CalFed and Groundwater
The CalFed Draft Programmatic Environmental Impact Statement/Environmental Impact Report (DEIR) has been released. Comments are due by June 1, 1998. The following are direct quotes or summaries from the groundwater section of the DEIR and do not necessarily reflect the views of GRA or its members.
According to the DEIR, there are three general types of potential programmatic-induced impacts on groundwater resources.
Summary of Impacts to Groundwater Resources
No Action would lead to increased groundwater use and potential adverse impacts
Alternatives 1, 2, and 3 are expected to provide additional surface water and groundwater storage that will potentially reduce the significant adverse impacts to groundwater resources throughout all regions.
Ecosystem restoration, water quality, and levee programs would increase groundwater recharge.
Potential adverse impacts due to reduction in groundwater recharge from water use efficiency and water transfer program elements.
Under the no action alternative, increased demand for water combined with constraints on water supply are expected to cause an increase in groundwater use in all regions, leading to potentially significant declines in groundwater levels, possible degradation of water quality, and subsidence in some basins. These effects are expected to be most widely felt in the San Joaquin River Region and in the SWP and CVP Service Areas outside the Central Valley. Local effects will probably occur in the Sacramento River Region, although subsidence is not expected there. In the Bay Region, significant declines in water levels are likely to occur, but for the most part, are not expected to cause problems. In the Delta Region no significant change in groundwater levels is expected.
Storage and Conveyance
Alternative 1, 2 & 3. Additional surface water and groundwater storage have the potential to reverse the adverse effects on groundwater anticipated under the No Action Alternative.
Water Transfers could improve the distribution of water and reduce reliance on groundwater in some areas. Adverse impacts could occur if the transfers induce growth. Groundwater substitution transfers may contribute to overdraft, may directly affect accretion to or depletion from streams, may result in subsidence, and may increase pumping costs for other groundwater users.
Ecosystem Restoration Program would probably impact groundwater indirectly through its effects on surface water. Reductions in surface water may lead to increased use of groundwater. Beneficial impacts are expected due to increased groundwater recharge from increased stream flows in the Sacramento and San Joaquin River regions.
Coordinated Watershed Management is expected to have beneficial impacts on groundwater quality and reverse local declines in groundwater levels in upper watershed areas.
The pertinent features of the regulatory framework of groundwater management are:
California landowners have correlative rights to extract as much groundwater as they can put to beneficial use. The state does not have statutory authority to manage groundwater, and no systematic statewide groundwater management program exists.
Only a small fraction of the stateÕs groundwater is actively managed under a formal program. AB 3030 allows certain local agencies to manage groundwater. Cities and counties may adopt ordinances to manage groundwater, but this has not occurred.
Twelve groundwater management districts have been established through special legislation.
In some basins, disputes over groundwater pumping have been adjudicated by the courts.
Conceptual Mitigation Strategies
Mitigation strategies to prevent groundwater level declines could include creating additional surface or groundwater storage facilities to meet demand without overdrafting, importing water from other basins, purchasing water rights from willing sellers, regulating groundwater withdrawals to not exceed perennial yields, reducing demand through conservation or increasing recharge by restoring floodplains.
Mitigation strategies to reduce or prevent adverse impacts from water transfers include setting appropriate basin objectives, preparing basin management plans to meet those objectives, providing regulatory support and oversight, providing incentives for controlling demand, and specifying corrective actions when objectives are not met.
For more information contact CalFed at (800) 900-3587.