Subsurface dykes
Subsurface dykes are
built in an aquifer to obstruct the natural flow of GW, thus raising the GW
level and increasing the quantity of water stored in the aquifer. These are
performing as an underground obstruction impermeable to water. These controls
GW flow in an aquifer and increases the GW table. These essentially comprise of
brick masonry structures constructed on massive crystalline rocks, which are
exposed in trenches of 1-2 m wide, dug across the breadth of the stream down to
impervious bed. The space between the structure and the walls of the trench may
be filled by impermeable clay. These are found to be cost-effective
alternatives for providing sustainable drinking /irrigation water supplies to
small communities in areas where construction of other artificial recharge
structures cannot be attempted due to adverse geomorphologic conditions or
constraints of space.