This presentation gives an overall idea of processes, techniques and methods of storm water management in rural and urban areas

1. STORM WATER MANAGEMENT AND ITS
TECHNIQUES
FUNDAMENTALS OF ECOLOGY
( M. ARCH. – I SEM. )
PRESENTED BY:
RAJAT NAINWAL
17M809

2. Storm water is
rainwater and melted
snow that runs off
streets, lawns and
other sites. When
storm water is
absorbed into the
ground, it is filtered
and ultimately
replenishes aquifers
or flows into streams
and rivers.
WHAT IS STORM WATER ?

3. WHY DO WE NEED TO MANAGE STORM WATER?
To avoid :-
• Downstream flooding.
• Stream bank erosion.
• Increased turbidity from erosion.
• Habitat destruction.
• Combined sewer overflows.
• Infrastructure damage.
• Contaminated streams, rivers, and coastal water.

4. • Because impervious surfaces do not allow rain to infiltrate into the
ground, more runoff is generated than in the undeveloped condition. Due
to this reduction of level of water table advances and depletion of ground
water resource occurs which is a key factor to severe drought and scarcity
conditions.
• To avoid flooding in transportation corridors and to control damage to
properties.
• Both cases can cause severe damages and contamination of the
environment if sanitation facilities are flooded. This results in high costs
and notably massive suffering for the local communities.

5. ADVANTAGES
• Provides proper drainage of surface run-off and avoids damages on infrastructure such as
private properties and streets.
• Provides possibility to recharge groundwater and re-use precipitation water and surface
run-off as irrigation or household water.
• Minimizing health risks.
• Provides effective storm water flood control.
• Can be integrated into the urban landscape and provide green and recreational areas.
• Revenue generated by a storm water utility can be used as a new, dedicated source of
funds to supplement or replace the community's current storm water management
funding, enabling tax-based funding to be used for other community needs.
• Expert planning, implementation, operation and maintenance required for a storm water
management.
• It depends on the technique, a lot of operation and labour required.
• There is risk of clogging infiltration system caused by high sedimentation rates.
• Temporary covering methods, such as plastic sheeting, can become torn or ripped,
exposing the contaminant to precipitation and/or storm water runoff.
STORM WATER MANAGEMENT
DISADVANTAGES

6. Green infrastructure functioned as water management that protects,
restores, or mimics the natural water cycle.
Gray infrastructure is man-made designed to move urban storm-water
away from the built environment.
Both infrastructure are involved in storm water management system.
GREEN INFRASTRUCTURE & GREY INFRASTRUCTURE

7. Flooded agricultural land after a storm event.
RURAL STORM WATER MANAGEMENT
CAUSES:
- Heavy rainfalls
- Storms
- Overstrained sewer systems
IMPACTS:
- Flooding and stream erosion
BENEFIT OF FLOOD EVENTS
AND PRECIPITATION:
- Use this water for irrigation.
Some available techniques:
• Spate irrigation
• Micro basins
• Field trenches

8. 1. SPATE IRRIGATION SYSTEM
RURAL STORM WATER MANAGEMENT
Spate irrigation is a crop irrigation technique
consisting of diverting seasonal storm
water from valleys, rivers, riverbeds and gullies
by gravity onto farmland situated at a lower
elevation than the flood water. The flood water is
then diverted to the fields. After the land is
inundated crops are sown, sometimes
immediately, but often the moisture is stored in
the soil profile and used later.
ADVANTAGES
• Big areas can be irrigated.
• Floods can be controlled.
• In areas traditionally irrigated by spate irrigations, groundwater source are relatively rich due
to long periods of recharge.
DISADVANTAGES
• Sediments in the irrigation water (if they were not removed properly) can cause problems on
crops and soil.
• Amount of available water varies from year to year.
• River beds may change and spate irrigation constructions need to be adjusted.
A large spate irrigation construction
Source: B. STAUFFER (2011) adapted from FAO

9. Micro basins are a common technique used in
agriculture to collect surface run-off, increase water
infiltration and prevent soil erosion. Their principle is
comparably simple: small pools are surrounded by
stone walls and/or soil ridges on all sides to collect
the rainwater and surface run-off. This allows storing
rainwater and using it for small-scale tree and bush
planting, enabling increased growth of plants if there
is a moisture deficit.
ADVANTAGES
• Simple design and construction.
• Can be applied to even and uneven grounds.
• Applicable for very small scale (e.g. only for a few trees).
DISADVANTAGES
• Only applicable to small scale, mainly because their implementation is not easily mechanized.
• Soil needs to have considerable depth (at least 1.5 m).
• Bunds have to be repaired immediately if they break.
Water accumulates in the pit on the lowest part of the micro
basin.
Source: ALI et al. (2009)
2. MICRO BASINS
RURAL STORM WATER MANAGEMENT

