NEVADA CITY, Calif. March 15, 2017 – Over the past few years, NID has presented various rationales for embarking on the Centennial Dam project. However, by their own analysis, they have enough water to more than meet projected needs up to 2040 and have only incremental needs beyond that. In February, I reviewed some of the many alternatives to Nevada Irrigation District’s (NID) Centennial Dam project presented at the Alternatives to the Centennial Dam Workshop at the SYRCL Wild and Scenic Film Festival. I ended that column with the question, “What is the purpose of the project if there is a better way forward?”
In the February 10, 2017 United States Federal Register, the US Army Corps of Engineers published NID’s stated purposes for the dam: “…to provide drought and climate change mitigation, meet projected future water supply needs, and improve water supply reliability for NID’s customers.”
Let’s look more closely at each of these laudable purposes to see if they are valid.
Drought mitigation: Fortunately, we have recent real-world drought experience to inform us. NID and its customers just survived the longest drought in California’s record with minimal conservation efforts and NID was able to easily provide water deliveries. Therefore, with aggressive implementation of well-known efficiency and passive conservation alternatives, NID is poised to navigate even further drought events.
Climate change mitigation: Again, we have recent experience to consider. Not only did we just experience the longest drought on record, but it is followed by a possible record-breaking water year. By definition, these are both rare events, but here they are, back to back, no speculation needed. We already know how some climate parameters are changing, but not how they will play out in combination over the next 100 or more years. These back-to-back rare events show that one thing for certain about California’s future climate and hydrology is uncertainty. Putting money down on uncertain outcomes is gambling and a billion dollars of tax and ratepayer money is a big bet.
Meet projected water supply needs: NID’s October 2016 application to the Nevada County Local Agency Formation Commission states that the historical average supply available to NID from all sources is approximately 386,500 acre feet per year (AF/yr). This amount can vary from year to year depending on climatic conditions that affect natural runoff.
The application also states the overall water needed for 2040 is projected to be 209,521 AF/yr.
In other words, with an average water supply of 386,500 AF/yr and a 2040 projected need of 209,521 AF/yr, NID has a surplus of 176,979 AF/yr. This is more than enough supply to meet projected demand with the existing system.
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More directly, the City of Lincoln General Plan calls for 20,000 new houses to be served with NID treated water. In its Raw Water Management Plan NID calculates that existing agricultural water will be converted to residential use to meet this need. This translates to an additional need of only 1700 AF/yr of new water. If new raw water customers in the Lincoln area along the proposed Raw Water Supply Pipeline are included, the total demand for new water is 7,200 AF/yr. Either amount is only a fraction of the capacity of the proposed 110,000 AF Centennial project! I cannot find the need for 110,000 AF of new water, or anything close to it, stated in any NID water supply planning document.
Improve water supply reliability for NID’s customers: The NID Board of Directors and management know there are many expensive competing deferred maintenance issues throughout the system, all of which threaten water supply reliability for NID’s customers and contribute to water waste. Spending valuable staff time and financial resources on the risky and complex Centennial Dam is irresponsible when considered with the additional maintenance of planned acquisitions of PG&E facilities long past their useful life, such as the recently failed South Yuba Canal. NID must make increasing the existing system’s efficiency and reliability a top priority for maintenance and upgrades.
Centennial Dam is a risky, expensive, and inflexible project proposed when we face an uncertain water future. It is time to withdraw the project and meet it’s now clearly stated purposes with an alternative approach incorporating well-understood strategies of watershed improvements and improved system management. Investments in our watershed, infrastructure, and passive conservation efforts will create long lasting local jobs and guaranteed water supply outcomes and benefits for all of us.
Peter Van Zant is a former Nevada County Supervisor, Sierra conservationist and SYRCL volunteer. He lives in Nevada City.