Alternative Water Supply Study

City of Santa Cruz, 

Alternative Water Supply Study

Service Type: 
Project Highlights: 
  • Feasibility analysis to identify the most viable new supply alternatives.
  • Design criteria and costs are being developed for a 30-mgd regional desalination plant.
  • Desalination facility with additional water capacity to serve a neighboring district.
ocean waves

In November 2000, Carollo completed the Santa Cruz Alternative Water Supply Evaluation. It provides the basis for future Santa Cruz water supply projects, which will include additional sources to help offset shortfalls during drought, and to meet projected future demands. The foundation for the work included a detailed operational model of Santa Cruz’s complex raw water supply system. The team estimated the working yield of the system, and projected supply deficits for a 50-year planning horizon. Carollo then linked the model output to a conceptual engineering analysis of 10 new water supply alternatives, including ground and surface water, and seawater desalination. The team evaluated each alternative with respect to available supply, cost, and implementation. The screening evaluation highlighted the five “most viable” alternatives, which are currently being ranked and prioritized by Santa Cruz. The project also involved coordination of Santa Cruz’s public outreach program. In follow-up to the original work, Carollo is currently assisting Santa Cruz with an evaluation of a 30-mgd regional desalination facility, with capability to serve both Santa Cruz and the neighboring Soquel Creek Water District.

Carollo is assessing the economics and feasibility of siting and permitting a regional seawater desalination facility. The goals of this feasibility study include:

  • Assessing regional water demand needs (including an assessment demand off-set by planned reuse applications).
  • Development of a facility-siting rationale.
  • Identification of possible desalination facility locations, including alternative intake and outfall systems (open ocean or beach well intakes).
  • Identification of finished water distribution system impacts and upgrades.
  • Evaluation of brine disposal options.
  • Assessing environmental issues associated with plant siting and brine disposal (facilitate meetings with City of Santa Cruz, Soquel
  • Creek Water District, the California Coastal Commission, and Monterey Bay National Marine Sanctuary officials).
  • Development planning-level design criteria for the facility and process.
  • Estimation of costs.

Carollo is evaluating site selections and economics for a 30-mgd regional seawater desalting plant.