possible machine damage.
Check with the local drainage superintendent and Conservation Authority to ensure the
suitability of the project and species selected.
How to Establish a Buffer Strip Project
The most effective buffer strip projects are planned. Here are some planning considerations:
Step #1 Assess existing conditions in your riparian area(s) – e.g., in-stream
conditions, water quality, and vegetation quality. Draw map showing soil types,
Fig. 9H

Woodlot

Cropland

Slope Buffer

Wetland Area
Stream and Drainage ditch
Wet area in
floodplain
spring

slopes, existing vegetation, adjacent croplands, and other riparian and natural
areas. Complete a Grazing Management Plan if appropriate.
Step #2 Predict the benefits of a well-maintained, planted buffer strip. Put your list of
desired benefits together with other related management goals and objectives.
Consult your Conservation Authority to discuss risk assessment and identify
opportunities. Select multiple functions for the buffer strips. Talk to neighbours.
Step #3 Assess upslope conditions on the farm. Ask yourself whether additional soil and
water conservation BMPs would enhance the effectiveness of your buffer strip(s).
Step #4 Examine and select options. Which BMPs will do the job? Do the advantages
outweigh the disadvantages? Which options require approvals, permits
and technical assistance? Which agencies offer financial assistance? If the
watercourse is a municipal drain, prior approval of the drainage superintendent is
required.
Step #5 Design and implement. Seek technical advice from a Conservation Authority and
other agencies and from experienced landowners. Obtain permits and approvals


where necessary. Create an action plan: outline your resources, your
time, and a schedule of activities. Remember that the project can be 9.39p
phased in over several years. [scan of Buffer Strip book. see BMP Buffer
Strips for designs]
Step #6 Maintain, monitor and evaluate. Maintain planted vegetation by
irrigating until plants are have become established.
Confirm survival rates of planted grasses, shrubs and trees. Look for
washouts and rills cutting across buffer strip, as well as sedimentation
building up the buffer strip which may eventually create a berm.
Determine if the project is fulfilling its intended functions. Assess whether
additional BMPs would improve its effectiveness.
Consult with your
FIG. #35
local Conservation
Authority to discuss
risk assessment
and identify
opportunities.

On the left is the “before” sketch. On the right is the planned projects sketch for an on-farm stream bank
area.
Cropland erosion is evident from the sloping field on the left of the stream and bank degradation from
intensive livestock access is noted on the right side of the stream. Soil and water conservation measures
– including a cropland buffer strip – are planned for the sloping field. Intensive grazing management,
fencing and alternate water sources are planned for the streamside grazing area.

Narrow buffer strip
9.41p designs are most suitable
along communal drainage 9.43p
channels.

Wide, shallow and
channelized streams
will become narrower
after buffer strips are
established.


APPENDIX I
LEGAL ASPECTS OF
AGRICULTURAL DRAINAGE
Many relevant pieces of legislation – federal, provincial and municipal – are in place to
help ensure everyone working in or around water is giving due consideration to all users,
including private landowners and the general public, as well as aquatic life.
The following tables – the first for federal laws and the second for provincial laws – list the
most relevant legislation that can directly affect the design, construction and maintenance of
cropland drainage and erosion control structural works, the government agency responsible
for it, and its general purpose. Each table is followed by a brief text description of laws
summarized in the tables.

Federal Legislation

LAW / GUIDELINE GOVERNMENT AGENCY GOAL RELEVANCE TO LANDOWNER

Fisheries Act Fisheries and Oceans and • to protect fish and fisheries • general prohibitions against
Environment Canada habitat discharging pollutants to a
watercourse that would harm fish
CAs have partnership or habitat
agreements with DFO to • general prohibitions against
review projects for impacts stream alterations that would
harm fish habitat

Navigable Waters Transport Canada • to protect the public’s interest • some manmade watercourses can
Protection Act, in navigable waterways be considered navigable
R.S.O. 1970 • approval may be required if a
property owner is proposing to
restrict the channel

Railway Safety Act, Transport Canada • to promote and provide for the • controls how a drainage works will
R.S.O. 1970 safety of the public and be constructed on the lands of a
personnel, and the protection of railroad under the jurisdiction of
property and the environment, in the Canadian Transport Agency
the operation of railways

Species at Risk Act Environment Canada • to protect many aquatic species • any works in or near aquatic
from becoming extinct by habitat areas require approvals
providing for the recovery of and permits
species at risk due to human
activity and ensuring through
sound management that species
of special concern don’t become

B E S T M A N A G E M E N T P R A C T I C E S � L E G A L A S P E C T S O F A G R I C U L T U R A L D R A I N A G E 1 8 9

The information provided in this table and within this document is not to be used by persons with drainage or
water problems as a substitute for competent legal advice. The application of the law usually depends upon the
circumstances of each case and laws may be changed by court decisions or legislation.

