Description of the Proposed Project

Overview of scwd2 Regional Seawater Desalination Project

The City of Santa Cruz and Soquel Creek Water District (scwd2) Regional Seawater Desalination Project (proposed project) would provide up to 2.5 million gallons per day (mgd) of potable drinking water. This water would help the District meet its water needs as it reduces its groundwater withdrawals of the overdrafted Soquel-Aptos area to prevent seawater intrusion. It would help the City meet the water needs of its service area during periods of water supply shortage as a result of drought and allow more water to be left in local streams and rivers to provide improved habitat for fish, and to plan for climate change by diversifying its water portfolio.

Overview of Project Components

The conceptual components of the proposed scwd2 Regional Seawater Desalination Project would include:

  • Seawater Intake: A seawater intake and conveyance system consisting of an intake structure, intake piping, pump station, and transfer piping;
  • Desalination Plant: A seawater desalination plant that would provide for pretreatment filtration, seawater reverse osmosis desalination and energy recovery, post-treatment processing and distribution, brine storage, residuals handling and disposal, and their associated support facilities.
  • Brine Disposal System: Brine storage, disposal, and conveyance system consisting of brine storage at the desalination plant, a new pipeline to the City’s Wastewater Treatment Facility (WWTF) outfall, and outfall improvements;
  • Conveyance System: Potable water distribution system improvements, consisting of a new connection to the City distribution system and a new intertie system between the City and District service areas, including new pipelines and pump station improvements; and,

Environmental design, construction, and operational features, consisting of various features of the components of the project and the project overall that would be implemented to avoid, reduce, or minimize potential environmental effects that might occur in the absence of such elements.

For a more detailed description of the project, see Section 4 of the Draft Environmental Impact Report.

Operational Strategy

The City and District propose to cooperatively operate the desalination plant to provide water to each agency during different times to meet the different objectives and needs of the two agencies.

Key issues include:

  • A conceptual priority system (see Draft EIR Appendix P) was agreed upon, which would allow the City to have priority to use the desalination plant during the summer months of any year.
  • It is expected that the City would typically use the desalination plant during years of below-normal water supply, as determined by stream flows and diversion limits in the City’s surface water sources.
  • During all other times, the desalination plant is expected to operate at a lesser capacity to provide the District water to offset groundwater that would otherwise be pumped from the aquifers, therefore allowing coastal groundwater levels to recover to target levels.

Each agency would finance the operational costs of the plant associated with their use.


Technical and Project Reports that are the Appendices to the Draft EIR

  • scwd2 Final Seawater Reverse Osmosis Desalination Pilot Test Program Report & Appendices (EIR Appendix D)
  • Proposed scwd2 Desalination Project Watershed Sanitary Survey (EIR Appendix E)
  • scwd2 Seawater Desalination Program Offshore Geophysical Study (EIR Appendix F)
  • City of Santa Cruz Water Department & Soquel Creek Water District scwd2 Desalination Program Open Ocean Intake Effects Study (EIR Appendix G)
  • scwd2 Seawater Desalination Intake Technical Feasibility Study (EIR Appendix H)
  • Dilution Analysis for Brine Disposal via Ocean Outfall (EIR Appendix J)
  • scwd2 Seawater Desalination Plant Phase 1 Preliminary Design – Volume 1 Report & Volume 2 – Drawings (EIR Appendix L)
  • Summary of scwd2 Energy and Greenhouse Gas Reduction Approach (EIR Appendix O)

To access the Draft EIR on-line, click here.

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