Recent near-record storms make the case for Sites Reservoir

A powerful series of storms slammed Northern California in the first days of the new year, producing record rainfall that saturated the ground and made it more vulnerable to flooding and excessive runoff. The rainfall is welcome after the unprecedented drought of the last few years. As we’ve seen in the news the past few weeks, we’ve got to do better in more efficiently using these storm flows when they come to save for the inevitable drought periods that define the Mediterranean climate we live in. We’re working hard to do that in making Sites Reservoir a reality.

Sites is specifically designed to divert and store water generated by storm events like we’ve seen these past three weeks to increase water flexibility, reliability, and resiliency in drier years. If Sites were operational this year, we would have been able to divert and store 120,000 acre-feet from January 3 to January 15. That’s equal to less than 4% of Delta outflow, leaving plenty of water in the Sacramento River and Delta to serve important ecosystem functions. Additionally, long-range forecasts project Sites would continue to divert stormwater through at least February 15, collecting a total of 382,000 acre-feet of water over this period. All of this water would be diverted after all other water rights and regulatory requirements are met and with the Sites Project’s protective diversion criteria.

Some of the recent news articles have identified that new dams in California aren’t likely to be built or that all of the good locations for dams are gone. We challenge that position. 19^th century dams were on river, assuming snowpack, and in conflict with the environment.  This approach is in conflict with the current value system in California and in the face of climate change. Sites is a 21^st century surface water storage system. It’s a project designed with environmental values side by side with water supply needs and designed to serve these co-equal goals for our changing climate. Sites is off-stream and doesn’t dam a major river or natural migration pathways for fish. Sites is a stormwater capture project, diverting only in high flow/flood flow conditions like we’re seeing now and doesn’t rely on snowpack. Sites diverts through state-of-the-art fish screens and only after highly protective fish criteria have been met. I’m not saying Sites is the silver bullet solution to California’s water challenges, but it’s an important component and we should not dismiss the fact that we can use human ingenuity to develop new, environmentally conscious infrastructure to solve our challenges today and for generations to come.

We’ve also heard a lot in recent news articles on groundwater recharge and we agree. Continuing our way of life and prosperity as a state into the future relies on a portfolio of water management efforts – conservation, groundwater management, desalination, conveyance improvements, surface and groundwater storage, and other measures as reflected in the Governor’s August 2022 Water Supply Strategy. An “all of the above” strategy is prudent because just like your retirement portfolio, diversity is stability. Each asset will perform better or worse in different scenarios and at different times – and water assets are no different.

Periods of heavy rainfall, like the atmospheric rivers these past few weeks, are ideal opportunities to divert and capture water that accumulates quickly but is lost to flooding and rapid runoff. Atmospheric rivers carry, on average, 400 billion gallons of water—as much water a day as the Mississippi River—leading to storms that can last several days. When there is excess storm and flood water, we must be prepared with infrastructure to capture some of this water for future use while leaving some in our rivers for the important purpose it serves to our natural environment. Sites Reservoir is designed with this in mind.

If recent droughts have taught us anything, it’s that we shouldn’t pass up any opportunity to store water for the next, inevitable, drier day. We won’t have to with Sites Reservoir.

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