AWWA ACE70819

The San Diego County Water Authority has embarked upon a Capital Improvement Program to improve the pipeline delivery system and to make the method of supplying the water throughout the county more flexible. Included in the CIP is the Emergency Storage Project (ESP), which is a system of reservoirs, interconnected pipelines, and pumping stations, designed to make water available to all communities in the San Diego region in the event of an interruption of imported water deliveries due to an emergency such as an earthquake. An important component of the Water Authority's ongoing CIP is the Rancho Penasquitos Pressure Control/Hydroelectric Facility (RP PCHF) that not only increases water reliability, but also addresses energy reliability within the region. Located along a major aqueduct and connected to a 108-inch diameter untreated water pipeline, this dual purpose facility not only controls water pressure and flow but also generates renewable energy. A key feature of the RP PCHF is the single horizontal Francis type turbine which makes use of available hydraulic pressure to generate up to 4.5 MW of electricity. The RP PCHF is not only good for the environment by generating electricity without harmful emissions, but is also advantageous to the rate payers by generating approximately $1.1 million annually through the sales of electricity. This annual revenue will help to stabilize water rates for the ratepayers and offset the Water Authority's operations and maintenance expenses. The RP PCHF was designed and constructed for seismic reliability and operational flexibility. This paper presents a case study on the RP PCHF, focusing on how the Water Authority overcame project challenges to take advantage of an untapped energy source while improving water delivery reliability to the region. Includes figures.