Tulare Lake

The Central Valley Project - Federal or State?

University of California, Berkeley (UC Berkeley) | June 1st, 1955

The Definition of Environmental Justice and the Designation of the California Office of Planning and Research as Coordinating Agency for Environmental Justice

State of California | November 18th, 2019

The Economic Impacts of Central Valley Salinity

California State Water Resources Control Board (SWRCB) | March 20th, 2009

The study team was charged with measuring the economic impacts of increasing salinity in the Central Valley to the year 2030. The study was conducted assuming that there

The study team was charged with measuring the economic impacts of increasing salinity in the Central Valley to the year 2030. The study was conducted assuming that there is no change in current policy and, as such, represents the economic impacts associated with taking no action. Additionally, the study was conducted on an aggregate valley-wide basis that required averaging the effects of salinity and, in some cases, costs. The growth in salinity in the Central Valley was based on two factors. The first factor was the growth of the areas of shallow saline groundwater based on 30 years of historical records. The second factor was increased levels of salts that result indirectly from imported water. Based on increasing salinity stemming from these factors, the direct economic effects on industry, residential, food processing, confined animal operations, and irrigated agricultural production in the Central Valley were measured. Economic and physical effects were quantified using different physical and economic models. In addition, the team undertook a substantial survey of the population in the Central Valley to establish non-market values for increased salinity and its effect on non-market activities. The study results showed that if salinity increases at the current rate until 2030, the direct annual costs will range from $1 billion to $1.5 billion. Total annual income impacts to California will range between $1.7 billion to $3 billion by 2030. The income impacts to the Central Valley will range between $1.2 billion and $2.2 billion.  The production of goods and services in California could be reduced from $5 billion to $8.7 billion a year. The Central Valley output reduction would range between $2.8 billion to $5.3 billion. Furthermore, there is $145 million per year of non-market costs. In terms of job losses the increase in salinity by 2030 could cost the Central Valley economy 27,000 to 53,000 jobs. California could lose 34,000 to 64,000 jobs. In short, the problem is substantial and growing steadily. The magnitude of the economic and employment losses justifies a more detailed study of remedial action and correction policies.

The Economic Value of Carryover Storage in California’s Water Supply System with Limited Hydrologic Foresight

University of California, Davis (UC Davis) | July 1st, 2021

The security and prosperity of California’s economy depend on a large, interconnected and highly engineered water supply system with vast surface and groundwater stora

The security and prosperity of California’s economy depend on a large, interconnected and highly engineered water supply system with vast surface and groundwater storage operated for over-year storage. Substantial public investment is needed to maintain and improve these systems with changing climate risks, increasing demands, and aging infrastructure. Hydro-economic optimization identifies promising opportunities for managing such systems, but scientific and engineering advances are needed to better incorporate hydrologic uncertainty and conjunctive management of streams and aquifers into such models. Over two decades of research the California Value Integrated Network (CALVIN) linear programming hydro-economic model has yielded insights for California’s inter-regional water system on many fronts, including climate change, groundwater sustainability, conjunctive management in southern California, water markets, and reservoir operations in Northern California. Yet there remains unrealized potential to improve the model’s formulation to better represent inter-annual hydrologic variability while concurrently developing reservoir control rules. To address this gap, this study implements linearized quadratic carryover storage value functions on 26 surface reservoirs and linear groundwater storage penalties on 32 groundwater reservoirs to optimize California’s inter-regional water system seasonal and inter-annual operations with limited seasonal foresight. A convex Pareto front tradeoff between total system cost and groundwater overdraft is developed through multi-objective evolutionary optimization of inter-annual carryover storage penalties. Resulting over-year storage valuations span a wide range of nearoptimal reservoir operations, suggesting substantial system flexibility and adaptability when managed in an integrated way. Generalized relationships between carryover capacity, carryover use, and the marginal value of carryover storage are drawn for the multi-reservoir system. When compared to carryover operations based on California’s current simulation model, CalSim-II, the performance of these near-optimal reservoir operations suggests room to improve currently prescribed reservoir control rules, especially in supporting more  sustainable conjunctive management with aquifers. Overall, this study demonstrates the practicability, feasibility, and utility for understanding large-scale integrated multi-reservoir conjunctive use systems using limited foresight with explicit carryover storage values.

