Sunrise light on a grove of tufa towers emerging from the water of Mono Lake with soft green and dusty-red wild grasses in the foreground, Canada geese in the shallow water with reflections of the rocky towers, and desert hills in the distance.

Revised water license for DWP on the horizon: State Water Board expects finalization in 2020

Over the past year, the California State Water Resources Control Board has been effectively advancing the long-running project of revising the Los Angeles Department of Water & Power’s (DWP) water license to include a set of next-generation stream restoration requirements agreed to in the Mono Basin Stream Restoration Agreement with the Mono Lake Committee.

Mono Lake’s tributaries will get streamflows that better mimic natural runoff patterns when DWP’s water license is amended to reflect the 2013 Mono Basin Stream Restoration Agreement. Photo by Andrew Youssef.

Signed in fall 2013, following 15 years of stream studies and three years of intensive legal negotiations, the Agreement was a significant milestone for Mono Lake. It marked the completion of a major area of study required by the State Water Board and the launch of a new period of restoration at Mono Lake in which the Los Angeles Aqueduct serves the new additional purpose of healing streams. In this new era, the important ecological, wildlife, scenic, and economic values of Mono Lake and its tributary streams will be recognized equally alongside the water needs of Los Angeles.

Persistence pays off

In the years since signing the Agreement, the Committee has maintained constant pressure on the process through gentle prodding, helpful support, conference calls, additional technical analysis, letters from lawyers, and persistent communication with every party involved. Some delay is understandable, but the Committee has never lost the sense of urgency to move forward, given how important the Agreement’s new streamflow specifications are for stream restoration success.

In the last year, monthly progress checks and a clear vision of the schedule and goal have kept the license revision process on track. Soon the State Water Board will seek public input on the license terms, which will be a key opportunity for Committee members to offer support for the process. Before summer, DWP is scheduled to deliver its long-promised environmental review document describing the Grant Lake Reservoir Outlet construction project and associated streamflow changes.

Full implementation of new SEFs

At the heart of the Agreement are Stream Ecosystem Flows (SEFs) that mimic natural runoff patterns and activate the natural processes that will continue the restoration of Mono Basin streams. SEFs are the engines that run effective stream restoration—affecting everything from fish growth and population health to the regeneration of robust multi-storied streamside forests. A tremendous amount of study, monitoring, and modeling has been done to inform the new flow recommendations, which mimic streamflows in the wide range of possible year types and runoff scenarios. Thus, the implementation of SEFs is the single most important action necessary for stream restoration.

Thanks to Committee pressure on DWP, temporary delivery of SEFs began in 2019. Although high flows in Rush Creek can’t be achieved until the Grant Outlet is constructed, the rest of the Rush Creek flow pattern can be delivered along with the SEFs for Lee Vining, Parker, and Walker creeks.

Grant Dam outlet

Peak flows on Rush Creek are currently impossible to deliver due to the aqueduct’s World War II-era infrastructure that was built with the purpose of total stream diversion. In particular, the problem is that the dam at DWP’s Grant Lake Reservoir was constructed without an outlet, reflecting the outdated expectation that the entire flow of Rush Creek would be continuously diverted into the aqueduct.

Crucially, the Agreement includes a commitment to construct an outlet. A pair of 12-foot-tall Langemann gates will be installed in an excavated notch in the reservoir spillway. The outlet will ensure that at least 750 cubic feet of water per second can move out of Grant Reservoir into Rush Creek in the wettest years—a volume similar to the natural snowmelt peak at such times.


The Monitoring Administration Team (MAT) will oversee and manage annual budgeting and contracting for stream, fishery, lake, and waterfowl monitoring. The team will be made up of DWP, the Committee, the California Department of Fish & Wildlife, and CalTrout. DWP will fund a comprehensive list of monitoring tasks—and several previously-ordered restoration actions—at specified levels, and the team will ensure efficient implementation.

The MAT will also oversee the adaptive management restoration process in order to apply the knowledge learned through scientific monitoring for better stream recovery.

New era of restoration

Efforts with outcomes of this magnitude take focused time, energy, and public support. In the end, the new water license will be a symbol of how science-based analysis combines with principled policy negotiations to forge a path to healthier, more resilient streams and habitats at Mono Lake.

Speak up for Mono Lake

In the coming months there will be times when we need concerned citizens to speak up for Mono Lake again. Soon the State Water Board will seek public input on the license terms, which will be a key opportunity for Committee members to offer support for the process. Please make sure we have your email address so we can let you know when public input is needed.

This post was also published as an article in the Winter & Spring 2020 Mono Lake Newsletter (pages 4 & 24).