Where there are legal obligations, there are potential court actions. These court actions are not restricted to
property owners, and may involve contractors and anyone else providing services of any kind to the parties
directly or indirectly involved.

Various penalties including fines, jail terms, profit-stripping, restitution, restoration orders, forfeiture or license
suspension may be imposed against individuals or corporations convicted under the acts noted in this appen-
dix.

Fisheries Act
The Fisheries Act, R.S.C., 1970, is federal legislation dealing with three fundamental
subject matters – the proper management and control of the fisheries, the conservation and
protection of fish and the protection of fish habitat, and the prevention of pollution.
The federal Fisheries Act, R.S.C., 1970, provides for the protection of fish habitat, which
is defined as “spawning grounds and nursery, rearing, food supply and migration areas on
which fish depend directly and indirectly to carry out their life processes”.
Under the Fisheries Act, R.S.C., 1970, no one may carry out any work or undertaking that
results in the harmful alteration, disruption or destruction (HADD) of fish habitat, unless
authorized by the Minister of Fisheries and Oceans Canada. The Act also states that no one
is permitted to deposit a deleterious (harmful) substance into water containing fish.
When planning a project near water, consider the following:
� will the project affect fish habitat?
� could it affect ground water discharge or recharge areas?
� could there be downstream or upstream effects?
� will sand, gravel or stone be added or removed from the water body?
� is a culvert, dam or bridge to be installed or replaced?
� is a dam or reservoir being created?
Fisheries and Oceans Canada may become aware of a project through a direct request or
through a referral from a provincial agency or other organization. Fisheries and Oceans
Canada will review the information to determine if there is fish habitat affected by the
project.
When considering a project, start by contacting one of the following agencies in the area:
� ontact
c the local Conservation Authority (CA) office if property is in a watershed that has
a CA
� f
i there is no CA in the area – contact the local Ontario Ministry of Natural Resources
(MNR) office
� f
i the property fronts onto the Rideau Canal, Trent-Severn Waterway or other federal lands
– contact the local Parks Canada Agency (PCA) office.


To find out more information about the Fisheries Act, R.S.C. 1970, visit
www.dfo-mpo.gc.ca/oceans-habitat
Species at Risk Act (SARA)
A growing number of wildlife species in Canada face a very real – and in many cases,
immediate – threat of extinction. Some of these species are important to industries such as
Canada’s fisheries. Some of them are the last of their kind in the world. All of them have an
essential role to play in the environments where they live. The Species at Risk Act (SARA),
2002, was created to protect many aquatic species from becoming extinct – including fish,
reptiles, marine mammals and mollusks – in two ways:
� providing for the recovery of species at risk due to human activity
� nsuring
e through sound management that species of special concern don’t become
endangered or threatened.
SARA became law in June 2003, and enforceable in June 2004. It’s important to know
about SARA, when installing a culvert, starting a new dredging operation. It’s the
responsibility of individuals to ensure any projects undertaken comply with SARA. The
process for doing so remains as it always has been. Any works – from marinas to bridges –
must be reviewed by local, provincial or federal authorities and authorized through formal
approvals and permits. Apart from making sure the work is in compliance with the Act,
active steps can be taken to protect the habitat of species at risk.
To find out more about species at risk, contact appropriate municipal, provincial and federal
government representatives, or view the SARA online at www.dfo-mpo.gc.ca

Provincial Legislation


Agricultural Tile OMAFRA • to provide for the licensing of • the Act does not apply to
Drainage Installation contractors engaged in the contractors working under the
Act business of installation of Drainage Act nor to individuals
agricultural drainage systems installing drains on their own
• each contractor, each of their / property with their own equipment
her drainage machines, and each
of their operators must be
licensed
• regulates the quality of work by
licensed drainage contractors

Common Law Provincial Courts • generally, to protect the rights Potential civil liability if:
of the people • blocking or interfering with the
flow in a natural watercourse,
causing damage to others
• ollecting and discharging surface
c
water onto a lower property owner
causing damage




