The San Diego region will benefit from a historic water conservation-and-transfer agreement with the Imperial Irrigation District at least through 2047 after the San Diego County Water Authority’s Board of Directors took action Thursday to ensure deliveries of those supplies for an additional decade.
The Board voted unanimously to extend an Exchange Agreement with the Metropolitan Water District of Southern California by 10 years, requiring MWD to continue transporting conserved IID water to San Diego County through 2047. This year, about 20 percent of the San Diego region’s water is from the Water Authority’s conservation-and-transfer agreement with IID, and the volumes will continue to grow until 2021.
By extending the Exchange Agreement with MWD, the Water Authority gains 2 million acre-feet of conserved Colorado River water for delivery to the San Diego region between 2037 and 2047. Without that water, the San Diego region could face significant supply shortages during future dry years.
“Our independent Colorado River water supplies are a key component of the ongoing effort to develop our diversified and more reliable water supply portfolio,” said Mark Muir, chair of the Water Authority’s Board. “Using that conserved water helps fuel our economy and maintain our quality of life – and it has proven particularly valuable during droughts when less reliable supplies from MWD have been reduced.”
Thursday’s Board action was necessary because of mismatched terms in the Transfer Agreement with Imperial Irrigation District and the related Exchange Agreement with MWD. While the initial term of the Transfer Agreement with IID was 45 years (2003-2047), the Exchange Agreement with MWD had an initial term of 35 years (2003-2037). Through the end of 2017, the Water Authority has the unilateral discretion to extend the Exchange Agreement by 10 years so that it aligns with the Transfer Agreement, or to end the transfer 10 years early, so that it aligns with the Exchange Agreement.
Water transferred from IID is highly reliable due to IID’s senior water rights on the Colorado River. The Water Authority’s analysis shows that the price paid by the Water Authority for conserved IID water is competitive with what the Water Authority pays for each acre-foot of MWD untreated water.
Since 2003, increasing volumes of water conserved in the Imperial Valley have been delivered each year to San Diego County under the Transfer Agreement between the Water Authority and IID. That agreement is rooted in the historic 2003 Colorado River Quantification Settlement Agreement, which helped reduce California’s use of the river to its basic annual apportionment of 4.4 million acre-feet largely through water conservation-and-transfer agreements. The Water Authority’s Exchange Agreement with MWD governs deliveries of the conserved Colorado River water to the San Diego region, since MWD owns the only facility that can deliver these supplies to the Water Authority – the 242-mile-long Colorado River Aqueduct.
Under its agreement with IID, the Water Authority funds water conservation measures in the Imperial Valley. The Water Authority also pays MWD for transporting the conserved supplies to San Diego County. In 2021, the transfer ramps up to 200,000 acre-feet of water annually – approximately one-third of San Diego County’s water supply that year – and will remain at that level through the remainder of the agreement.
The Water Authority retains an option for a 30-year extension of the Transfer Agreement with IID – to 75 years overall – if both agencies agree. In addition, the Water Authority is assessing potential future water conveyance options that don’t depend on MWD – specifically, the cost and feasibility of building its own aqueduct from the Imperial Valley. While a new conveyance facility would be a significant investment, it could deliver significant benefits, such as transporting conserved water from IID through 2077, if the Transfer Agreement is extended for an additional term. The conveyance facility could also transport water conserved by the lining of the All-American and Coachella canals. The Water Authority receives approximately 80,000 acre-feet a year for 110 years under a contract with the U.S. Department of the Interior.