KANNUR: A sub-surface dyke at Panniyur, here, is serving as a model for effective groundwater conservation.
The dyke, constructed at the Krishi Vigyan Kendra (KVK), under Kerala Agricultural University (KAU), with the support of the Indian Council of Agricultural Research (ICAR), is part of a demonstration of rain-water harvesting technologies.
The sub-surface dyke, said to be the largest rain-water harvesting system in the region, was constructed on a 25-hectare farm of the KVK at the Pepper Research Station at Panniyur in 2007 to solve water scarcity. The dyke has proved to be an effective barrier against the sub-surface flow of water and has helped conserve groundwater. It has checked the high rate of water depletion in the catchment area. It has also helped in maintaining a higher water table in the catchment area for an extended period. The sub-surface dyke is a structure built in an aquifer to obstruct the natural flow of groundwater, thereby raising its level and increasing the amount of water stored in the aquifer, KVK head K. Abdul Kareem says. The dyke is a demonstration of one of the most feasible methods of conservation and exploitation of groundwater resources in the State, he says.. He says a pond in the upstream of the dyke that usually dried up in summer now has water throughout the year with the dyke ensuring supply of water to it.
The sub-surface dyke is an answer to the problem of high water run-off owing to the undulating topography. Dr. Kareem says a wide and sloping valley with a narrow outlet having loose soil or porous rocks of limited thickness on top and massive rocks below is the ideal location for building the dyke. There is no loss of agricultural land and the cost of maintenance is negligible.