Owens River Gorge Flow Restoration Project Completes Decade-Long Order

By Jessica Johnson

The Owens River Gorge looks like a miniature Grand Canyon, with its steep-sided canyon and unique rock formations, and spans 10 miles along the upper Owens River in the Eastern Sierra. With an impressive 2,300-foot drop, the Gorge not only has the capabilities of supplying hydro power, but offers exceptional recreation opportunities for fishing, hiking and rock climbing. With construction of all Owens Gorge Power Plants completed, channel maintenance flow started in early September 2019 where a total of approximately 680 cubic-feet per second of water flowed through the Upper, Middle and Control Gorge. (Middle Gorge pictured).

Making up four percent of the Los Angeles Aqueduct length, the Gorge contains three LADWP hydroelectric facilities that were constructed in the 1940s: the Upper, Middle and Control Gorge power plants. These three power plants help supply 41 percent of LADWP’s hydro power, and provide 100 percent of the power to LADWP customers in Bishop, Big Pine and Independence.

After a penstock break in 1991, concerns about water flow and fish habitat in the Gorge began to grow and led to decades of legal battles. This resulted in an agreement between LADWP and California Fish and Wildlife requiring a permanent peak flow to protect fish life and overall ecosystem health. LADWP began to implement the Owens River Flow Restoration Project in 2014, with the goal of helping to establish a healthy fishery and a riparian corridor (the area of unique vegetation growing near the river) for wildlife use as well as supporting habitat life for native species. “This project has a complex history, which is often the case with the storied history of the Owens Valley,” said Robert Fick, Manager of Hydro and Renewables, and High Voltage and Substations for LADWP’s Power Supply Operations Division. “In order to successfully meet the requirements, we had to do a lot of research and work closely with LADWP systems and state agencies.”

The project was a joint effort among almost 70 employees, led by Northern District Aqueduct Operations and Power Generation Station Electric Engineering. The Power System divisions primarily worked on the construction needs for the project, including the flow measurement stations and spillway, and reinforcing power poles and roads. The Water System led the design and installation efforts for the flow measurement equipment and data collection, which included posting real time data on LADWP’s website. Construction was completed in August 2019, and the first scheduled “channel maintenance flow” to the river between Upper Gorge Power Plant and Pleasant Valley Reservoir went successfully in September 2019.

“To get so many different groups from throughout many LADWP divisions to work together under such tight time constraints, and have the results turn out so well is an amazing accomplishment,” said Eric Tillemans, Water Operations Supervisor and a project manager for the Water System.