Underground Sand Dam (Subsurface Dam)¶
Sand Dams & Civil Works • Est. CapEx: $500 USD • Lifespan: 30 Years (Standardized)
Technical Overview¶
A traditional low-tech water harvesting structure used in arid regions to intercept shallow groundwater or capture ephemeral rainwater beneath the surface. By storing water underground, it dramatically reduces evaporative losses compared to open surface reservoirs.
Key Specifications & Engineering Parameters¶
| Parameter | Specification |
|---|---|
| Category | Sand Dams & Civil Works |
| Capital Cost (CapEx) | $500 USD |
| Power / Energy | 100% Gravity / Zero Power |
| Target Scale | Community Scale |
| Standard Lifespan | 30 Years (Standardized) |
| Technology Maturity | Field Tested |
| Primary Mechanism | In one design, a trench is excavated across a natural groundwater or dry streambed path, a vertical impermeable barrier is inserted, and the trench is backfilled. In sandy terrain, a low masonry or concrete wall built across a valley traps coarse sand and water during floods; the accumulated sand layer overhead acts as an evaporative cap while storing water in the pore spaces below. |
Engineering Trade-Offs¶
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- Requires periodic community maintenance
- Site-specific hydrogeological constraints
Cross-Reference & Interactive Tools¶
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