2005 Urban Water Management Plan - Sonoma County Water ...

Sonoma County Water Agency
2005 Urban Water Management Plan
Page 4-14
The Rohnert Park WSA has been challenged in court and the trial court found it to be invalid.
Rohnert Park has appealed the trial court decision and the matter is pending in the Court of Appeal.
However, the analysis of the groundwater supply presented in this plan does not rely on the WSA’s
conclusions. Rather, Brown and Caldwell and the Agency’s staff have reviewed, considered, and
summarized the available information for this plan, and have concluded groundwater levels in the
basin have had variable trends since 1990, but most wells have been relatively stable. A
comprehensive independent assessment of basin-wide groundwater conditions with respect to
potential overdraft is not required by the Urban Water Management Planning Act and is beyond the
scope of this Plan.
The use of recycled water in the Santa Rosa subbasin offsets demand for potential potable use by
agricultural operations. Recycled water use in the Santa Rosa subbasin has decreased somewhat over
the years due to increased emphasis on irrigation efficiency and crop conversion to vineyards which
have lower water requirements. The Santa Rosa Subregional Reclamation System provides recycled
water for agricultural users and will continue to meet the needs of the current agricultural
customers. 5
The Agency’s three groundwater supply wells are located in the Santa Rosa Plain north, east, and
southeast of Sebastopol. The Agency conducts a groundwater monitoring program of water levels
in seventeen dedicated monitoring wells in the vicinity of its three water supply wells to assess the
effects of these wells on local groundwater conditions. According to Agency records, continuous
operations of the Todd, Sebastopol, and Occidental Road water supply wells began in April 1999,
June 2001, and July 2003, respectively. Brown and Caldwell reviewed the available monitoring data
through early 2006 for the 17 wells for the purposes of this Plan. In general, the data document
normal seasonal fluctuations and initial declines in water levels in response to commencement of
pumping for monitoring wells in close proximity to the three water supply wells. A pump test of the
Agency’s three wells in 1979 found that “deep wells near the three emergency wells and some of the
shallow wells near the Occidental and Sebstopol wells were influenced” by pumping of the Agency
wells (SCWA, 1979).
5 Personal communication with Jennifer Burke, City of Santa Rosa, Oct. 27, 2006.
P:\27000\127280 - Sonoma County Water Agency\UWMPs\SonomaCWA\Tech Reviewed Chapters\SCWA Master 12-08-06.doc