Recharge is made up of four components.
  1. Precipitation recharge
  2. Groundwater return flows
  3. Surface water return flows
  4. Canal leakage

Precipitation Recharge

Annual precipitation at 34 stations is collected from the National Climatic Data Center (NCDC) TD3220 data sets. These point values of precipitation are then kriged to provide an annual precipitation distribution.

Recharge from precipitation is calculated as the annual precipitation distribution times the precipitation recharge curve for the soil type multiplied by the spatial multiplier.

A different recharge curve is used for irrigated lands vs. non-irrigated lands. Irrigated lands are made up of exclusively groundwater irrigated lands, exclusively surface water irrigated lands and commingled irrigated lands.

The result is the annual precipitation recharge distribution.

Return Flows and Canal Leakage

Groundwater return flows are calculated as a fraction of the groundwater pumping. Similarly surface water return flows are calculated as a fraction of the surface water diversions. Canal leakage is calculated by distributing canal leakage estimates along canals.

Annual Precipitation by Station
Annual Precipitation
Precipitation Recharge Curves
Precipitation Recharge Soil Types
Precipitation Recharge Spatial Multiplier
Irrigated Acreage
Groundwater Irrigated Acreage
Surface Water Irrigated Acreage
Commingled Irrigated Acreage
Annual Precipitation Recharge
Annual Groundwater Recharge
Annual Surface Water Recharge
Annual Canal Recharge
Annual Total Recharge
Monthly Groundwater Recharge
Monthly Surface Water Recharge
Monthly Canal Recharge
Monthly Total Recharge
Home | Previous | Next

Data Files
Well Pumping
County Summaries
Head Change
Predicted Impact