Aquifer Recharge Calculator — Formula
## How to Calculate Aquifer Recharge
Aquifer recharge is the natural or managed process of water percolating into underground aquifers.
### Formula
**Recharge (acre-feet) = Area * Rainfall * Infiltration % / 12**
**1 acre-foot = 325,851 gallons**
### Typical Infiltration Rates
- Sandy soil: 40-80%
- Loam soil: 20-40%
- Clay soil: 5-15%
- Urban (impervious): 5-10%
Aquifer recharge is the natural or managed process of water percolating into underground aquifers.
### Formula
**Recharge (acre-feet) = Area * Rainfall * Infiltration % / 12**
**1 acre-foot = 325,851 gallons**
### Typical Infiltration Rates
- Sandy soil: 40-80%
- Loam soil: 20-40%
- Clay soil: 5-15%
- Urban (impervious): 5-10%
Exemplo Resolvido
100 acres of loam soil receiving 35 inches rainfall with 25% infiltration.
- Recharge: 100 * 35 * 0.25 / 12 = 72.9 acre-feet
- In gallons: 72.9 * 325,851 = 23,762,833 gallons
- Daily average: 23,762,833 / 365 = 65,103 gallons/day
- Homes served: 65,103 / 300 = 217 homes