Artificial recharge and rainwater harvesting techniques can help address groundwater scarcity issues in Kerala. The document outlines various methods for artificial recharge like flooding basins, injection wells, and recharge pits. It also discusses rainwater harvesting through storage surfaces and recharging groundwater via pits, trenches, and wells. Benefits include increased groundwater levels, drought mitigation, reduced runoff and flooding, improved water quality, and energy savings. Case studies demonstrate implementing these techniques.
1. Artificial recharge and Rain
water harvesting –Case studies in
Kerala
A.Subburaj,Scientist-D
Central Ground Water Board
Kerala Region,Trivandrum
2. Major causes for scarcity
• Rainfall pattern
• Geomorphological set up
• Drainage
• Sand mining
• Hydro geological factors
• Over exploitation
• Reclamation of land for settlement
3.
4. Definition
• Augmentation of ground water reservoir by man
made structures by using rain water.
• Rain Water Harvesting is deliberate collection
and storage of rain water
5. Methods of Artificial Recharge
a.Direct surface techniques
. Flooding
. Basins or percolation tanks
. Stream augmentation
. Ditch and furrow system
. Over irrigation
b.Direct subsurface techniques
. Injection wells or Recharge wells
. Recharge pits and shafts
. Dug well recharge
. Bore hole flooding
. Natural openings,cavity filling
c.Combination of Surface-Subsurface techniques
. Basin or percolation tanks with pit shaft or wells
d. Indirect Techniques
. Induced recharge from surface water source
.Aquifer modification
6. Rain water Harvesting
a.Storage of rain water on surface for future
use
b.Recharge to ground water
- Pits
- Trenches
- Dug wells
- Hand pumps
- Recharge wells
- Recharge shafts
- Lateral shafts with bore wells
- Spreading techniques
7. Benifits
• An ideal solution to water problems in areas having
inadequate water resources
• The ground water level will rise
• Mitigates the effects of drought & achieves drought
proofings
• Reduces the runoff which chokes the storm water drains
• Flooding of roads and low land areas are reduces
• Quality of water improves
• Soil erosion will be reduced
• Saving of energy per well for lifting of ground water-a one
meter rise in water level saves about 0.40 KWH of
electricity.
8. Cost
S.No Recharge structure Approximate cost
(in Rs)
1 Recharge pit 2500-5000
2 Recharge trench 5000-10000
3 Recharge through hand
pump
1500-2500
4 Recharge through dug well 5000-8000
5 Recharge well 50000-80000
