Sub Surface Dykes

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5.Sub Surface Dykes

Sustainability of Sources - Success Stories Sustainability through Sub Surface Dykes, Venganoor Village, Perambalur District, Tamilnadu.

Under PMGY 2003-04 Programme, a Sub surface dyke was constructed near Venganur habitation of Venganur Panchayat in Veppanthattai union of Perambalur District.

The Veppanthattai block comes under over exploited category wherein the present stage of ground water development exceeds 100%.

The location of the recharge structure is in close proximity to the drinking water head works. The people of the Venganur habitation have been sensitized about the necessity for construction of Subsurface Dyke and its benefit consequent on implementation.

The Recharge structure - Sub surface dyke is the barrier constructed across the river below the riverbed, which facilitates the arrest of subsurface flow. The efficacy of recharge because of this sub surface dyke would be is more positive in the upstream side.

The subsurface dyke is constructed across an odai near Venganur (which confluences with River Manimuthar) for a length of 65m with the top width of 200m. The depth of the structure is 3m of which the depth below the bed level is 0.15m.The cost of the sub surface dyke is Rs.7.55 lakhs. The work of construction of check dam commenced during June 2003, and completed in December 2003.

To access the impact of the check dam, water level monitoring has been done month wise, sinceJanuary 2004, and it is observed that a rise in water level from 12.0 m in Jan 2004 to 5.90 in May 2008.

The level of supply in the nearby habitation Periyammapalayam was 25 lpcd, has been enhanced to 48 lpcd based on the recent survey.

Apart from benefiting the existing sources of drinking water supply improvement in water level is observed in nearby agricultural wells also.