Conservation Administered by MNR; • to manage and conserve natural Conservation Authorities regulate
Authorities Act, responsibilities delivered resources within watershed and require permission for:
R.S.O. 1990 by the local CA jurisdiction • proposed development and
• to ensure that the control of activities in or adjacent any
flooding, erosion, dynamic surface waters (e.g., river or lake),
beaches, pollution or the stream valleys, shorelines,
conservation of land are not hazardous lands and wetlands
affected • proposed modification (e.g.,
• to ensure that development and straightening, diverting) or
land management activities do interfering in any way with the
not have a negative hydrologic existing channel of a watercourse
impact of wetlands or a wetland
• roposed development adjacent
p
to wetlands – this could include
lands 30 m or 120 m from the
wetland boundary, depending on
the individual policy adopted by
the CA

Drainage Act, Local municipality, • to provide landowners with a • can be used to obtain an outlet
R.S.O. 1990 OMAFRA procedure to resolve drainage for subsurface drainage systems
outlet problems through the • costs are shared among property
establishment of communal owners who contribute water or
systems called municipal drains benefit from the drain
• also provides for the subsequent • municipality is responsible for
improvement, repair and future maintenance
maintenance of municipal drains • grants are available towards share
by the municipality of cost assessed on agricultural
land

Endangered Species MNR • to protect species at risk and • some activities on ditches or the
Act, 2007 their habitats, and to promote surrounding land may impact
the recovery of species that are protected species and habitat and
at risk may require approval or
involvement of MNR
• rainage activities should not
d
contravene section 9 (species
protection) or section 10 (habitat
protection) of the ESA 2007

Environmental MOE • to protect Ontario’s land, water, • public sector undertakings that
Assessment Act, and air resources from pollution may include water and flood
R.S.O. 1990 protection works

Environmental MOE • to protect Ontario’s land, water, • contaminants are not allowed to
Protection Act, and air resources from pollution be discharged into the
R.S.O. 1990 environment in excess of
regulatory limits




Fish and Wildlife MNR • governs the hunting and • removal of nuisance beaver and
Conservation Act trapping of wildlife and fish in beaver dams must comply with
the province of Ontario and, the legislation
ultimately, facilitates the
conservation and protection of
wildlife and the environment
they inhabit

Lakes and Rivers MNR • to ensure flow and water level • any work forwarding, holding
Improvement Act characteristics of lakes and rivers back, or diverting water must
are not altered to the point of receive prior approval from MNR
disadvantaging other water users
including fish and wildlife

Municipal Act, MMAH, local municipality • to provide for the organization • landowners are responsible for
S.O. 2001 and operation of Ontario’s knowing about local by-laws and
municipalities; control the types the implications (their
of by-laws that municipalities responsibilities) for drainage
can adopt; regulate health, activities
safety and other matters

Nutrient Management OMAFRA, MOE • to provide for the management • compliant livestock producers are
Act, R.S.O. 2002 of materials containing required to develop and follow
nutrients in ways that will Nutrient Management Plans and
enhance protection of the manage manure according to
natural environment and provide regulatory requirements
a sustainable future for
agricultural operations and rural
development

Ontario Water MOE • to protect the quality and • general prohibitions against
Resources Act, quantity of Ontario’s surface discharging pollutants to surface
R.S.O. 1990 water and groundwater resources water or ground water
• ermits are required for the
p
taking of large amounts of surface
water or groundwater, i.e., for
irrigation

Pesticides Act, MOE • protects surface water and • landowners who wish to purchase
R.S.O. 1990 ground water resources from and apply pesticides must take
damage due to improper use of Grower Pesticide Safety Course
pesticides • egulations are set for pesticide
r
storage, mixing, loading and
application




Planning Act, Local Municipality, MMAH • provides a legislative framework • minimum setbacks may be
R.S.O. 1990 f
or land use planning; establish established between watercourses
Provincial Policy Statements and structures
setting provincial policy for
management of flood plains, the
planning of natural resources
and growth management;
authorize municipalities to
establish Official Plans, zoning
by-laws, site plan control,
interim control by-laws;
temporary use by-laws,
subdivision control

Public Lands Act, MNR • sets out the rules governing the • the beds of most lakes, rivers and
R.S.O. 1990 administration of Crown Land streams are legally provincial
(not under Federal control, e.g., Crown Land in Ontario
national parks, Indian reserves,
canals etc.)

