Valley Water’s proposal to construct a huge new dam and reservoir would result in huge environmental costs and questionable benefits. The main benefit for Santa Clara County is a small amount of emergency water supply. Environmental benefits (outside of the County) were added to the project to obtain a Proposition 1 Water Storage Investment Program (WSIP) grant. The $500 million grant was supposed to cover half of the project when it was approved in 2017, but project cost estimates have ballooned to almost $3 billion ($5 billion with finance costs). Of course, environmental costs are not included, and they will be extensive. A draft environmental impact report (EIR) completed in 2021 identified 13 “significant and unavoidable” impacts. That EIR has been deemed insufficient, and a new draft EIR will be completed in mid-2025.
The Valley Water Board of Directors is set to discuss the following six topics during regular Board meetings starting in January 2024.
- Proposed operations and benefits: wet/dry year operations, fish habitat improvements, emergency water supply, water quality, etc.
- Environmental impacts and mitigation measures: update following May 2023 court order, proposed mitigations, etc.
- 2050 Water Supply Master Plan portfolio recommendation: comparison to other water storage projects, etc.
- Project costs: updated costs, mitigation costs, etc.
- Partnership approach: process and next steps, partnership operations, etc.
- Requirements unique to the project: water rights, public benefits, partnership agreements, etc.
(Sierra Club requested to add incursion into Henry Coe State Park.)
Topic #1 will be discussed at the February 13, 2024 Board meeting (starts at 1pm). Here are some things to look out for regarding claimed benefits.
- The proposed additional flows and the restored habitat below the new dam will not guarantee development of an independent Steelhead population. The National Marine Fisheries Service has questioned how the objectives for water supply reliability/operational flexibility and for increasing habitat for steelhead via improved flow and water temperature conditions will be managed during drought periods. Operational parameters for the 35,000 acre-foot habitat storage reserve need to be presented to the Board.
- More information is needed to quantify the benefits of providing water to San Joaquin River wildlife refuges in below-normal water years (one of five water year types). The information provided to the Board should include how much would have been supplied between 2012 and 2022, to get a feeling for the magnitude.
- It is unlikely that water quality issues caused by poor-quality imported water will be eliminated in Pacheco Reservoir. These water quality issues are currently being addressed by blending with other water sources and adjusting water treatment – much less costly solutions. Due to costs for pumping and evaporation loss, Pacheco should only be used when the groundwater basins are full, so will often be at low levels and will be warm, conditions conducive to algae blooms and other water quality issues.
- Valley Water should stop presenting flood protection as a project benefit. It is misleading to the public to group this incidental benefit with the documented benefits of the project.
- The Board should request an independent review of this benefit analysis because many factors are not fully addressed. This may be true for future topics as well. We expect Valley Water will continue to selectively analyze and present information about the Pacheco Reservoir project to avoid discussion of the deeper issues.
Meeting agendas are posted here: https://scvwd.legistar.com/Calendar.aspx.
If you have questions or would like to help stop the Pacheco Dam Project, contact Katja Irvin, grg.conservation@lomaprieta.sierraclub.org.