San Vicente Dam-raising project begins
Posted by George J Janczyn on July 9, 2009
It’s been years in planning, but groundbreaking on the San Diego County Water Authority’s (SDCWA) project to increase storage capacity by raising San Vicente Dam by over 100 feet has begun.
The general tone of local media reporting has been of excitement and relief. KPBS quotes Maureen Stapleton (SDCWA General Manager) gushing “That’s enough water for 300,00 homes for a full year.” The impression seems to be that we’ll soon have plenty of water to handle more homes.
But according to the public reports I’ve read, the extra water is supposed be stored for use in case of an emergency with our imported water supply. The problem I see is whether that emergency water will eventually become “normal” water to supply our growth and increasing demands.
Interestingly, an Oct 2007 EPA memo commenting on San Diego’s Draft Environmental Impact Report alluded to this ambiguity, asking why “water storage reliability” and not “water supply reliability” was given as the reason for the project (they point out that demand could be satisfied through means such as conservation and water-transfers rather than dam expansion). In other words, they thought we want the extra capacity to meet increasing demand, not just provide for emergency storage.
However, I cannot locate the final environmental impact report to see how this question was answered, even though an April 2008 notice posted in the Federal Register says the final report is available online at SDCWA’s website. Perhaps I didn’t dig enough.
In any case, enthusiasm for this water project should not dampen our efforts to reduce demand.
Additional information:
GrokSurf's San Diego 
David Zetland said
Good post and good point. SD LOVES growth and growth puts reliability @ risk. More interesting — where’s the extra 300TAF coming from?
lostlandscape said
I guess I agree with the other responder. Life in California has made me into a reservoir is half-empty kind of person, and increasing the capacity will only turn it into a two-thirds empty reservoir. Raise the dam and the water will come? There seems to be a logical lapse in that figuring…
GrokSurf said
How will they fill the extra capacity?
According to SDCWA, it will take 2-5 years of wet seasons to accumulate enough water to refill the dam after construction is complete. Aside from local runoff, water in the reservoir is typically imported through a pipeline already, so extra purchases could be made.
Another source of water: the city proposes to perform highly advanced treatment on reclaimed water and then blend it with the water in the reservoir (which is not yet treated). This is known as IPR Indirect Potable Reuse. The blended water would then go to the Alvarado plant near Lake Murray for final treatment. The IPR demonstration project in progress by the city will design and test an advanced water treatment plant that would produce 1 million gallons per day. That’ would be a relatively small but reliable amount.