South Coast

A State Role in Supporting Groundwater Trading with Safeguards for Vulnerable Users: Findings and Next Steps

California Department of Water Resources (DWR) | May 18th, 2022

In those parts of California where groundwater pumping has long exceeded replenishment, people are striving to bring groundwater basins into sustainable conditions within

In those parts of California where groundwater pumping has long exceeded replenishment, people are striving to bring groundwater basins into sustainable conditions within 20 years, between 2040 and 2042, as the Sustainable Groundwater Management Act (SGMA) requires. In some areas, groundwater sustainability agencies (GSAs) – the local agencies tasked with sustainable groundwater management – are beginning to work with other entities and stakeholders to discuss and experiment with the idea of giving groundwater pumpers allocations – allowances to remove a certain amount of water from a groundwater basin – and allowing them to either use their allocation individually or trade allocations between specified parties. Ideally, groundwater trading could ease the economic disruption of cutting back the overall amount of water pumped from a groundwater basin; growers who have less need for pumping could sell their allocation to others willing to pay for it, helping buyers keep their operations functional while compensating sellers. But the concept of groundwater trading raises many questions: How would wetlands, streams, and other ecosystems fed by aquifers be treated in a groundwater trading program? Would operators of farms who lack the resources of larger neighbors be able to benefit from trading? How might trading affect people who depend upon a household well or communities that need reliable groundwater supplies for homes and businesses? How can GSAs work with local stakeholders to develop, implement, and oversee trading programs that help with sustainable groundwater management? There is a State interest behind all of these questions – and a clear need for a focused discussion about groundwater trading.

A western United States snow reanalysis dataset over the Landsat era from water years 1985 to 2021

Nature Portfolio (Springer Nature) | November 7th, 2022

Water stored in mountain snowpacks (i.e., snow water equivalent, SWE) represents an important but poorly characterized component of the terrestrial water cycle. The Weste

Water stored in mountain snowpacks (i.e., snow water equivalent, SWE) represents an important but poorly characterized component of the terrestrial water cycle. The Western United States snow reanalysis (WUS–SR) dataset is novel in its combination of spatial resolution (~500 m), spatial extent (31°–49° N; 102°–125° W), and temporal continuity (daily over 1985–2021). WUS–SR is generated using a Bayesian framework with model-based snow estimates updated through the assimilation of cloud-free Landsat fractional snow-covered area observations. Over the WUS, the peak SWE verification with independent in situ measurements show correlation coefficient, mean difference (MD), and root mean squared difference (RMSD) of 0.77, −0.15 m, and 0.28 m, respectively. The effects of forest cover and Landsat image availability on peak SWE are assessed. WUS–SR peak SWE is well correlated (ranging from 0.75 to 0.91) against independent lidar-derived SWE taken near April 1st, with MD

A.D. Edmonston Pumping Plant and Tehachapi Crossing

California Department of Water Resources (DWR) | October 1st, 1985

Achievements in Conservation, Recycling, and Groundwater Recharge Covering Fiscal Year July 2018-June 2019

Metropolitan Water District of Southern California (MWD) | March 1st, 2020

Achieving Groundwater Access for All: Why Groundwater Sustainability Plans are Failing Many Users

Groundwater Leadership Forum | July 3rd, 2023

California made a serious commitment to bring the most depleted groundwater basins back into balance when it passed the Sustainable Groundwater Management Act (SGMA) in 2

California made a serious commitment to bring the most depleted groundwater basins back into balance when it passed the Sustainable Groundwater Management Act (SGMA) in 2014. This commitment is being carried out at the local level through the formation of hundreds of new groundwater agencies, the launch of basin-level planning processes, and the creation of groundwater sustainability plans. This report summarizes the results of a scientific study published in Nature Communications. that analyzed the degree to which these groundwater plans equitably integrate and protect vulnerable groundwater users, and suggests course corrections in the ongoing SGMA process to ensure we are preparing our groundwater basins for a changed climate.

Achieving the Human Right to Water in California: An Assessment of the State's Community Water Systems

Office of Environmental Health Hazard Assessment (OEHHA) | January 15th, 2021

The Human Right to Water Framework and Data Tool (CalHRTW 1.0) provides a consolidated, stand-alone, quantitative assessment of baseline conditions in the quality, acces

The Human Right to Water Framework and Data Tool (CalHRTW 1.0) provides a consolidated, stand-alone, quantitative assessment of baseline conditions in the quality, accessibility and affordability of California’s drinking water. This assessment can help screen for drinking water challenges and analyze changes over time and complements existing cumulative impacts analyses (e.g., CalEnviroScreen (OEHHA, 2021b)) by providing information at a greater level of detail regarding drinking water.

Adaptability and adaptations of California’s water supply system to dry climate warming

Climatic Change (Springer) | November 27th, 2007

Economically optimal operational changes and adaptations for California’s water supply system are examined for a dry form of climate warming (GFDL CM2.1 A2) with year 2

Economically optimal operational changes and adaptations for California’s water supply system are examined for a dry form of climate warming (GFDL CM2.1 A2) with year 2050 water demands and land use. Economically adaptive water management for this climate scenario is compared to a similar scenario with the historical climate. The effects of population growth and land use alone are developed for comparison. Compared with the historic hydrology, optimized operations for the dry climate warming scenario raise water scarcity and total operation costs by $490 million/year with year 2050 demands. Actual costs might be somewhat higher where non-economic objectives prevail in water management. The paper examines the economical mix of adaptation, technologies, policies, and operational changes available to keep water supply impacts to such modest levels. Results from this screening model suggest promising alternatives and likely responses and impacts. Optimized operations of ground and surface water storage change significantly with climate. Dry-warm climate change increases the seasonal storage range of surface reservoirs and aquifers. Surface reservoir peak storage usually occurs about a month earlier under dry-warm climate change.

Adapting to Climate Change and Drought in Selected California Groundwater Basins: Local Achievements and Challenges

California Natural Resources Agency (CNRA) | August 27th, 2018

Climate change projections are for higher temperatures and extreme droughts by the end of the 21st century. This will alter the natural recharge of groundwater, including

Climate change projections are for higher temperatures and extreme droughts by the end of the 21st century. This will alter the natural recharge of groundwater, including decreased inflow from runoff, increased evaporative losses, and warmer and shorter winter seasons, impacts that are likely to exacerbate already existing groundwater overdraft in many basins. Additionally, the imported surface water that can be delivered from the Central Valley Project (CVP) and State Water Project (SWP) to areas reliant on this water for groundwater recharge and consumptive use is projected to be less reliable and more expensive. Yet groundwater is a critical water supply source during drought when it compensates for reduced surface water supplies. The need for proactive adaptation strategies to address the extreme droughts projected under climate change are frequently discussed, yet there are limited examples of such groundwater management strategies. This paper therefore explores:  1) How groundwater management agencies are planning for drought  2) What new approaches are currently being used that show promise for addressing the more extreme droughts projected under climate change? 

Adapting wastewater management systems in California for water conservation and climate change

Sustainable and Resilient Infrastructure (Taylor & Francis) | February 27th, 2023

Addendum to the State Water Project and Central Valley Project Drought Contingency Plan

California Department of Water Resources (DWR) | July 29th, 2022

This Addendum includes current hydrologic conditions, plus updates on the following: operations status and the latest SWP and CVP (collectively referred to as Projects) o

This Addendum includes current hydrologic conditions, plus updates on the following: operations status and the latest SWP and CVP (collectively referred to as Projects) operations forecasts; species status; and known WY 2022 drought actions.