Scientific Study Contradicts Basis for State Water Board’s River Flow Mandates

By Aubrey Bettencourt | Fox & Hounds

A new environmental study, published in in the prestigious North American Journal of Fisheries Management, reveals that Governor Jerry Brown’s State Water Resources Control Board (SWRCB) imposed so-called pulse-flow release requirements on water rights holders affecting several California rivers, operating from unproven beliefs the study now shows were without sufficient scientific basis.

Pulse flows, as ordered by the SWRCB, are short-term increases in outflow releases from California’s numerous dams. These flows have cut water deliveries to millions of Californians, forced some to drink foul-smelling water and required hundreds of thousands of acres of food-producing farmland to remain empty and unplanted.

While the SWRCB insists these pulse flows ease the passage of migrating fish, numerous parties, ranging from private citizens to the California Department of Water Resources, have labeled such releases as “ineffective,” “misguided” and “excessive.”

They are right in their criticism as the new study finds the SWRCB’s pulse flow requirements do not help migrating fish and in fact actually harm fish.

Why does the SWRCB rely on [Alt] Science — a slang term for what many feel is junk science — and false impressions of pulse flows to shape public policy?

The paper, “Environmental Factors Associated with the Upstream Migration of Fall-Run Chinook Salmon in a Regulated River,” by Matthew L. Peterson, Andrea N. Fuller and Doug Dempo, appeared in December. The peer-reviewed research was conducted on the Stanislaus River over 12 years, from 2003 to 2014.

Ironically, the SWRCB imposed its increased flow requirements on various irrigation and water districts only after it observed voluntary pulse flow tests by Oakdale Irrigation District, beginning in 1992. The District sought to learn whether pulse flow releases would benefit migrating salmon and steelhead. In 2003, Oakdale’s ratepayers provided funding to help the researchers begin their study, and District-funded trials and fish counts have continued to the present date.

To Oakdale’s surprise and dismay, the SWRCB quickly made pulse flow requirements mandatory across many state rivers and many other water districts before clear evidence of any beneficial effects on fish could be established. Millions of acre-feet of water have been spilled for such releases over the past decade.

Now, the evidence is in. The study shows that pulse flows are a mixed bag. Over 12-years, researchers observed and counted 38,206 Chinook salmon in the Stanislaus River.

“Managed pulse flows resulted in immediate increases in daily passages, but the response was brief and represented a small portion of the total run,” the study continues.

Migration increases stopped whenever river flows increased beyond 700 cubic feet per second. Most SWRCB-mandated pulse flow orders far exceed that rate of flow and actually have a negative effect on fish migration, the study shows.

But don’t confuse the SWRCB with facts.

Now SWRCB is moving rapidly to order even higher flows on all tributary streams of the San Joaquin River, including the Stanislaus River studied by researchers.

“Current management requirements in the Stanislaus River exceed this [700 CFS rate-of-flow] level and adjustment should be considered based on the findings of this study, particularly given the need to balance beneficial uses of a limited water supply,” says the scientific article.

Academics agree that real science — carefully designed to draw on real-world observations and using thorough experiments to determine the benefits of various actions to endangered species — is far preferable to the [Alt] Science assumptions, guesses, and unfounded intentions of the SWRCB or those who encourage the state to increase pulse flows from dams.

California already requires its environmental agencies and their boards and commissions to reflect real science in their regulations and public policy decisions, not guesses.

The state’s water board appears to have disregarded its lawful responsibilities when it imposed pulse-flow requirements and proposed additional unimpaired flows on water managers and users. The recent study suggests its actions may have caused harm to the state’s already endangered Chinook salmon and steelhead species.

Besides the study’s authors, sister agency the California Department of Water Resources testified against the SWRCB’s past and proposed pulse flow actions as “without evidence, incomplete scientific information, ill-suited for real-time operations, and unverified assumptions.” Still the SWRCB is set to close of public comments whether to demand increased pulse flows again March 17, 2017.

But hey, don’t confuse the SWRCB with facts or real science.