(c) SPAWNUSA.org, Todd Steiner

UC Berkeley Professor & SPAWN to Study Dam Releases to Determine Best Flow for Salmon

Read Marin Independent Journal report.

Olema, CA May 18, 2017 – SPAWN has been awarded $158,000 from the Wildlife Conservation Board to determine the most effective schedule and amount of water releases from Kent Lake that will benefit growth and survival of juvenile coho salmon and steelhead trout in Lagunitas Creek. The entire cost of the study is $223,000, with the $65,000 difference provided by SPAWN members and volunteers.

The study will concentrate on understanding the best conditions for salmon during the winter and spring and will be conducted by SPAWN’s Watershed Conservation Director, Preston Brown with input and oversight from University of California, Berkeley adjunct professor Ted Grantham, Ph.D., who has conducted similar studies on dams in California, and with the Department of Environmental Science, Policy and Management.

Current water releases from Peters Dam were set in 1995 under Water Board Order: WR 95-17, making them 22 years old. A lot has changed since then and much of the new knowledge of habitat needs, limiting factors analysis, and instream flow requirements for salmonids were not accounted for in developing the current flow regime that is now almost a quarter century old.

“This study is intended to provide recommendations to water managers who can maximize the benefit of stream releases by fine tuning the amounts, magnitude, frequency, and seasonality needed to best activate floodplains downstream that allow juvenile salmon to grow and flourish,” said SPAWN’s Preston Brown. “We know a lot more now than we did almost a quarter century ago when water releases were mandated, and we will incorporate this vastly increased knowledge with new modeling to determine the best floodplain flows for salmon.”

This project aims to understand if modified water releases to optimize stream flows and encourage overbank flows can benefit endangered salmon survival by providing additional habitat to feed, grow, and find refuge during important life stages.

“We believe modified water releases may improve important ecological processes that benefit salmon survival, such as food-web production, vegetation succession, and streamwood recruitment,” said Brown. “We are eager to provide that information to water managers, regulators, biological practitioners, and the public in order to make the best decisions to protect our stream ecosystems.”

The floodplain activation flow will identify the magnitude, frequency, duration, and seasonality of stream discharges needed for a flood event to facilitate critical ecological benefits for salmonids as needed for rearing and other ecological processes, which are not accounted for in the current release regime.

“I am delighted to lend my expertise in order to provide the best available science to help manage this critically important population of Central California coast coho salmon,” said Ted Grantham of UC Berkeley.

Specifically, SPAWN and UC Berkeley’s Grantham will determine the floodplain activation flow through topographic mapping, 2D hydraulic modeling, real-time hydrologic measurements, salmonid habitat suitability determination, and comparisons to the floodplain activation flow to the historic flow regime.

“SPAWN is committed to doing everything we can to prevent the extinction of Marin’s critically endangered coho salmon, said Todd Steiner, biologist and executive director of Turtle Island Restoration Network (SPAWN is a program of Turtle Island), and this research is an important piece of the puzzle. Once we have the data, we will work with water managers and the public to develop a plan to help salmon survive and thrive in Marin.”

About SPAWN:

TURTLE ISLAND RESTORATION NETWORK’S SALMON PROTECTION AND WATERSHED NETWORK (SPAWN) program works to protect endangered coho salmon and steelhead trout, and the environment on which we all depend. The protection of these keystone species leads to the protection of all the wildlife of our community, and indeed the protection of our land and us.

SPAWN uses a multi-faceted approach, including grassroots action, habitat restoration, policy development, environment education, and collaboration with other organizations, media campaigns, and strategic legal action.

Visit SeaTurtles.org/Salmon to learn more.