ACWA Study Highlights New Approaches to Water Storage by Emily Allshouse Aug 7, 2017 Water News ACWA has released a technical study that highlights how investments in 21st century water infrastructure could provide tools to bring much-needed resiliency and flexibility to California’s water supply system. The study by MBK Engineers modeled real-world capabilities of several proposed storage projects. The findings suggest that adding storage assets to the system and operating them in an integrated way would result in significant value, including new water available to meet the coequal goals of improving ecosystem health and water supply reliability, enhanced groundwater recharge capabilities, protection of existing water supplies, and a more resilient water system for both the environment and water users. The study and an eight-page briefing piece are available on ACWA’s website here. The first-of-its-kind study is intended to spark discussion about a new approach to water storage integration as the California Water Commission conducts its public process to allocate $2.7 billion from Proposition 1 to help fund water storage projects. Among the key conclusions: Water is available. There are periods in most years (even during dry years) when runoff in the Bay-Delta watershed is far greater than that needed for regulatory requirements and water rights. During periods of abundance, a fraction of this available water could be stored to benefit both water supply and ecosystem management during dry times. System carryover storage can be enhanced significantly. Adding diverse new surface and groundwater storage projects would enhance the state’s ability to take advantage of water available after all regulatory requirements and water rights have been met. Better managing the timing, location and function of those flows could help meet multiple objectives and increase end-of-year carryover storage by as much as 1.9 million acre-feet (MAF). Operational flexibility can be increased. Integrating the operation of new storage projects with the state’s existing infrastructure would add much-needed flexibility to the system, particularly enhanced timing and coordination of storage releases to meet the coequal goals of improving water supply reliability and ecosystem health. More water can be put to use for the environment and water users. Integrated operation of storage could increase water available for the environment and for water users by 400,000 acre-feet on average and by up to 800,000 acre-feet on average if Delta conveyance improvements also are made. Groundwater management can be enhanced. Integrated storage would enhance conjunctive use of surface water and groundwater, and significantly enhance the amount of water available for groundwater replenishment. Multiple benefits can be realized. Increased carryover storage resulting from integration would have multiple operational benefits, including increased cold water available for fish, improved habitat for fish and wildlife, recreation, increased hydropower generation, and water supply reliability. Resiliency is added to the system. Investments in integrated storage and improved conveyance would inherently reduce conflicts in the system, adding resilience to the system and protecting against further losses of supply due to conflicts between water project operations and the environment. Questions may be directed to ACWA Director of State Regulatory Relations Dave Bolland at (916) 441-4545.