Groundwater Recharge Assessment Tool (Sustainable Conservation)
Flood Managed Aquifer Recharge (FloodMar) (Department of Water Resources)
A Technical Framework for Increasing Groundwater Replenishment (Association of California Water Agencies)
Recharge is an important component of sustainable groundwater management, as increasing the amount of recharge can help improve conditions in overdrafted basins and facilitate additional pumping in basins not experience chronic declines in groundwater levels.
Infiltration of rain and snowmelt and leakage from rivers and lakes recharge aquifers naturally. Thus protecting headwaters and other natural recharge areas is important for aquifer health.
Water for artificial recharge can come from many different sources, such as surface water, stormwater runoff, recycled water, or remediated groundwater. Geology permitting, this can then be recharged into the aquifer by way of percolation basins, canals, natural drainages, injection wells, or conjunctive use.
Groundwater recharge is also known as Managed Aquifer Recharge (MAR), Aquifer Storage and Recovery (ASR), or Flood MAR. While there are nuances between the definitions of the different terms, they all refer to the general practice of storing water in an aquifer for recovery later on.
Using aquifers to manage and store water below ground is not a new idea. Managed recharge programs have been in place for decades in Orange County, Santa Clara Valley, Kern County, and many of other regions in the state. It is an important tool for sustainable groundwater management and recovery from groundwater depletion. The ability in wet times to store water underground in dry years is central to the ability to conjunctively manage groundwater and surface water supplies.
Not all sites are suitable for groundwater recharge. When embarking on a groundwater recharge project, agencies should at a minimum consider subsurface geology, conveyance to the site, permitting, water rights, project funding, source water quality and long-term site management.
Groundwater Recharge Assessment Tool (GRAT)
Sustainable Conservation's GRAT tool allows you to identify and prioritize the most cost-effective on-farm recharge projects and operations.
- GRAT Fact Sheet
- GRAT website
- Map Viewer
- Guidance in establishing on-farm recharge sites for groundwater basins
- Guidance for on-farm recharge
- All Sustainable Conservation groundwater recharge resources
Flood Managed Aquifer Recharge (FloodMAR)
“Flood-MAR” is a management strategy being studied by the Department of Water Resources that uses flood water resulting from, or in anticipation of, rainfall or snowmelt for managed aquifer recharge (MAR) on agricultural lands and working landscapes.
More groundwater recharge resources
The Environmental Defense Fund, Point Blue Conservation Science, Audubon California and Sustainable Conservation developed a guide for how to build a recharge basin that provides operational benefits to basin managers while also creating valuable waterbird habitat. Building multi-benefit recharge basins
Crops like rice, corn, and alfalfa provide over a million and a half acres of potential habitat when managed for multiple-benefits. Waterbird use of flooded habitats depends primarily on the depth and timing of flooding, and the extent and height of vegetation. Guide to On-farm Recharge and Waterbird Habitat
Managed Aquifer Recharge (MAR) projects can provide benefits to many GDEs including wintering shorebirds, fisheries and riparian habitats. These case studies show how to facilitate multiple streams of funding to implement multi-benefit recharge projects. Multi-Benefit Groundwater Recharge Case Studies
Water Rights and Permit information
Depending upon the parameters of the recharge project, you may or may not need to obtain a water rights or other permits from the State Water Board.
- Flood Control, Groundwater Recharge, and Water Rights
- Purposes of Use for Underground Storage Projects
For more information, visit these webpages at the State Water Board:
Protection of Recharge Areas
Protecting natural recharge areas helps to maximize natural recharge to groundwater basins, provide flood protection, and improves water quality.
For more information:
- Protection of Recharge Areas: Resource Management Strategy (DWR)
- Map of Hydrologically vulnerable areas (State Water Board)
Explore groundwater recharge at the California Water Library