Public Transportation Ministry of Transportation • generally, sets out procedures • landowners will require permission
and Highway and controls for the construction, for proposed drainage work that
Improvement Act, maintenance, drainage, implicates the drainage or normal
R.S.O. 1990 construction / development function of highway corridors
adjacent to highways etc. in
Ontario

Wetlands Policy MMA/ MNR • to protect wetlands • wetlands are protected under the
Statement authority of section 3 of the
Planning Act

MNR – Ontario Ministry of Natural Resources; MOE – Ontario Ministry of the Environment; OMAFRA – Ontario Ministry of
Agriculture, Food and Rural Affairs; CA – Conservation Authority
Drainage Legislation
Profitable returns from farmland depend on effective drainage. A farmer may be convinced
of the need for improved drainage but complications such as getting access to a proper outlet
or securing adequate funding may arise when undertaking such work often delays action.
The provincial government has created laws to assist farmers in carrying out drainage
projects.
The Drainage Act, R.S.O. 1990
Within this act, the three types of procedures established for construction of drains involving
more than one landowner are the mutual agreement, requisition and petition procedures.
Contractors doing work to control soil erosion are encour¬aged to make use of the mutual
agreement when the structure can be defined as a drainage work under the Drainage Act,
R.S.O. 1990, and it requires the cooperation of two or more landowners.


Mutual agreements are recognized to have a limited application and should be reserved for
smaller projects. The limits result from the fact that, although the agreement might state
how the project is to be constructed and maintained, the only method of forcing compliance
with the agreement is through the courts. Alternately other methods of drain construction
under the act are con¬trolled by the municipal government, the costs are collected as taxes,
and landowners are compelled to cooperate.
Any grants outside of the Drainage Act, R.S.O. 1990 are targeted for erosion control works
rather than drainage works. A private drainage work may be eligible for grants on the
portion of the work deemed to be for erosion control rather than for the full grant on the
total cost of the works.
Mutual agreement forms are available from
Municipal World,
Box 399,
St. Thomas, Ontario
N5P 3V3.
The Tile Drainage Act, R.S.O. 1990 –
Provides loans to agricultural property owners to assist them in financing tile drainage
projects.
The Agricultural Tile Drainage Installation Act, R.S.O. 1990 –
Regulates the installation of tile drainage, e.g. contractor, business, machine licensing and
quality of work.
Common Law
Common Law forms the basis of the legal system. It always applies, unless it is specifically
altered by a statute passed by the provincial or federal governments. Common Law disputes
are arguments between landowners, and if they can’t be mutually resolved, final solutions
can be determined through the courts. More information is found in the OMAFRA Factsheet,
Top 10 Common Law Drainage Problems Between Rural Neighbours, Order No. 98-015.

Statute Laws
Statute laws are established by the legislature or parliament
in order to protect and meet the needs of the people. The
Drainage Act, R.S.O. 1990, Tile Drainage Act, R.S.O. 1990,
Water Resources Act, R.S.O. 1990, and Highway Traffic Act,
R.S. O. 1990, are examples of statutes


Common Law – The Right to Drain Land

In Ontario, we have two types of laws. “Statute law” is government legislation that is passed to provide
direction on a specific subject matter. Examples of this include the Ontario Water Resources Act, the Drainage
Act, the Municipal Act and many others. “Common law” is a system of law that is completely based on
previous court decisions and the precedence set by these decisions. This is the type of law by which civil
lawsuits are launched.

Common law always applies until it is specifically altered by statute law. To find out how common law applies,
you need to research previous court decisions. To resolve a common law problem or dispute, the complainant
has to take the offending party to court. Neither provincial ministries nor municipal governments have a role
in common law disputes unless they are part of the dispute.

On the specific subject of drainage, the courts have established two principles: (1) water in a natural
watercourse and (2) surface water. The dividing line between these two principles is the definition of a natural
watercourse, which has been defined by the courts as “a stream of water flowing along a defined channel, with
defined bed and banks, for a sufficient time to give it substantial existence…”

(1) Water in a Natural Watercourse

Water in a natural watercourse has the right to flow downstream. If a property owner blocks or dams a natural
watercourse, then he or she can be held liable for the damages caused by upstream flooding or downstream
deprivation of water. If an owner interferes with the channel of a natural watercourse and this causes damages
to another owner, the party causing the problem can be held liable.