10. Field trenches increase precipitation harvesting by
breaking the slope of the ground and therefore
reducing the velocity of water runoff. By
decreasing runoff, they enhance water infiltration and
prevent soil erosion. Trenches can be seen as an
extended practice of ploughing fields.
ADVANTAGES
- Applicable to all soil and rainfall conditions.
- Prevents soil degradation and erosion.
- Enhances surface water infiltration and soil moisture.
- Helps to reduce flood hazards.
- Comparably simple construction, requiring only basic
construction material.
DISADVANTAGES
- Intense labour is needed for maintenance.
- Less land is available for cultivation.
- May create temporary water logging in dense soil.
Continous contour trenches.
Source: SUSSMAN (2007)
3. FIELD TRENCHES
RURAL STORM WATER MANAGEMENT

11. The practice of managing freshwater, wastewater, and storm water as links within the resource
management structure, using an urban area as the unit of management is known as Integrated Urban
Water Management (IUWM).
Human settlements disturb the natural water cycle and creates floods and water pollution.
• Natural vegetation is often removed and rivers are canalised.
• Surfaces are impermeable.
• Groundwater resources decrease, fresh water becomes scarce.
There are several techniques to manage surface runoff. They are divided in two groups:
• Storage Type Devices
• Infiltration Type Devices
What technique is implemented should be decided on local conditions and responsible planers.
Let’s upgrade the urban water cycle! Source: AUCKLAND CITY COUNCIL (2010)
URBAN STORM WATER MANAGEMENT

12. 1. DETENTION PONDS
• These are the excavated reservoirs or natural depressions.
• Dry during low flow periods i.e. temporary storage during flood events.
• Storm water should stored long enough to settle solids.
URBAN STORM WATER MANAGEMENT – STORAGE TYPE DEVICES
Extended Detention Basin Components.
Source: NJDEP (2004)

13. • Primarily designed to improve storm water quality.
• Secondary for flood control devices.
• Retention Ponds do not dry out, water stays between 2 and 4 weeks.
• Water quality improvement mainly through settling.
A retention pond with additional aeration, which improves aquatic life and pollutant removal.
Source: KASCO MARINE (N.Y.)
2. RETENTION PONDS
URBAN STORM WATER MANAGEMENT – STORAGE TYPE DEVICES

14. • Can be used in urban and rural areas.
• Reducing of storm water runoff and storage of potable water
• Water can be used for irrigation, as flush water for toilets or, after purification, as
drinking water.
Rooftop rainwater harvesting
in Urban Areas using a Plastic
Tank.
Source: VISHWANATH (N.Y.)
3. RAIN WATER HARVESTING
URBAN STORM WATER MANAGEMENT – STORAGE TYPE DEVICES

15. 4. GREEN ROOFS ( LIVING ROOFS )
URBAN STORM WATER MANAGEMENT – STORAGE TYPE DEVICES
• Green roofs consist of a vegetative layer that grows in a specially-designed soil that may sit above
a drainage layer.
• Green roofs detain storm water in the void space of the soil media and retain storm water through
vegetative uptake and evapotranspiration.
• They provide an excellent insulation.
• Reduce energy consumption significantly.

16. INSTALLATION PROCESS OF GREEN ROOF
• Install a monolithic type waterproof membrane such as rubber and plastic on top of the roof
decking.
• Place a 6mm sheet of plastic on the waterproof membrane and the waterproof membrane will serve
as a root barrier.
• Top the first two layers with one or more thin sheets of three-quarter-inch foam insulation suited for
contact with damp soil.
• Set a drainage mat which also called as a dimple mat with capillary spaces on top of the insulation.
• Frame the sides for the roof with mesh gutter guards, wood or other edging that will permit
drainage to hold soil in place.
• Add soil.
• Set plants in place.
• Water to settle soil around plants.

17. • Designed to manage peak flows and to improve water quality of surface runoff.
• Restoring natural habitats in cities (recreation, birdlife, etc.).
5. CONSTRUCTED WETLANDS
URBAN STORM WATER MANAGEMENT – STORAGE TYPE DEVICES
A possible design is a pond/wetland system. First pond (left) reduces velocity and removes
pollutants. The shallow marsh system stores water and is an additional treatment.
Source: METROCOUNCIL (N.Y.)

18. • Shallow excavations filled with uniformly crushed stones.
• Walls and top lined with geo-textile to avoid sediment penetration.
• Runoff infiltrates through the trenches into the subsoil.
• Treatment occurs during infiltration.
• Constructed beside streets and outdoor parking lots.
1. INFILTRATION TRENCHES
URBAN STORM WATER MANAGEMENT – INFILTRATION TYPE DEVICES
Design of infiltration trenches.
Source: RIVERSIDE (N.Y.) and SUSTAINABLE STORMWATER MANAGEMENT (2007)

19. 2. VEGETATED SWALES
URBAN STORM WATER MANAGEMENT – INFILTRATION TYPE DEVICES
• Open grassed channels, which allow an infiltration along the course.
• Check dams and vegetation reduce velocity, and allow sedimentation,
infiltration, evapotranspiration and contaminant removal.
Enhanced grass swales feature check dams that temporarily pond runoff to increase pollutant retention and infiltration and decrease flow velocity.
Source: TRCA & CVC (2010)

20. INSTALLATION PROCESS OF VEGETATED SWALES
• Rough grade the
vegetated swale.
• Construct check dams, if
required.
• Fine grade the vegetated
swale.
• Prior to establishment of
vegetation, a swale is
specifically vulnerable
to scour and erosion and
therefore its seed bed
must be protected with
temporary erosion
control.
• If all tributary areas are
enough stabilized,
remove temporary
erosion and sediment
controls.

