The San Diego County Water Authority’s Board of Directors in July 2019 approved a contract to study the viability of a new regional conveyance system that would deliver water from the Colorado River to San Diego County and provide multiple benefits across the Southwest.
The $1.9 million contract was awarded to Black & Veatch Corporation for a two-phase study. The engineering firm conducted similar studies for the Water Authority dating back to 1996, but it looked at a “single use” in those studies.
A regional system to deliver San Diego’s independent Colorado River supplies from the Imperial Valley directly could be more cost-effective than the current system, while also providing multiple benefits for California and the Southwest. The study also will assess the potential for new regional and public-private partnerships and funding opportunities.
The Water Authority currently pays the Metropolitan Water District of Southern California to transport Quantification Settlement Agreement water through the Colorado River Aqueduct to San Diego.
The pipeline under study would be designed at a capacity to convey the QSA water, which in 2021 will reach its full amount of 280,000 acre-feet of water annually. The current Water Transfer Agreement between the Imperial Irrigation District and the Water Authority continues to 2047. But both agencies can agree to extend the transfer another 30 years to 2077.
Three potential routes for the pipeline will be considered as part of an initial screening of the alternatives during the first phase of the study – the Pipeline Alignment, the Tunnel Alignment and the Northern Alignment. (See graphic.) The study will also consider elements such as permit and environmental regulations, and risk, cost and economic analysis.
The first phase of the study, projected to cost $1.3 million, is expected to be completed in summer 2020. The Board will then determine whether to go forward with phase 2 of the study.
Pending Board approval, the second phase will include the final screening of alternatives based on refinement of site layouts, pipeline alignment and tunneling requirements, and risk, cost and economic analysis. The second phase will cost $590,000 and is expected to take one year to complete.