The document discusses various water conservation measures, focusing on farm ponds and related structures for water harvesting. It details the design, construction, and types of farm ponds, emphasizing factors for site selection and the types of ponds available based on water sources. Additionally, it covers macrocatchment and microcatchment water harvesting systems for effective water management in agricultural contexts.

1. SOIL AND WATER
CONSERVATION ENGINEERING
S.Satheeshkumar
AP/AGE
Kongunadu College of Engineering and
Technology
Trichy

2. UNIT IV WATER CONSERVATION MEASURES
In-situ soil moisture conservation – Water harvesting principles and
techniques: Micro catchments, catchment yield using morphometric
analysis – Farm ponds: Components, Design, Construction and
Protection – Check dams – Earthen dam – Retaining wall.

12. Farm ponds are small tank or reservoir-like constructions,
built for the purpose of storing the surface runoff,
generated from the catchment area. Farm ponds are
water harvesting structures that meet many farm needs.
 Supply of water for irrigation
 Cattle feed
 Fish farming, etc.
FARM PONDS

13. A pond that is about 10 meters by 10 meters
and 3 meters deep is an ideal size. The pond
should have an inlet and an outlet (as shown
in the picture) lined with rock to prevent
erosion.

14. The design of farm ponds includes
determination of capacity, its location,
utilization plan and shape and size. Where
CWR is the crop water requirement, DR is
the design rainfall, RC is the runoff
coefficient, RE is runoff efficiency factor,
Aca is the catchment area and Acu is the
cultivable area.
THE DESIGN OF FARM PONDS

15. DESIGN OF FARM POND
• S election of site
• Determination of the capacity of the pond
• Design of the embankment
• Design of the mechanical spillway
• Design of the emergency spillway
• Providing for seepage control from the bottom

16. Excavated ponds are built in flat areas by digging
out an area as big as needed for the pond
The banks (bund) of an embankment pond are
built above ground level.

17. TYPES OF POND
Depending on the source of water and their location with respect to
the land surface, farm ponds are grouped into four types.
These are
• Dug out ponds
• Surface ponds
• Spring or Creek fed ponds and
• Off stream storage ponds

18. DUG OUT PONDS
Dugout ponds are constructed by
excavating the soil from the ground
and the excavated soil is used to
make embankment around the pond.
The pond could either be fed by
surface runoff or groundwater
wherever aquifers are available. The
depth and size of pond depend upon
the volume of water to be stored.

19. SURFACE PONDS
• Surface water ponds are
the most common type of
farm ponds.
• These are partly excavated
and an embankment is
constructed to retain the
water

20. SPRING OR CREEK FED PONDS
• Spring or creek fed
ponds are those where a
spring or a creek is the
source of water supply to
the pond.
• Construction of these
ponds, therefore, depend
upon the availability of
natural springs or creeks.

21. OFF STREAM STORAGE PONDS
• Off stream storage ponds are
constructed by the side of streams
which flow only seasonally.
• The idea is to store the water
obtained from the seasonal flow in
the streams.
• Suitable arrangements need to be
made for conveying the water from
the stream to the storage ponds.

22. factors to consider in farm pond site selection
 Land topography. -shape, height, and depth
 Vegetation cover.
 Water supply – quantity and quality.
 Soil type. – physical and chemical properties
 Proximity to farm produce market. –Nearness or Closeness
 Proximity to good road network.
 Power supply.
 Largest volume of water can obtained with less earthwork

23. PERCOLATION PONDS
A percolation pond is
a small water
harvesting structure,
constructed across a
natural stream or
water course to
harvest and impound
the runoff from the
catchments for a
longer time, used for
recharging
Water infiltrates the soil by moving through the
surface. Percolation is the movement of water

24. CHECK DAM
A check dams is a small, sometimes
temporary, dam constructed across a
hollow place, drainage ditch, or waterway
to counteract erosion.
 Reduce flow velocity.
 Allowing sediment to settle out.

25. EARTHEN DAMS
An embankment dam is a large artificial
dam. It is typically created by the
placement and compaction of a complex
semi-plastic mound of various
compositions of soil or rock.

26. RETAINING WALLS
Retaining walls are often found in places
where extra support is needed .to
prevent the earth from moving downhill
with erosion
A wall that is built to keep the land
behind it from sliding.
Retaining walls are relatively rigid walls
used for supporting the soil

27. Macrocatchment water harvesting
 Macrocatchment water harvesting (MacroWH) systems usually consist of four
components:
 The catchment area
 The runoff conveyance system
 The storage system
 Application area.
In the catchment area, rainwater runoff is collected from compacted surfaces,
including hillsides, roads, rocky areas, open rangelands, cultivated and
uncultivated land and natural slopes. Most MacroWH practices have a catchment
area of less than 2 ha, in some cases however runoff is collected from
catchments as large as 200 ha. The runoff is conveyed through overland, rill,
gully or channel flow and either diverted onto cultivated fields

29. Microcatchment water harvesting
systems
 Microcatchment water harvesting
systems (MicroWH) are designed to
trap and collect runoff from a
relatively small catchment area,
usually (10 – 500 m2
) within the
farm boundary.
 The runoff water is guided into an
application area where it
accumulates in holes, pits, basins
and bunds.

30. Thank you