21. A theoretical cross section of porous pavement (left) and porous pavement during a demonstration.
Source: TECOECO (N.Y.)
3. POROUS PAVEMENTS
URBAN STORM WATER MANAGEMENT – INFILTRATION TYPE DEVICES
• Permeable pavement surface with a stone reservoir underneath.
• Reservoir stores runoff water temporarily.
• Afterwards, stored water is subsurface drained or infiltrates into the subsoil.
• Often appears the same as traditional asphalt or concrete but is manufactured with incorporates void
spaces that allow for infiltration.

22. • Constructed facility with highly permeable soils.
• Water infiltrates into surrounding soil and gets treated.
An infiltration basin.
Source: VUSP (N.Y.)
4. INFILTRATION BASIN
URBAN STORM WATER MANAGEMENT – INFILTRATION TYPE DEVICES

23. • Constructed depression
• Larger than rain gardens and designed with an underdrain to connect to the storm drain
system.
BIORETENTION AREAS

24. STREAM BUFFER RESTORATION
• Native trees and bushes planted along the stream or ditch.
• Strips of trees and other vegetation buffer helps improve water quality and maximized stream
damage.
• By filtering and slowing polluted runoff .
Types of Buffer Zones:
1. Stream Side Zone- This is the closest zone to the stream. The trees and other types of plants
physically protect the stream from runoff, erosion and provide shade to cool the water. A mature
wooded forest and dense shrubs are preferred to hold the soil together and provide suitable habitat for
fish.
2. Middle Zone- This is the zone that filters, slows down, and absorbs run off before it enters the
stream. Wetlands or a forest capture and store sediment, nutrients, and other pollutants. On farmland,
shrubs and grasses works just as well as forest.
3. Outer Zone- This is the ‘buffer’ of the buffer. It is the farthest zone from the stream and closest to
the roads, farmland, and towns. Trees, shrubs and grass will absorb and filters surface runoff into the
soil.

25. STREAM BUFFER RESTORATION

26. • Blue roofs, also known as controlled flow roof drain systems, provide temporary ponding
on a rooftop surface and slowly release the ponded water through roof drains.
• Blue roofs have weirs at the roof drain inlets to restrict flow.
BLUE ROOFS
Weirs with predetermined flow rates at
various ponding depths control the release
rate from a controlled flow roof drain.
Controlled Flow Roof Drain

27. GUTTERS
Gutters are channels fixed to the edges
of roof all around to collect and
transport the rainwater from the roof
to the storage tank. Gutters can be
prepared in rectangular and semi-
circular shape.
Strom drains Section showing the details of installed gutter with down pipe

28. TREATMENT OF STORM WATER
• Contaminants in water may include algae, air pollution, bird excrement, and
leaves, sand, and dust. Local wells have dealt with these problems for decades.
• Installation of filtration and purification equipment can remove these
contaminants at home as well.
• First, take measures to keep foreign matter out of the incoming rain water, flush
devices, gutter screens and other screening mechanisms keep the rainwater as
clean as possible before it enters the conveyance system.
• Using screens and filters will greatly reduce maintenance and lengthen the life of
the pump and filtration / purification system.

29. • One of the more expensive but effective purification treatments for rainwater is
that of a combination of filtration and UV treatment.
• Physical filters “remove particulates, and the UV-light chamber…kills bacteria
and other organisms by exposing them to high-energy ultraviolet light.”
• These systems are expensive to install, but also cost quite a bit annually. The UV
light stays on all year, so electricity costs are, relatively, quite high.
1. FILTRATION AND UV TREATMENT
Filtration and UV Treatment

30. • People commonly use household bleach for this process, which is of concern to some due to
the chemical factor.
• Wind up boiling the water first, then adding several drops of chlorines into a quart of rainwater.
• Allowing at least 30 minutes for the chlorine to disinfect your water if the water is 70 degrees
F or above.
• Allow up to an hour if the water is near freezing.
2. CHLORINATION

31. • This is one of the more labour – intensive purification processes, but it also winds up
being a bit more natural in leveraging the sun for purification.
• A one-quart Ziploc bag be filled with water, and that the bag be placed on two feet
of aluminum foil, shiny side up in a very sunny place.
• The bag needs to heat for several hours and the water should remain at 160F or
higher for at least that long so that waterborne pathogens can be successfully
eliminated.
3. SOLAR PASTEURIZATION

32. • www.envfor.nic.in - Ministry of Environment, Forest and Climate change.
• www.sswm.info - Sustainable Storm Water Management.
• www.fao.org - Food and Agricultural Organization.
• www.ifad.org - The International Fund for Agricultural Development.
• www.nymtc.org - New York Metropolitan Transportation Council.
• www.aucklandcouncil.govt.nz - Auckland City Council.
• www.slideshare.net
• www.google.co.in
REFERENCES