Importance of farm pond for agriculture and farmers in Manipur

Dr L Kanta Singh, Dr Ch Basudha, Dr Lydia Zimik, Dr Arati N, Dr S Roma Devi, K Lily Rangnamei and Dr W Elizabeth Devi
Contd from previous issue
These types of farm pond are used for irrigation and fish farming purposes. Farm ponds of the dug-out variety are constructed using rainfall, land slope, catchment area, run-off, and seepage characteristics. Seepage is taken into consideration when designing the pond. Construction of a farm pond is impractical in places with sandy soil content since seepage loss is significantly greater there.
Farm ponds of the dug-out variety are built by removing soil from the ground, primarily in flat locations.
The intended water storage capacity of the pond, which is nearly entirely attained via excavation, is used to determine the depth of the pond.
This kind of pond can be used, especially when only a modest amount of water is needed.
In addition to the aforementioned two types, there are two more types of farm ponds, namely spring fed and off-stream storage pond, depending on the sources of water that can be used to feed them. Data on rainfall, runoff, evaporation, and seepage are fundamentally needed to construct a dugout pond.
One of the key considerations in pond design is “seepage.” For instance, in places with high sandy levels, seepage loss is substantially higher, making the construction of farm ponds impracticable. Although, everywhere there is seepage owing to ponding of water but it should be under favourable limit.
When estimating the minimum storage, it is typically advised to allow seepage loss at a rate of 1 m of water depth each year. The depth of farm pond also fluctuates as per climatic condition.
Typical average pond depth based on climatic condition
Sl. No. Climate Average depth (m)
1. Wet 2.00
2. Humid 2.40-2.80
3. Moist sub-humid 2.80-3.15
4. Dry sub-humid 3.15-4.00
5. Semi-arid 4.00-4.80
6. Arid 4.80-5.50
A general method to design a dugout farm pond is presented under the following steps:
1. Get the essential information about the location.
(a) Rainfall, evaporation, temperature etc.
(b) Topography
(c) Agricultural practices
(d) Livestock etc.
. Determine the pond’s needed storage capacity. On the basis of agricultural practices and number of livestock, it is decided. The amount of water anticipated to lose by evaporation and seepage, plus about 10% more to adjust certain unforeseen water losses from the pond, is also added to establish pond storage capacity.
Assess the farm pond’s catchment area to provide the necessary storage. The area’s topographic map is used to carry out the task.
Select a desirable pond depth.
Make field investigations of the sites, selected. Normally, the following considerations are made to assess the most desirable one.
(i) Should be easily accessible.
(ii)  It should require less removal of trees.
(iii) The site should have suitable foundation conditions for the dam.
(iv) It should not have excessive seepage through the foundation.
(v) The site should have suitable materials for dam construction in nearby areas.
(vi) There should be a natural waterway to use as emergency spillway.
Based on above necessary conditions, the site which proved preferable in all respects is picked for pond construction.
6. To ensure the required storage capacity and depth of water, determine the pond and dam dimensions for the chosen site.
7. Calculate the farm pond’s maximum depth, taking extra depth into account for sedimentation and excessive seepage.
8. Fix the emergency spillway’s crest, which is typically fixed at the pond’s highest level.
Farm ponds can be cost-effective structures that can transform livelihoods of many farmers of Manipur.
They can help enhance water control, contribute to agriculture intensification and boost farm incomes.
However, this is possible only if they act as rainwater harvesting structures. The small holding farmers in the Manipur currently use a family farming method, but there are always water scarcity problem occurred at various levels.
The adoption of scientific farm pond for management of various components will not only increase the effectiveness of resource use in the current production system but will also help move small-holder family farming production systems one step closer to sustainability in the future by minimising its negative effects on the environment through proper water recycling.