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Proposed Policy for Maintaining Instream Flows in Northern California Coastal Streams

The State Water Resources Control Board will hold a public hearing to Receive Comments and to Consider Adopting a proposed Policy for Maintaining Instream Flows in Northern California Coastal Streams

Tuesday, April 27, 2010
10:00 a.m.
Coastal Hearing Room
Joe Serna, Jr./Cal-EPA Building
1001 I Street, Second Floor
Sacramento, CA 95814

Water Code section 1259.4, which was added by Assembly Bill 2121 (Stats. 2004, ch. 943), requires the State Water Resources Control Board (State Water Board) to adopt principles and guidelines for maintaining instream flows in northern California coastal streams as part of state policy for water quality control, for the purposes of water right administration. The proposed Policy for Maintaining Instream Flows in Northern California Coastal Streams (proposed policy) was developed to comply with Water Code section 1259.4.

The purpose of the proposed policy is to preserve the instream flows needed to protect fishery resources, while minimizing the water supply impacts of the proposed policy on other beneficial uses, including agricultural, municipal, domestic, and industrial uses. The proposed policy will apply to applications to appropriate water, small domestic use and livestock stockpond registrations, and water right petitions. The geographic scope of the policy encompasses coastal streams from the Mattole River to San Francisco and coastal streams entering northern San Pablo Bay, and extends to five counties — Marin, Sonoma, and portions of Napa, Mendocino, and Humboldt Counties. Streams in the policy area provide habitat for steelhead trout, coho salmon, and Chinook salmon, which have been listed as threatened or endangered species under the federal Endangered Species Act and the California Endangered Species Act.

The proposed policy contains guidelines for evaluating whether a proposed water diversion, in combination with existing diversions in a watershed, may affect instream flows needed for the protection of fishery resources. It prescribes protective criteria limiting the season of diversion, establishing minimum bypass flows, and limiting the maximum cumulative rate of diversion from a watershed. As an alternative to the criteria specified in the proposed policy, the policy allows site-specific studies to be conducted to evaluate whether different protective criteria could be applied. The proposed policy also limits construction of new onstream dams and contains measures to ensure that approval of onstream dams does not adversely affect instream flows needed for fishery resources. The proposed policy provides for a watershed-based approach to evaluate the effects of multiple diversions on instream flows within a watershed as an alternative to evaluating water diversion projects on an individual basis. Enforcement requirements contained in the proposed policy include a framework for compliance assurance, prioritization of enforcement cases, and descriptions of enforcement actions.