By Jon Chown
The Soquel Creek Water District Board of Directors reviewed a proposal at their Oct. 6 meeting to sell up to 550 acre-feet of water a year to the City of Santa Cruz.
Protecting district customers and the groundwater basin would remain a priority, according to a staff report from General Manager Melanie Mow Schumacher, but the proposed agreement would give Santa Cruz another water source and generate revenue for the district at the same time. Final prices, the length of the agreement and other terms are still being considered.
“The main thing we see is that the project was always shown to raise groundwater levels quite a bit,” said Cameron Tana, principal engineer of Montgomery & Associates. “It would raise it well above what is needed to prevent seawater intrusion.”
Tana, a hydrologist, has worked closely with Soquel Creek Water since 2006 and helped develop the district’s groundwater sustainability plan. He presented the plan to the board. A key, he said, is that previous projections in the project was designed to pump 3,900 acre feet of water per year, but it’s using far less and current projections in the future have fallen to 3,200 acre feet year.
“The district doesn’t need 3,900 acre feet per year,” he said.
The proposal includes provisions allowing the district to suspend its transfer obligations during water shortages, equipment failures, contamination or other problems. A drought or concerns about groundwater sustainability could also trigger relief.
The presentation focused on the monitoring plan, how the transfers could affect groundwater levels and the basin’s progress toward long-term sustainability. It also covered how the transfers would fit into Santa Cruz’s broader water supply plans.
Seawater intrusion occurs when wells get so low that rising seawater enters them, spoiling the fresh water. Under the proposal, the agencies would use monitoring data to decide which pumping location to use and when to use it to prevent seawater from entering the groundwater supply.
Representatives would meet at least once a year, by March 1, to review the previous year’s groundwater data, identify trends and consider adjustments. Findings would be reported to both agencies’ governing boards.
The draft calls for evaluating how transfers affect the basin’s ability to meet state sustainability requirements by 2040. Beginning transfers no later than 2029 would provide at least a decade to study their effects and adjust operations.
Director Bruce Jaffe was particularly interested in what the situation would like look under different projections of how climate change might affect the water supply.
“I think that the choice of climate scenario is a very key part of this exercise,” he said.
Tana said climate change would not affect groundwater conditions nearly as much as it could change how much water the city needs.
“I would expect the city to request more water during a drought,” Jaffe said.
“Exactly! That is the problem,” responded director Carla Christensen.
“We’re only agreeing to 550,” said board president Tom LaHue.
The discussion followed an Aug. 18 board review of proposed terms. The district and city already cooperate on water supply and emergency planning. Santa Cruz provides source water for Pure Water Soquel, and the agencies have existing connections between their systems. Earlier pilot projects moved excess city surface water to the district.
Any revenue from the proposed sales would depend on the final agreement and the amount of water transferred.