A recent editorial, "Water 101," suggested that Sonoma County water providers were doing something nefarious by using ground water as a substitute for Russian River water. The editorial referred to a news story which reported the sources of water used by local cities and water districts since the beginning of state-imposed mandatory 15 percent cutback in Russian River water. The article noted that while cities had conserved, they had also reduced their use of Russian River water by relying on ground water instead.


There were several problems with the editorial and its assumptions.

First, it's important to understand that ground water has been, and will continue to be, an important source of water to local cities and the Water Agency. In fact, the California Water Management Plan 2005 devotes a chapter to the "conjunctive use" of ground water when surface water (like the Russian River) is restricted by either climatic or regulatory conditions.

By using river water and ground water conjunctively, ground water sources are recharged when surface water is available. Underground aquifers are to a large degree insulated from annual fluctuations in rainfall that impact surface reservoirs, making them an important water source during dry years.

Second, the editorial stated that "residential wells in the same aquifers may go dry" if cities used ground water. The Water Agency and its contractors are funding research by the United States Geological Survey that will provide scientific basis for further management of ground water and surface water. It is important to the contractors that ground water management be based on science.

Third, your editorial failed to mention that many cities and water districts in both Marin and Sonoma counties use recycled water for irrigation. These efforts have preserved water stored, not only in Lake Mendocino, but in Lake Sonoma which is currently at 213,100-acre feet -- or 87 percent of capacity.

It would be imprudent for water contractors to rely on one single method of reducing our reliance on Russian River water, which is why we've taken a collaborative, integrated approach that includes conservation, recycled water and local sources.

Chris DeGabriele is the general manager of the North Marin Water District. Krishna Kumar is the general manager of the Valley of the Moon Water District. Both are members of the Technical Advisory Committee to the Sonoma County Water Agency's Water Advisory Committee.