Last Friday, in one of the clearest news stories ever, the Contra Costa Times reported why a huge Delta Conveyance tunnel does not make sense in the article “Delta’s winter surge undercuts rationale for big diversion of Sierra water around it.” Proponents for a large scale tunnel or cannel argue the mega-structure’s capacity is needed to capture and divert rare high river flows in due to increased snowmelt. The report found when the big flow came through this spring, “Delta water managers’ pumps diverted no more than about half what it would take to fill the proposed 15,000-cubic-foot-per-second aqueduct under study. Most days, the pumping rate was far less.” 

The report further states, “A smaller version — perhaps one-fifth the size contemplated — would be cheaper, deliver nearly as much water and could not be misused in ways that would harm drinking water quality and fisheries, they (Contra Costa Water District and others) contend.”

These problems are in addition to the costs for the huge tunnel which have skyrocketed to a current estimate of $16 to $20 billion (not including interest on the bonds that will double the real costs).