The Economic Value of Efficiency for California Water Service: Lower Water Bills

Alliance for Water Efficiency (AWE) | June 28th, 2024

Prior to 2009, California Water Service Company (Cal Water) did not meter all its water customers, did not have conservation rates, and did not offer a robust set of cons

Prior to 2009, California Water Service Company (Cal Water) did not meter all its water customers, did not have conservation rates, and did not offer a robust set of conservation programs. Per capita water use had been flat or increasing prior to this period. In 2009, Cal Water adopted conservation rate designs (increasing block rates, IBRs), increased conservation program expenditures by more than three-fold and implemented an accelerated schedule to convert unmetered customers to metered water service. Per capita water demand has decreased steadily since 2009. These innovative strategies related to water efficiency, conservation, and rates over the years pose the questions: What would the economic impact on bills have been if none of these activities occurred? Are bill-paying customers better or worse off?

The Economy of the State Water Project

California Department of Water Resources (DWR) | December 14th, 2023

The State Water Project (SWP) is among the world's most extensive water conveyance projects, featuring a 705-mile-long network of dams, reservoirs, hydroelectric faciliti

The State Water Project (SWP) is among the world's most extensive water conveyance projects, featuring a 705-mile-long network of dams, reservoirs, hydroelectric facilities, pumping plants, and canals. The State Water Project plays a key role in the state’s economy. It supplies over 27 million Californians, a majority of the state’s population, along with commercial and industrial customers, including in the technology and manufacturing sectors, that account for a majority of the state’s economic activity. Project deliveries also supply water to the agricultural sector, supporting the cultivation of fruits, vegetables, and nuts, particularly in the Central Valley, the nation’s most productive agricultural region. This reliable water source not only ensures the livelihood of residents, businesses, and farmers but also contributes significantly to the state’s economy through technology, manufacturing, and agricultural exports. This report consolidates publicly available data from the California Department of Water Resources (DWR) and other agencies to provide policymakers with a comprehensive overview of the economy that is supported by the State Water Project.

The Effect of Declining Groundwater Levels on Supply Well Operations

University of California, Davis (UC Davis) | August 15th, 2016

This report explores the impact of droughts on domestic and irrigation well operations. Well completion reports and groundwater depth data obtained from the Department of

This report explores the impact of droughts on domestic and irrigation well operations. Well completion reports and groundwater depth data obtained from the Department of Water Resources were used in the analysis. The percentages of wells in which the top, middle or bottom of the screened interval became exposed above the pumping water level were calculated and implied maintenance or replacement costs were estimated. Increases in pumping costs from greater depths to groundwater were estimated as well. For our case study, we selected a 27 square mile area in Tulare County, where the California Department of Water Resources has determined that groundwater is in a state of critical overdraft and designated the basin as High Priority under the Sustainable Groundwater Management Act. Results indicate that for the 2015 drought, there was significant potential for incurring well maintenance and replacement costs as a result of drought conditions and water levels approaching critical points in the screened intervals. While the assumptions associated with the current method appear to result in overestimation of impacts, the current drought may have resulted in several million dollars in well maintenance and replacement costs. For irrigation wells that remained in operation, increased depths to groundwater would increase overall pumping costs. About $5.31 per acre ($1.7 per acre-foot) were estimated as increased pumping costs in the recent 2012-2015 drought. While these costs are not large on a per acre basis, they may be significant when incurred across large agricultural areas. This proof of concept analysis highlights the value of information on groundwater levels and well constructions for estimating impacts of droughts on long term groundwater pumping capacity and operation. This analysis can be extended for the entire Central Valley in an effort to quantify the impacts of drought and the importance of groundwater management.

The effects of aquatic area abundance, buffer, and hydrology on depressional wetland condition based on CRAM

San Francisco Estuary Institute (SFEI) | April 1st, 2016

The Essential Role of Local Context in Shaping Risk and Risk Reduction Strategies for Snowmelt-Dependent Irrigated Agriculture

American Geophysical Union (AGU) | June 11th, 2024

The evolution of dam induced river fragmentation in the United States

Nature Portfolio (Springer Nature) | June 28th, 2023