Sonoma County Urban Water Management Plans

By Brenda Adelman
The hot topic among Sonoma County water wonks is the Urban Water Management Plan (UWMP). This is the water use plan required of all California utilities that provide water to over 3000 people or utilize over 3000 acre feet of water each year (one acre foot is about 325,000 gallons). It’s like the General Plan for water availability and projected need within the districts of each water utility.

UWMP documents are officially referred to as the 2010 Plan, although the submission deadline has been extended to July 1, 2011. The 2010 Plan projects water use and availability out to 2035, but new Plans and projections will be written every five years. The next one is due at the end of 2015.

It’s important to realize that Plans include projections which are based on past events but often utilize intuition, along with scientific guesstimates. Computers are used to make the graphs and charts, but human assumptions form the basis for the analysis and as such, are subject to human error. Yet important development decisions about the availability of water are based on those assumptions.

2005 Plan legally challenged by environmentalists……
The 2005 Plan, authored by the Sonoma County Water Agency (SCWA), was legally challenged by 15 environmental groups for making contractual commitments to water deliveries for which rights had not yet been obtained. This was referred to as “paper water”. The lower court ruled that the Agency had inadequately defined the source of supply, and Judge Gary Nadler deemed the 2005 Plan inadequate.

This 2005 Plan was predicated on the assumption that the State would increase their water rights from 75,000 acre feet per year (afy) to 101,000 afy. The State told the Agency that new permits would NOT be granted until Biological Opinion requirements, including permanent changes to river flow (Decision 1610 revision) were fully implemented, and that was not due to be complete until about 2018.

The Superior Court ruling was appealed by SCWA and was subsequently heard by the State Appellate Court. Appellate judges were of a different mind than the lower court and they reversed the decision. The groups tried to get the matter heard by the State Supreme Court, but the Court declined to hear arguments against the ruling. The original suit had challenged the veracity of the information contained in the UWMP, but the Appellate Court ruled that SCWA had the expertise to determine whether the supply was adequate and that the legal challenge providing contrary information by other experts, was no more valid than that of the Agency’s. Obviously, many of us felt this was not a good ruling for the river environment, but events move on.

Current Plans broken into pieces….
In the current round, tasks have been split apart, with contractors composing their own Plans for projected water demand and SCWA focusing on water availability. The Agency’s water supply Plan has numerous components, including the Potter Valley Project, Lake Mendocino and Coyote Dam, Lake Sonoma and Warm Springs Dam, water supply, ground water, recycled water, conservation, Decision 1610, etc.


During dry periods, when supplies are greatly limited, contractors are informed that they cannot rely on the river as a source for water and must utilize their own local sources. These sources include local groundwater wells, accelerated conservation, use of wastewater for landscape irrigation, etc. Each entity is responsible for developing their own Plan. (The eight major contractors are Santa Rosa, Sonoma, Valley of the Moon, Petaluma, Cotati, Rohnert Park, North Marin Water District, and Windsor. Marin Municipal has an agreement to take off-peak water supplies.)

We will be examining Santa Rosa’s 380-page Plan in the near future. Outside experts were hired to analyze the needs of the system in great detail. Their UWMP can be found at: www.srcity.org/2010UWMP The Water Agency’s Plan can be found at: www.scwa.ca.gov/water-supply/ Plans for the other contractors should be available on their individual websites. We cannot track them all.

SCWA lowers expectations for water diversions….and hearings….
Each of these plans makes certain assumptions and contains certain goals. The Water Agency’s current Plan assumes that by 2035 (the life of the Plan) their projected water need will be just below 80,000 afy. The current water rights supply of 75,000 afy won’t be exceeded until 2027. (In the 2005 Plan, SCWA anticipated needing 101,000 afy by 2020.)


On Tuesday, May 24th, the Hearing on the Agency’s Plan took place before the Directors of the Water Agency (Board of Supervisors), and everyone (including water activists) praised the Agency for pulling far back on water supply projections. Santa Rosa’s Hearing before their City Council for their Plan will be June 14, 2011 at or after 5 pm in City Council Chambers at 100 Santa Rosa Ave. Other contractors will have their own plans and hearings. Check their websites for specific information.

Lower river loses out….again…..
It is not possible to go into more detail in this article, but there is one issue in the Agency’s Plan that we would like to emphasize. Many people in the lower river have questioned whether we are getting the short end of the supply through the implementation of “low flow”. We discovered a statement in the Water Agency’s Plan, which seems to indicate that this is the case. But first, we can say that the really low flows will generally occur just in water-short summers when the reservoirs are not full and a hot summer causes supplies to be considerably drawn. In that case, there will probably be shortages for everyone. In cool, wet years, water levels will probably be normal for most of the summer.

The Agency’s Plan states on page 2-6:
“…for normal water supply conditions, because minimum instream flow requirements below the confluence of Dry Creek and the Russian River are (and under the proposed reduced Biological Opinion flows will continue to be) lower than the instream flow requirements in the Russian River above Dry Creek, the Water Agency is not required to release water from Warm Springs Dam to meet instream flow requirements in the Russian River below Dry Creek. To this extent, water stored in Lake Mendocino provides an incidental water supply benefit to the Water Agency’s transmission system customers.”

This statement says it all! The Water Agency sees “low flow” as being advantageous to their water delivery role. RRWPC will be watching closely.


Brenda Adelman is chair of Russian River Watershed Protection Committee. She can be reached with questions at rrwpc@comcast.net