RAIN WATER HARVESTING STATE LEVEL NODAL AGENCY TAMIL NADU WATERSHED DEVELOPMENT AGENCY

RAIN WATER HARVESTING STATE LEVEL NODAL AGENCY TAMIL NADU WATERSHED DEVELOPMENT AGENCY

Reasons for Shortage of Water Increasing Population Industrialization Urbanization Degradation and pollution of lands Increasing in area under well irrigation resulting in increased ground water exploitation Reduction of capacity in surface storages like ponds, lakes, tanks etc. Deforestation Lesser & Inconsistent Monsoon

How To Overcome The Crisis? Conserving runoff from minor catchments through in situ practices Treating the Catchment area by suitable soil conservation measures Curtailing the surplus flow during the rain allowing minimum flow as drain Standardization of existing water harvesting structures like ponds, tanks and lakes constructing new recharge structures at feasible locations or places Harvesting and Storing maximum quantity of rainwater during monsoon period for direct use or to recharge the ground water aquifer Bridging the gap between availability and demand by efficient watershed management

Artificial Recharge Structure: Recharge Shaft

Utilization of Defunct Bore well There are many bore wells sunk in streams or gullies, ponds and tanks for drinking water purpose in the watershed areas. Out of this many are defunct or unused or out of use. These defunct bore wells are taken for recharging the aquifer directly Defunct bore well

Construction Creation of dugout pit around the bore well The casing pipe in the bore point has been replaced by perforated or slotted pipe of length 1.50m with end cap. The perforated pipe is covered with nylon/wired mesh for arresting the silt entering into the bore well.

Construction Around the pipe portion 5 numbers of precast RCC rings of size 1.00m diameter with 0.30m height is placed one and above, In that ring portion the bottom layer is filled with 40mm HBG jelly to a depth of 0.60m Then 20mm HBG jelly is filled to a height of 0..60m as middle layer. So the ring portion is initially filled with bigger size jelly followed by smaller one. A nylon/wired mesh is placed above the layer of 20mm jelly to arrest the silt entering into the filter medium.

Construction Finally fine river sand is filled as a top layer for the remaining portion of the ring i.e.. 0.30m. The top of ring portion covered with precast RCC round slab. The filter medium of recharge structure is protected with locally available boulders if necessary.

Functioning Of Recharge Shaft

Advantages of This Structure Augments the ground water resources. Stores the surplus surface water particularly the flood periods for future use and reduce the flood peaks. Retards the surface runoff and to penetrate the overlying impervious strata. Recharges the aquifers. Improves the water quality of ground water in fluoride affected areas.

Cost for Recharge Shaft in Defunct Bore well

EXPANSION OF RECHARGE SHAFT WORKS This type of work is being implemented in all districts of Tamilnadu through NMSA scheme in a total outlay of `695.40 lakhs for 1159 nos under the component of Rain fed Area Development (RAD) value addition and resource conservation during 2014-15.

Various Type Of Filter Medium

NLM VISIT WC VISIT

Recent Press News TIRUCHIRAPPALLI DISTRICT TODAY'S PAPER» NATIONAL» TAMIL NADU TIRUCHI, November 15, 2014 Village ponds bubble with life thanks to IWMP District Watershed Development Agency officials inspecting a village pond at K.Periyapatti in Manapparai block in Tiruchi district on Friday. PHOTO: R. M. RAJARATHINAM Village ponds in Tiruchi district being improved under the Integrated Watershed Management Programme (IWMP) have started showing appreciable increase in storage. One such small and shallow pond at K.Periyapatti village in Manapparai block now shows perceptible increase in storage thanks to the programme implemented by the District Watershed Development Agency (DWDA). The pond now stores more water and the water table around the pond also shows increase. Ilanjiyam, a woman of the village, said that now they have adequate water for both drinking and bathing. V.Selvaraj, president of the village, said that water level in the borewells surrounding the area has also improved. P.Prasad, Assistant Executive Engineer, DWDA, said that dredging work was carried out in the pond silted up and covered with bushes. The bed level of the pond was maintained and excavated soil in the water spread area was deposited on the bunds uniformly, consolidated and sectioned. Yet another unique feature of the pond was the creation of recharge shaft. It was the most effective structure to recharge the aquifer directly. A new borewell was erected in the pond. A filter medium was created around the new borewell. Arrangements have been made to impound the rain water to the shaft. The impounded water enters the bore through the filter medium which recharges the aquifer directly. The structure augments the groundwater resources, stores surplus water, particularly during floods, for future use, and reduces floods and surface runoff, Mr.Prasad said. The pond renovated at a cost of Rs. 2.50 lakh can now hold 0.6 million cubic ft of water. At Sevalur in the same block, another village pond has been improved. Here a check dam has been built to regulate the flow of water. M.Selvaraj, vice-president, Manapparai panchayat union, said the pond renovated at a cost of Rs. 2.81 lakh can now hold 0.7 million cubic ft of water. Under IWMP, a new farm pond has been created at Pirampatti in Marungapuri block at a cost of Rs. 50,000. R.M.Lakshmanan, Deputy Director of Agriculture, and N.Kannan, Assistant Director of Agriculture, DWDA, said that in Tiruchi district, 202 ponds have been renovated at a cost of Rs.1.35 crore. In the last three years, 118 farm ponds have been created at a cost of Rs. 52.50 lakh. A percolation pond has also been constructed at Nattarpatti village in Marungapuri block at a cost of Rs.2.82 lakh. A percolation pond is a small harvesting structure constructed across a natural stream or water course to harvest and impound runoff from catchments for a long time, to facilitate vertical and lateral percolation of impounded water in to the soil sub-strata, thereby recharging groundwater in the zone of influence of the pond. In Tiruchi district, in the last three years, 42 percolation ponds have been constructed at a cost of Rs. 60 lakh. S.Mathiyalagan, Joint Director of Agriculture and Project Officer, IWMP, and Pandiyarajan, PA to District Collector, said that IWMP is implemented with Central and State government funds. In Tiruchi district, the scheme was being implemented in Pullampadi, Thuraiyur, Marungapuri, Thottiyam, Vaiyampatti, Musiri, Thathaiyangarpettai, Manapparai and Uppiliyapuram blocks covering 14 IWMP scheme since 2009. About 78,749 hectares of land have been taken for treatment under the scheme, with a project outlay of Rs.94.50 crore. Till date, Rs.14.11 crore had been received of which Rs.615 lakh had been spent.

Ramanathapuram Chairman/District Collector inspecting the Desilting Channel (IWMP) in Muthugalathur block.

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