The damaged landowner would launch a civil action to recover the damage cost from the interfering
landowner. The court decides if there is fault, damage, and makes a decision accordingly. However, a beaver
dam is considered to be a natural obstruction and an owner has no obligation to remove it for the benefit of
another owner. In fact, an owner can be held liable for damage from removing a beaver dam if the removal
floods someone downstream or deprives an upstream owner of privileges. A constructed ditch is not
considered to be a natural watercourse.

(2) Surface Water

Under the common law, surface water has no right of drainage. The courts have said that, even if water is
naturally flowing downhill to the next property, the lower property doesn't have to accept that water. They
can protect their property by building berms or dykes to stop the water coming onto their property.
The courts have also said that if a higher-elevation landowner collects or concentrates surface water (e.g., by
ditches, tiles, eavestroughs/downspouts, basement drainage, etc), and then deposits this collected water on a
lower landowner, they can be held liable for the damages.

However, if a property owner has been collecting and concentrating water onto the property of a lower
elevation property owner for over 20 years with the full knowledge of the lower owner, the higher landowner
could try to claim an easement for drain through prescriptive rights.
www.mnr.gov.on.ca/MNR/water/links.html

Contact the local Conservation Authority for more information or Conservation Ontario at
www.conservation-ontario.on.ca


Conservation Authorities Act and Section 28 Regulations
The Conservation Authorities Act was created in 1946 in response to erosion and drought
concerns, recognizing that these and other natural resource initiatives are best managed
on a watershed basis. This Act, administered by the MNR, provides for two or more
municipalities within a common watershed to enter into partnership with the Province
to establish a conservation authority (CA) for local resource management work. Today
there are 36 CAs in Ontario. Under the Act, the objects of an authority are to establish and
undertake, in the area over which it has jurisdiction, a program designed to further the
conservation, restoration, development and management of natural resources other than
gas, oil, coal and minerals.
In 2006, the Minister of Natural Resources approved the “Development, Interference and
Alteration” Regulations for all CAs (Ontario Regulations 42/06 and 146/06 to 182/06)
consistent with Ontario Regulation 97/04 made under Section 28 of the Conservation
Authorities Act. Through these regulations, CAs are empowered to regulate development
and activities in or adjacent to river or stream valleys, Great Lakes and large inland
lakes shorelines, watercourses, hazardous lands and wetlands. This “second generation”
of regulations replace the previous “Fill, Construction and Alteration to Waterways
Regulations” administered by all CAs, in some cases since the mid-1950s. They ensure
conformity of wording across all CAs and compliment municipal implementation of
provincial policies under the Planning Act such as hazardous lands and wetlands.
Development taking place on these lands may require permission from the CA to confirm
that the control of flooding, erosion, dynamic beaches, pollution or the conservation of land
are not affected. They also regulate the straightening, changing, diverting or interfering in
any way with the existing channel of a river, creek, stream, watercourse or for changing or
interfering in any way with a wetland.
Development taking place in designated “other areas” may also require permission from
the CA. Designated areas include the area adjacent to a wetland in which development
may result in a hydrologic impact to the wetland, and may include 30m or 120m from
the wetland boundary depending on the individual Conservation Authorities policy.
Development is prohibited in designated ‘other areas’ unless in the opinion of the
Conservation Authority the hydrologic functions of the adjacent wetland will not be affected
by the proposed development.
It is recommended that prior to any drainage activity being undertaken, the landowner
contact the local CA office of the proposed project site for specific application requirements
for permissions. For more information on CAs, including maps identifying where CAs are
located see Conservation Ontario’s website at: http://www.conservationontario.ca.
Class Authorization System for Southern Ontario
Fisheries and Oceans Canada and Conservation Authorities, with input from MNR have
developed a Class Authorization System to help streamline the process of reviewing fisheries
concerns for municipal drain maintenance.
Since there are many municipal drains being maintained across Ontario, this could be a
very time consuming process and cause delays for landowners needing improved drainage,
as well as for drainage superintendents trying to coordinate their work schedules. The
Class Authorization System cuts through much of that red tape. It allows municipalities,
through their drainage superintendents, to complete work such as bottom clean outs, on less
sensitive drains. Drainage superintendents can save time on planning since they will know


