Expanding opportunities to recharge groundwater will require new surface storage and infrastructure to store and convey water to recharge areas, according to the latest state water plan update from the California Department of Water Resources (DWR).
Responding to comments that previous water plans lacked critical information on groundwater, DWR made the condition of the state’s groundwater basins the focus of the update released April 16.
In a foreword to the report, DWR Director Mark W. Cowin notes that the California Groundwater Update includes a “foundational set of data and analyses” of the state’s groundwater basins, well infrastructure, monitoring efforts, aquifer conditions and management practices.
Groundwater: The New Frontier
Unlike almost all other Western states, California never has had a comprehensive system for regulating groundwater. A body of common law grew that governs extraction and use of groundwater.
Management generally was in the form of plans developed by local agencies that focused primarily on gathering information. Farmers and other groundwater users have pumped at will without having to obtain government approvals.
The historic legislative package adopted in 2014 attempts to create such a comprehensive groundwater management system.
The Groundwater Update pulls together information about groundwater from a variety of sources, including the following observations:
• California groundwater basins contribute about 38% of the state’s total water supply in average years, but up to 46% in dry years.
• Many communities throughout the state rely on groundwater for all their water supply needs.
• Some of California’s groundwater basins have been managed sustainably for several decades, but others have not.
• Recent evaluations of high-use groundwater basins have documented significant declines in groundwater levels, degraded groundwater quality and increases in land subsidence.
• The state’s demand for and reliance on groundwater will continue to increase due to population growth, climate change, ecosystem and instream flow requirements, and a trend toward growers planting crops that depend on groundwater.
The report notes that changing how groundwater data is collected, shared, evaluated and reported is one key to improving groundwater management practices in the state.
Answering fundamental questions about the sustainability of groundwater supply and use requires “a regular, consistent and committed cycle of data collection, reporting, and assessment,” the report states.
The report’s recommendations include:
• Transparency by all state agencies, opportunities for public participation and accessible, user-friendly processes for making groundwater data available to the public to ensure policy and management decisions are based on the best scientific data available.
• Local agencies and regional water management groups should continue to work together to create effective groundwater sustainability agencies while setting local/regional priorities for groundwater planning, infrastructure and recharge programs.
• Expanding opportunities for groundwater recharge will require better hydrogeological studies of basins and new surface storage and infrastructure to store and convey water to recharge areas.
• The state should provide available funding, technical support and necessary guidance, but it is the responsibility of local agencies “to ensure that groundwater resources are sustainably managed at the groundwater basin level to collectively provide for California’s diverse agricultural, urban, and natural resource needs.”
The report notes that it will take “years to achieve the ultimate goal of local sustainable groundwater management at a statewide scale.”