Abstract
Water exports from California’s Sacramento–San Joaquin Delta are an environmental concern because they reduce net outflows of fresh water from the Delta, and can entrain fish and disrupt flows within the Delta. If exports were no longer pumped from within the Delta, the regulatory issue becomes one of maintaining appropriate flows into and out of the Delta. This paper presents the results of two sets of hydro-economic optimization modeling runs, which were developed to represent a range of modified Delta operations and their economic and operational effects on California’s water supply system. The first set of runs represents decreasing export capacity from the Delta. The second set increases minimum net Delta outflow (MNDO) requirements. The hydro-economic model seeks the least–cost statewide water management scheme for water supply, including a wide range of resources and water management options. Results show that reducing exports or increasing MNDO requirements increase annual average statewide water scarcity, scarcity costs, and operating costs (from greater use of desalination, wastewater recycling, water treatment, and pumping). Effects of reduced exports are especially concentrated in agricultural communities in the southern Central Valley because of their loss of access to overall water supply exports and their ability to transfer remaining water to southern California. Increased outflow requirements increase water scarcity and associated costs throughout California. For an equivalent amount of average Delta outflows, statewide costs increase more rapidly when exports alone are reduced than when minimum outflow requirements are increased and effects are more widely distributed statewide.
Highlights
The costs and flexibility of water systems adapting to changes in environmental regulations is an important policy and planning issue
The Task Force and others acknowledged that upstream diversions from the Sacramento and San Joaquin river watersheds are a significant drain on Delta flows and should contribute to providing additional flows into the Delta (Lund and others 2007, 2010)
This paper explores the implications of these two regulatory strategies—export restrictions and minimum net Delta outflows (MNDOs) increases—for California’s economy and for water users in different parts of the state
Summary
The costs and flexibility of water systems adapting to changes in environmental regulations is an important policy and planning issue. Operating costs (including desalination, water treatment, recycling, and pumping) rise with export restrictions, moving from $2.4 billion per year under base conditions to $2.6 billion per year without exports (Table 2). These increases are driven by the use of more costly supply alternatives, such as desalination and wastewater reuse, and reduced hydropower production. There is some scarcity —just below 3.7 BCM per year —because availability, conveyance and infrastructure capacity, and the cost of additional supplies prohibits some users from obtaining all the water they could economically put to use (Table 3). Urban areas could benefit somewhat from diverting more fresh water into their aquifers for storage, when capacity is available
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