in advance what kind of work and timing is required for certain maintenance projects. The
Class Authorization System also helps municipalities and drainage superintendents identify
projects that might need a more in-depth examination.
For habitat management purposes, the Class Authorization System classifies municipal
drains according to their flow characteristics, water temperatures, fish species present and
time since the last full clean out.
Drainage superintendents, conservation authorities and other agencies are classifying all
municipal drains in Ontario with the goal of putting this information onto maps to help
municipalities and their drainage superintendents identify the correct steps in maintaining
a particular drain. As characteristics of the drains change, the new information is used to
update the classification.
Contact the local drainage superintendent or conservation authority for more details.
Fisheries and Oceans Canada has a set of factsheets for more information, available on-line
at www.dfo-mpo.gc.ca/oceans-habitat
The Environmental Assessment Act
The purpose of the Environmental Assessment Act, R.S.O. 1990, as stated in the Act,
is the bet¬terment of the people of the whole or any part of Ontario by providing for
the protection, conservation and wise management in Ontario of the environment. It is
administered by the Ministry of the Environment.
An environmental assessment, if required to be submitted for a project, would include:
the purpose of the undertaking, rationale for the undertaking consider¬ing alternatives,
description of environmental effects, and an evaluation of the advantages and
disadvantages. The cost of the environmental assessment is paid by the proponents
(requested for private projects).
Contact the Ontario Ministry of the Environment at www.ene.gov.on.ca for further
information.
Environmental Protection Act
The main source of environmental regulation in Ontario is the Environmental Protection
Act, R.S.O. 1990. It provides for the control of air, water and land pollution and its basic
structure is to prohibit the emission or discharge of a broad range of contaminants that
cause or are likely to cause an “adverse effect” to the natural environment. Prohibited
adverse effects include harm or material discomfort to persons; the impairment of the safety
of persons; injury or damage to property or to plant or animal life; loss of enjoyment of
normal use of property; and interference with the normal conduct of business.
The Lakes and Rivers Improvement Act
The Lakes and Rivers Improvement Act, R.S.O. 1990, gives the Ministry of Natural
Resources the mandate to manage water-related activities, particularly in the areas outside
the jurisdiction of conservation authorities. The purpose of the Act is to manage the use
of the waters of the lakes and rivers of Ontario, to regulate improvements in them, and to
provide for:
� preserving public rights in or over water
� protecting the interests of riparian owners
� management of fish, wildlife and other natural resources dependent on such waters


� preserving natural amenities
� rotecting
p persons and property by ensuring the suitability of the location and nature of
improvements while having regard to the above.
The Lakes and Rivers Improvement Act, R.S.O. 1990, applies to both private and public
lands covered by water and therefore may be applied to any drain that uses a natural stream
as a part or whole of its length and is applicable to any drains that outlet into a natural
stream or lake. A work permit is required for any activities that increases the flow, holds
back or diverts water.
Further information on this Act, the MNR Factsheet Working Around Water? – What you
should know about the Lakes and Rivers Improvement Act, R.S.O. 1990, can be seen
online at www.mnr.gov.on.ca/MNR/csb/news/crown4.html
Further information can be obtained by contacting the local MNR office or visit
The Municipal Act
The Municipal Act, R.S.O. 2001, provides the authority to the local council to pass various
by-laws that may affect the actions of the landowners with respect to drainage. Some of the
key areas of interest related to drainage include:
� uthorization
a for council to pass by-laws to enter into agreements concerning joint works
and undertakings
� power to pass by-law providing for joint management of water and sewage systems
� power to pass by-law for constructing or stopping up drains and watercourses
� passing of by-laws for prohibiting the obstruction of drains or watercourses
� by-law for filling up, draining of any grounds, and repairing private drains
� by-laws on drainage or sewage regulations
� drain connections
� by-laws on regulating construction of trenches
� by-laws for extension of sewers into adjoining municipality
� by-laws on regulating discharges into drains or sewers
� by-laws for prohibiting obstruction of ditches or culverts on highways.
Nutrient Management Act
Enacted in June 2002, the Nutrient Management Act, 2002 as amended, is intended to
control nutrients on phased-in farms so they don’t enter surface water or infiltrate ground
water. It’s also designed to control pollution from biosolids (i.e. sludge from sewage
treatment plants) when they are spread on land. The Act is administered by both the
Ministry of the Environment and the Ministry of Agriculture, Food and Rural Affairs.
A general regulation (O.Reg. 267/03, as amended) has been passed under the Nutrient
Management Act, 2002 to set out requirements regarding the application (and phasing-in)
of the Act; the development and approval of nutrient management strategies and plans; and
standards respecting land application, facility siting and construction, and sampling and
analysis.


