By Jed Smith

Three years ago, drought was declared in our community. Marin Municipal Water District reservoirs dipped to just months of remaining supply.

This sobering memory has been forefront in the minds of each member of the MMWD Board of Directors as we work with district staff to implement a roadmap designed to ensure our supply reliability for future droughts.

Last month, the Marin Water Board voted unanimously to proceed with the design and environmental review for a new pipeline and pumping plant to transport excess winter water flows from Sonoma County’s Russian River system to Marin reservoirs — truly a milestone moment.

Our decision follows months of work to analyze and ultimately narrow a list of longer-term water supply options.

The preferred project includes a 36-inch pipeline that would deliver up to 3,800 acre-feet of water annually in its first phase, while a latter phase provides up to 8,100 acre-feet per year. When integrated with other projects identified within our roadmap, it closes a sizable gap in our overall supply needs.

While no project is perfect, there are a number of reasons that make winter water conveyance a big win for everyone:

• It captures excess water flow. This winter water source is not reliant on Sonoma County’s stored supply but instead capitalizes on rainfall and excess river flows, which currently stream out to the Pacific Ocean. Historical records show that, even during drought years, there are plentiful water supplies in the Russian River between October and May resulting from winter rainfall — even after accounting for the in-stream water required to support aquatic life.

• It provides regional benefits. It includes the infrastructure needed to capture and move excess water to be stored in Marin Water’s reservoirs for later use, adding to the resilience of the North Bay’s overall water supply during droughts. Currently, there is no way to transport excess Russian River water to our reservoirs to store for later use. This project would change that.

• It’s the best return-on-investment rate. It is the most cost-effective, large-scale project identified. Other potential projects, such as a modest-sized desalination plant or expansion of one of our existing reservoirs, would cost at least three times as much.

• It offers a concise timeline. The system could be operational in a few years. The other large-scale projects that have been under district consideration — desalination and major reservoir expansion — would likely require a decade or more to implement due to project complexities, as well as environmental and permitting requirements.

While there are promising aspects to these projects today, cost, complexity and extended timelines make these good options for continued exploration while the winter water conveyance project could provide the security and time needed to develop these complex, longer-term projects.

• It enables additional supply potential. The conveyance system could augment a future water supply project. As MMWD continues to investigate the feasibility of expanding reservoirs, directors have asked staff to focus that effort on the modifications of existing spillways and possible expansion of Kent Lake.

While we begin the next phase of work on winter water conveyance, it’s important to note that supply resiliency is an ongoing team effort. To that end, we also maintain our commitment to building supply by partnering with our customers through robust and innovative water efficiency programs — programs that have already helped reduce projected future annual needs by 2,000 acre-feet.

We will also continue to work through the design and environmental review for a project that will raise the Nicasio Reservoir’s spillway and continue improvements within our system that achieve additional water supply gains. Finally, MMWD will continue to monitor desalination advances and cost and pursue outside funding opportunities for recycled water projects that make sense for our service area.

As Marin Water advances efforts on these strategic solutions, we will seek to always look forward, to remain adaptive to changing conditions, and to recognize that when we bind together, we can do amazing things.

To learn more about winter water conveyance and all our supply roadmap efforts, visit bit.ly/3Xm1W9A.

Jed Smith is vice president of the Marin Municipal Water District Board of Directors. His commentary was submitted on behalf of the entire board.