Section 4: Soil and Water Conservation Engineering
Watershed Management
Subtopic: Rainwater harvesting
Question Statement:
Which of the following artificial groundwater recharge structures are widely adopted in hard-rock and alluvial watersheds to enhance aquifer replenishment?
Options:
(A) Percolation tanks constructed across permeable stream beds
(B) Recharge shafts and recharge pits for shallow unconfined aquifers
(C) Subsurface dykes (groundwater dams) built across riverbed sand strata to arrest baseflow escape
(D) Direct injection tube wells for deep confined aquifers
Answer Key:
A, B, C, D
Step-by-Step Solution & Explanation
All four techniques are established artificial recharge structures:
- A: Percolation tanks impound runoff over permeable formations.
- B: Pits and shafts bypass impermeable top clay layers.
- C: Subsurface dykes dam underground flow in permeable river sand beds.
- D: Injection wells convey pre-treated surface runoff into depleted deep confined aquifers under hydraulic head.