Ontario Water Resources Act
The purpose of the Ontario Water Resources Act, R.S.O. 1990, is to preserve the
supply and purity of the natural waters. The Act is administered by the Ministry of the
Environment. There could be situations where the following sections of the Act would apply
to a project.
Every municipality or person that discharges or deposits material of any kind into any water
body or watercourse that impairs the quality of that water is guilty of an offence. When a
municipality or person pollutes a water body through discharging material into it that is not
in the normal course of events, the municipality or person must notify the minister.
Public Transportation and Highway Improvement Act
Construction on or adjacent to a provincial highway may require a permit from the
Ministry of Transportation (MTO). MTO issues permits under the Public Transportation
and Highway Improvement Act, R.S.O. 1990, and administration of the permits is the
responsibility of the Corridor Management Office. The Corridor Management Office reviews
applications from developers, municipalities, utility companies and the general public for
adherence to policies and impacts on the highway system, resolving conflicts, issuing
permits and enforcement of violation of policies.
For the purpose of this guideline, typical highway improvements may include – but aren’t
limited to – drainage works, landscaping, culverts for walkways, storm sewers, stream
diversions, watermains, sanitary sewers, underground cable or hydro lines, gas lines,
telephone cables, television cable and field surveys.
Visit www.mto.gov.on.ca/english/engineering/management/corridor/encroach.htm
for more information.
MTO has developed a number of documents and tools to address drainage and hydrology
considerations in highway design and corridor management. These tools are intended to
assist consultants, design engineers, drainage professionals and MTO staff to identify MTO
drainage policy, MTO design procedures and MTO requirements.
Visit www.mto.gov.on.ca/english/engineering/drainage/ for more information.
Permit Requirements
Permits may be required under many of the statutes. The following lists the agencies
responsible for issuing permits under the various statutes.
Ministry of the Environment
Permits may be required for the use of some herbicides on drains. Obtain permits from the
MOE, regional office or the pesticides control section, 135 St. Clair Avenue West, Toronto,
Ontario M4V 1P5, telephone 416-325-4000 or 1-800-565-4923.
If the work includes a diversion channel or dam, a permit to take water may be required
from the Ministry of the Environment. A permit to take water is required when 50,000 litres
of water is taken into storage or diverted in a 24-hour period.
A permit or certificate of approval is required from MOE whenever a contaminant is
discharged from wastewater outfall. Where the discharge is into a body of water, an
approval is required under the Ontario Water Resources Act, R.S.O. 1990, which regulates
both the taking of water for human or industrial use, and the discharge of wastes and storm
water directly into a river or lake. Before a permit or certificate of approval will be issued,


government agencies generally require detailed plans describing the nature of the discharge
source and the manner in which the level or concentration of contaminants in the discharge
will be minimized.
The Clean Water Act, S.O. 2006, will ensure communities are able to identify potential
risks to their supply of drinking water and take action to reduce or eliminate these risks.
Municipalities, conservation authorities, landowners, farmers, industry, community groups
and the public all work together to meet common goals. The effect of this legislation on soil
erosion and drainage is still not determined.
Contact the Ontario Ministry of the Environment at www.ene.gov.on.ca for further
information.
Conservation Authority
Through each CA’s individual “Development, Interference and Alteration” Regulation
Ontario Regulations 42/06 and 146/06 to 182/06) consistent with Ontario Regulation
97/04 made under Section 28 of the Conservation Authorities Act, CAs are empowered to
regulate development and activities in or adjacent to river or stream valleys, Great Lakes
and large inland lakes shorelines, watercourses, hazardous lands and wetlands.
Development taking place on these lands may require permission from the CA to confirm
that the control of flooding, erosion, dynamic beaches, pollution or the conservation of land
are not affected. They also regulate the straightening, changing, diverting or interfering
in any way with the existing channel of a river, creek, stream, and watercourse or for
changing or interfering in any way with a wetland.
It is recommended that prior to any drainage activity being undertaken, the landowner
contact the local CA office of the proposed project site for specific application requirements
for permissions. For more information on CAs, including maps identifying where CAs are
located see Conservation Ontario’s website at: http://www.conservationontario.ca.
Ministry of Natural Resources
The Ministry of Natural Resources works with many partners to develop and implement
sustainable water management programs through legislation. A permit from the Ministry of
Natural Resources may be required under the following acts:
� Lakes and Rivers Improvement Act, R.S.O. 1990
� Public Lands Act, R.S.O. 1990
� Fisheries Act, R.S.C. 1970
� for work on:
bridges (new or repair)
crown land
private land where the drainage area is greater than 5 km2
culverts
stream, rivers, creeks or lakes
open municipal drains
p
rivate land where the length of work to be done is less than 20 m and drainage
area is greater than 5 km2, or the length is greater than 20 m


