Retired Water Manager Calls for Regional Swap
In an editorial in the Santa Cruz Sentinel on April 25, 2010, retired Santa Cruz Water Production Superintendent, James Bentley, wrote, “The City Council has been swayed into accepting a costly and environmentally unfriendly water solution when another viable and sustainable option exists which could minimize or eliminate the need for desalination.” The option Bentley refers to is the water swap with Soquel Creek District -- sending wet season water to Soquel in exchange for well water during drought.
Bentley participated in discussions of water supply options in the late 90’s that included this option detailed in the Alternative Water Supply Study (2000). That option was dismissed because the City was concerned that it would lose water diversion rights if it re-opened rights negotiations with the state. That concern is no longer an issue because the City has opened negotiations with National Marine Fisheries Service regarding fish habitat. Bentley calls for putting the water swap option back on the table. The following article includes a description of that option.
Making Use of Winter Flows
John Ricker, County Water Resources Division Director, is exploring two options that would make use of winter runoff to recharge aquifers and improve fish habitat in our streams. The first option is to divert water using existing City of Santa Cruz diversion and treatment facilities during high-flow periods in the San Lorenzo River to restore aquifer levels in Scotts Valley. That water would be used to reduce winter groundwater pumping in Scotts Valley and/or be infiltrated into abandoned quarries to recharge the Santa Margarita Aquifer, where the water is 200 feet below its historic level due to pumping by Scotts Valley. This recharge and in-lieu recharge would increase both groundwater storage and dry season base flow in the San Lorenzo River, improving fish habitat. Another approach in the same area would restore stormwater infiltration in developed, impervious areas of Scotts Valley to increase groundwater storage and reduce storm runoff.
The second option Ricker is exploring is for City of Santa Cruz to send treated surface water during high-flow periods to Soquel Creek Water District. During those periods the District could reduce its pumping of groundwater, thereby allowing the aquifer to recover. This option was considered in a study commissioned by the Santa Cruz Water Department published in 2000.1 That study included the possibility that in return for getting water from Santa Cruz during wet periods, Soquel Creek District would deliver well water to Santa Cruz during droughts. According to the study, “Limited use of the wells by the Soquel Creek Water District during winter periods – when supply could be augmented by the City – should reduce the stress on the aquifer and enhance natural recharge.”
Both options would require revision of the City’s water rights to divert water from the San Lorenzo River and possibly the North Coast Streams. Some of those rights date back to pre-1914, when the State didn’t require bypass flows to preserve fish habitat. Consequently, the City has a right to take unlimited water from the North Coast Streams. Its water rights to the San Lorenzo River at the Ocean St. Extension diversion have no minimum bypass flow requirements. Water rights for the Felton Diversion for diversion of high winter flows include minimum bypass requirements, but these may not be adequate, given the increased concern and greater understanding of fish flow requirements. In 2000, the Water Department did not pursue the option of a regional water swap with Soquel Creek District because of a concern that re-opening water rights would allow the State to require significant reductions in summer water diversions. According to Bill Kocher, Santa Cruz Water Department Director, this concern is no longer an issue, since the City has since entered into a process of developing a Habitat Conservation Plan that will modify its water rights to surface streams.
Despite the fact that the Habitat concerns are no longer at issue, Santa Cruz Water Department has not responded favorably to our request that this option be re-considered. According to Bill Kocher there option is not worth pursuing because the Purisima Aquifer is in overdraft and therefore Soquel Creek District would not be able to export water to Santa Cruz during a drought. Our response is that the agreement between Soquel District and Santa Cruz should include a provision that Soquel would match Santa Cruz’s curtailment during drought years. Then there would certainly be water available to deliver to Santa Cruz. For example, in a drought where Santa Cruz and Soquel are curtailing water use by 20%, Soquel could send 20% of its normal season well water to Santa Cruz. That’s the minimum Santa Cruz would receive. Once the aquifer reaches a level safe from salt-water intrusion, the potential to export water to Santa Cruz could be significantly higher.