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Do Coastal Streams Go Dry Naturally?

At the presentation to the Sonoma County Board of Supervisors on Frost Protection, County staffer Peter Rumple said that “streams go dry naturally”.  This was reiterated by Peter Opatz, vineyard manager.  Peter Rumple also indicated to Board of Supervisors that the Eyler Report was the latest and best of studies done on frost protection.

In response to the idea that “streams go dry naturally”  —
“Empirical data collected in Maacama and Franz Creeks indicate that stream flow recedes quickly when water is needed for frost or heat protection at magnitudes approximately equal to the demand hydrographs presented here.” (Supra Deitch, 2006 cited in 2007).  In addition, “[t]he model indicates that existing diversions have little capacity to influence peak or base flows during the rainy winter season, but may reduce stream flow during spring by 20% in one- third of all the study streams; and have potential to accelerate summer intermittence in 80% of  the streams included in this study.”
“”Based upon conservative estimates of current demand, the surface water balance study conducted in 2006-2007 states that,  “ [i]n the streams studied here, sufficient flows do not exist to meet human demands during spring and summer, but winter discharge may be sufficient to meet human needs later in the year (Surface water balance to evaluate the hydrological impacts of small in stream diversions and application to the Russian River basin, California, USA 2007 by Merelender, Deitch, and Kondolf;emphasis added).  The authors go on to explain that , “[t]he classic water balance as commonly applied is not useful for exploring impacts of human water use relative to flow regime because the time scale over which it typically operates is not congruent with stream flow.”
Surface water balance to evaluate the hydrological impacts of small in stream diversions and application to the Russian River basin, California, USA 2007
“HYDROLOGIC IMPACTS OF SMALL-SCALE INSTREAM DIVERSIONS FOR FROST AND HEAT PROTECTION IN THE CALIFORNIA WINE COUNTY”
Submitted by Larry