Facing the threat of Colorado River reservoirs reaching critically low levels after nearly 20 years of drought, California water agencies stepped up in 2019 to help ensure the river will continue to provide a reliable supply of water to the Southwest in the coming decade.
Under the Drought Contingency Plan, California along with Arizona and Nevada agreed to store defined volumes of water in Lake Mead, largely through conservation, if the lake reaches certain levels. California would make DCP storage contributions if Lake Mead’s elevation drops to 1,045 feet above sea level. Those contributions—ranging from 200,000-350,000 acre-feet a year—would be shared by the Metropolitan Water District, Palo Verde Irrigation District and Coachella Valley Water District.
Related to the signing of the DCP in May, the Bureau of Reclamation approved new Intentionally Created Surplus exhibits for Metropolitan, which include descriptions of the type of conserved water that qualify for storage in Lake Mead, including water generated from turf removal and other conservation activities. With the approval of the new ICS exhibits, Metropolitan now has qualified programs to store up to the maximum amount allowed to California under current guidelines of 400,000 AF in any year. Given this increased flexibility, Metropolitan plans to maximize storage in Lake Mead and target storing the full 400,000 acre-foot annual limit.
Metropolitan and Bard Water District approved a new agreement to extend a seasonal fallowing program for seven years. The program will be in place from 2020- 2026, concurrent with the interstate agreement that allows Metropolitan to store water generated from the seasonal fallowing program in Mead. The agreement incorporates lessons learned from a two-year pilot program, making the program more efficient and effective.
In a major step toward the potential construction of one of the largest water recycling plants in the nation, Metropolitan and the Sanitation Districts of Los Angeles County began operations at the Regional Recycled Water Advanced Purification Center. The 500,000-gallon-per-day demonstration facility takes cleaned wastewater from the Sanitation Districts’ Joint Water Pollution Control Plant in Carson and purifies it using an innovative process that could significantly improve efficiencies and reduce costs in water recycling. The testing and other analyses will help the agencies determine whether to grow the facility to a full-scale plant that could potentially produce up to 150 million gallons of purified water daily—enough to serve more than 500,000 homes and industrial facilities, further reducing the region’s reliance on Colorado River water.
During the year, Coachella Valley Water District continued its rebate program to fund the costs of sealing uncontrolled flows from artesian wells and rebates to golf courses to replace turf with desert landscaping. CVWD offers a number of rebates to domestic water customers, which reduces groundwater pumping and protects the groundwater basin.
CVWD also continued to engage stakeholders in the development of new programs and efforts to reduce water demand. CVWD’s Agricultural Water Advisory Group, which includes representatives from the district, U.S. Department of Agriculture, Resource Conservation District, academia and agricultural customers, meets quarterly to discuss studies, regulations, customer service and ideas related to water use efficiency.
Since the inception of the 2003 Quantification Settlement Agreement and related agreements, which set in motion a number of ag-to-urban water conservation and transfer agreements, IID has conserved more than 5.3 million acre-feet of water. The district met this achievement while operating under an annual consumptive use cap of 3.1 million acre-feet, while going through its first full year of no agricultural land fallowing and while being judicially prevented from implementing a system to equitably distribute water.
Palo Verde Irrigation District completed its first year of a three-year deficit irrigation study to identify and optimize strategies that can enhance alfalfa forage production and sustainability while conserving water. The project aims to quantify the potential savings of water associated with deficit irrigation and evaluate the impact of those practices on alfalfa yields and the soil. Preliminary first-year results indicate that deficit irrigation strategies could conserve about 1 acre-foot per acre or more without a significant reduction in alfalfa yield. However, because alfalfa is a multi-year crop, any new practice may have a long-term impact, so more data is needed before making a firm conclusion from the study.