Petition by Sonoma County Water Agency Requesting Approval of a Temporary Urgency Change in Permits

Petition by Sonoma County Water Agency Requesting Approval of a Temporary Urgency Change in Permits

Sonoma County Water Agency (SCWA) is filing a temporary urgency change petition with the State Water Resources Control Board (SWRCB) that asks the SWRCB to make the following changes in the instream flow requirements for the Russian River mainstem that are specified in SWRCB Decision (D-1610) and SCWA's water right permits: (a) for April 6 through June 30, 2009 the D-1610 instream flow requirements for Dry conditions will apply in the Russian River (from its confluence with the East fork of the Russian River to its confluences with Dry Creek) and 85 cfs in the lower Russian River (downstream of it confluence with Dry Creek)); (b) if, during the period from April 6 through June 30, 2009, total inflow into Lake Mendocino is greater than 25,000 acre-feet, then, for July 1 through October 2, 2009, the D-1610 requirement for Dry conditions will apply in the Russian River. SCWA states that, without these requested changes in the minimum flows, Lake Mendocino is project to be empty by September 2009m which would in turn cause severe impacts on the fishery and recreation resources that depend on the upper Russian River, and on water users that rely on the upper Russian River for their water supplies. If Lake Mendocino is empty, the municipal, domestic and agricultural water users who depend on direct diversions from the river or from wells near the river could be without water, presenting an imminent danger to public health, safety, and fire protection activities. During the fall of 2002, low water levels in Lake Mendocino caused serious risks to Mendocino County water supplies and to fish species listed under the federal Endangered Species Act (ESA): coho salmon (endangered), steelhead (threatened), and Chinook salmon (threatened). Additionally, recreation at Lake Mendocino was seriously impaired. Because of these problems, the Mendocino County Board of Supervisors declared a state of emergency in 2002. Similar problems were avoided during 2004 and 2007, other similarly dry years; because the SWRCB temporarily amended the D1610 minimum flow requirements through its WR Order 2004-0035-EXEC and WR Order 2007-0022. Since water year 2009 presents even more serious risks, SCWA is requesting that the SWRCB temporarily change the instream flow requirements in SCWA's water right permits to reduce the amount of water that SCWA is obligated to release from Lake Mendocino increases as storage decreases. The proposed reduction is required minimum instream flows would allow for cooler and more stable flows in the upper Russian River during the fall. Because temperatures in the late summer and early fall period are already higher than optimal for salmonoids, an increase of water temperatures due to lower water storage in Lake Mendocino could negatively affect juvenile steelhead rearing in the main stem Russian River. Since adult Chinook salmon will be migrating upstream to spawn during the fall period, it would be more favorable for Chinook to reduce flows during the summer to conserve storage in Lake Mendocino than to wait until October to begin ramping down when adult Chinook are already in the river. The SCWA controls and coordinates water supply releases from the Coyote Valley Damn and Warm Springs Damn projects in accordance with the requirements of Decision 1610, adopted by the SWRCB in 1986. Decision 1610 specifies the minimum flow requirements for Dry Creek and Russian River (see Figure 1). These requirements vary based on defined hydrologic year conditions. The requested reduction in Russian River instream flow requirements would be in effect through October 2, 2009. Under Normal hydrologic conditions, minimum flows during this time period could be as high as 185 cfs in the upper Russian River, 125 in the lower Russian River, and 80 cfs in Dry Creek. Under the proposed change, minimum flows could be as low as 25 cfs in the upper Russian river and 35 cfs in the lower Russian River. The minimum flow in Dry Creek is proposed to remain at 80 cfs. The proposed change in Russian River instream flow requirements are the same as those that already occur during Dry and Critical hydrologic conditions under SWRCB Decision 1610.

Mendocino, Sonoma