Water Budget Calculator
Calculate the water balance for a watershed or region. Determine storage change from precipitation, evapotranspiration, runoff, and groundwater outflow.
Inputs
Results
Storage Change (ΔS)
150 mm
Budget Status
Surplus
How to Use This Calculator
- Enter Precipitation, Evapotranspiration, and Surface Runoff.
- Set Groundwater Outflow.
- Review Storage Change (ΔS) (mm) and Budget Status.
- Use ET (% of Precip) and Runoff (% of Precip) to inform your decision.
- Use the chart to visualize the results and explore different scenarios by adjusting inputs.
Formula
ΔS = P - ET - R - GW_outRelated Calculators
Groundwater Recharge
Estimate annual groundwater recharge from precipitation, runoff coefficient, and evapotranspiration using the water balance method.
Evapotranspiration Calculator
Estimate reference evapotranspiration (ET₀) using a simplified Penman-Monteith approach from temperature, humidity, wind speed, and solar radiation.
Watershed Area Calculator
Calculate drainage area and morphometric parameters of a watershed from perimeter, shape factor, and longest flow path.
SCS Curve Number
Calculate runoff depth using the USDA SCS (NRCS) Curve Number method. Determine runoff, infiltration, and initial abstraction from precipitation and curve number.