municipal land where the length is greater than 20 m
Other
� for work on:
dams, channelizations, diversions, in-stream ponds and by-pass ponds on all
lands
cables or pipelines into lakes or river beds (where excavation required), for
commercial or industrial activity on all lands
Approvals are not required for agricultural drains constructed under the Drainage Act and
trenching to install heat loops, water intakes and service cables for private residences.
Public Lands Act
A work permit is a document issued by the Ministry of Natural Resources under authority of
Section 14 of the Public Lands Act, R.S.O. 1990, to authorize specific activities and works
on public lands and shore lands. A work permit is required to:
� ill
f shore lands such as creating a beach and constructing shoreline protection works (e.g.
break wall, groyne, seawall)
� dredge shore lands such as:
creating a boat slip, boating channel or swimming area
installing a water line, heat loop or cable for commercial use (i.e. marina, resort or
large scale development)
removal of rocks/boulders from shore lands or the bottom of a lake or stream
� onstruct
c a dock or boathouse where the total surface area of the supporting structure
(e.g. pipes, cribs) placed on the bed of the water body exceeds 15 m2 (161.5 ft2)
� onstruct
c a water crossing (e.g. bridge, culvert and causeway) on public land, except
where constructed under the authority of the Crown Forest Sustainability Act, 1994
� remove aquatic vegetation
Some types of activities do not require a work permit including:
� cantilever docks where the footings are located off the shore lands
� floating docks and floating boathouses
� ocks
d or boathouses where the total surface area of the supporting structure (e.g. pipes,
cribs) placed on the bed of the water body is less than 15 m2 (161.5 ft2)
� removal of an old dock or boathouse
� ice fishing huts
� installation of a water line, submarine cable or heat loop for private use
� work carried out on federal lands
For detailed information on the Ministry’s requirements for work permits, refer to Policy PL
3.03.04 – Public Lands Act, R.S.O. 1990, Section 14, Work Permits.
Fisheries Act


In areas where conservation authorities don’t exist, contact the local MNR office for
authorization requirements. Visit www.mnr.gov.on.ca/MNR/water/links.html for more
information.
Ministry of Transportation
All development and highway improvements are controlled by MTO permits under
authority of the Public Transportation and Highway Improvement Act, R.S.O. 1990,
(PTHIA). Where appropriate, a legal agreement, executed by the Minister or a delegated
authority, may be required in addition to the permit. Anyone planning to construct on or
adjacent to a provincial highway may require a permit from the Ministry of Transportation
(MTO). MTO issues permits under the Public Transportation and Highway Improvement
Act, R.S.O. 1990, and administration of the permits is the responsibility of the Corridor
Management Office. The Corridor Management Office reviews applications from developers,
municipalities, utility companies and the general public for adherence to policies and impacts
on the highway system, resolving conflicts, issuing permits and enforcement of violation
of policies. For the purpose of this guideline, typical highway improvements may include –
but are not limited to – drainage works, landscaping, culverts for walkways, storm sewers,
stream diversions, water mains, sanitary sewers, underground cable or hydro lines, gas
lines, telephone cables, television cable and field surveys.
For drainage improvements works that encroach on MTO regulated lands, a permit will
likely be required. Visit www.mto.gov.on.ca for more information.
Utilities
If a telephone line, gas or oil pipeline, or other utility is to be crossed, it’s essential they be
contacted early in the procedure so decisions can be made relative to design of the drain
on relocation of the facilities. If relocation is necessary, the time involved could be as much
as a year where new easements have to be obtained. Approval from the company may be
required prior to commencing.
“Always call before you dig.” Regardless of location and what regulations may apply,
always call One-Call or individual companies to ensure work will not interfere with buried
facilities.

B E S T M A N A G E M E N T P R A C T I C E S � G L O S S A R Y 2 0 3

APPENDIX 2
Glossary

B E S T M A N A G E M E N T P R A C T I C E S � C R O P L A N D D R A I N A G E 2 0 5

Agricultural Drainage

More Related Content

What's hot

Viewers also liked

Similar to Agricultural Drainage

Recently uploaded

Agricultural Drainage