After nearly a decade of intense work, our goal is within reach!

The Tuolumne River is on the brink of ecological collapse. The agencies responsible for managing our water supply are undermining their constituents’ values of revitalizing the stressed and over-worked River. We need your help to hold them accountable for their deceptive games.

        The San Francisco Public Utilities Commission (SFPUC) is spreading misinformation, and is doing so under the guise of prudence. They are deceiving politicians and agencies into putting pressure on the State Water Board so they will back down from improving instream flows through the Bay Delta Water Quality Control Plan (Bay Delta Plan). They have not been behaving like the environmental heroes they would like you to think they are.

        The SFPUC is using its might (budget, connections, etc.) to spread fear through misinformation. Fear that we cannot both protect the River and have a healthy economy; fear that leaving more water in the River is a wasted opportunity for economic development. Meanwhile, TRT has had to use what small stones we have to load our slingshot and make our voices heard. Help us load our slingshot to deal a final blow to this Goliath!


How can I get involved?

  1. Make a donation to Tuolumne River Trust today. Your donation supports our continued work on the Bay Delta Plan, which is our last best hope for reviving the Tuolumne and protecting it for generations to come.
  2. Attend an informational webinar. Register here to stay informed of upcoming BDP happenings:
  3. Educate yourself about the facts to avoid being misled by propaganda. See resources below.

Condensed Timeline

2009 – Delta Reform Act

2010 – Flow Criteria Report

2016 – Draft Substitute Environmental Document (SED)

Expected – Spring, 2018 – Final SED

Expected – Summer, 2018 – State Water Board Decision


I live in the Bay Area and keep hearing that my water comes from Hetch Hetchy. Why should I care about the Tuolumne River?

San Francisco has done a great job with their public information campaign to educate residents about the water system that delivers water from the Sierra to Bay Area  – the Hetch Hetchy Water System. What they fail to tell people is that the Tuolumne River is what fills the Hetch Hetchy Reservoir, making it the true source of your water.


What is the Hetch Hetchy Water System?

Hetch Hetchy is a reservoir. Reservoirs rely on dams to create an artificial lake where water from a river can be stored (and then diverted for human and agricultural use). The river that flows into Hetch Hetchy Reservoir is the Tuolumne River. The Hetch Hetchy Water System is what supplies Bay Area residents drinking water and power.


What is the Bay Delta Water Quality Control Plan, also referred to as the Bay Delta Plan?


The Bay Delta Plan (BDP) was required by the Clean Water Act.  The BDP was first implemented in 1978, and is supposed to be reviewed every three years.  The last time any major changes were made to the Plan was in 1995. Now, after more than 20 years, the Bay Delta Plan is being updated, making this a once-in-a-generation opportunity to revive the Bay-Delta and rivers that feed it.  The draft document for Phase 1 of the revised Plan calls for more freshwater inflow into the Bay-Delta, starting at 40% of unimpaired flow from the San Joaquin River’s three main tributaries — the Stanislaus, Tuolumne and Merced Rivers — between February and June, which is a critical time period for juvenile fish rearing and outmigration.


How does the Bay Delta Plan affect the Tuolumne River?

The new Plan calls for 40% of unimpaired flow (what would naturally flow down our rivers) between February and June on the lower San Joaquin and its tributaries: the Stanislaus, Tuolumne and Merced Rivers.  Currently, the three tributaries respectively see about 40%, 21% and 25% of their natural flow enter the San Joaquin. Flows could range from 30-50% depending on how successful non-flow measures (such as habitat restoration) are at reaching established goals and objectives.


Why are higher flows on the Tuolumne good for the river?

Higher flows will improve the ability of salmon and other fish to migrate to and from their natal streams to the ocean, reduce the concentration of river pollutants, and lower water temperatures.  Flows also should be adequate to inundate floodplains, which serve as critical rearing habitat for juvenile fish.


Does the Bay Delta Plan have anything to do with the CA WaterFix (i.e. Twin Tunnels)?

No. While both the BDP and CA WaterFix would affect the health of the San Francisco Bay Delta, the twin tunnels would convey water from the Sacramento River to the Delta pumps, where it is then sent south. The Bay Delta Plan will require more water to be left in our rivers for the benefit of fish and wildlife and the health of the Bay-Delta downstream.

Selected Resources

Map of Tuolumne River Watershed and selected areas of interest: