Your Water's Journey
From Source to Tap
It all starts with a raindrop on the Mount Tamalpais Watershed. Learn more about the complex local system your water travels through to ensure it is clean, safe and delivered to your tap every time you need it. Use the buttons below to navigate to various steps of our water's journey.
Collected on the watershed and the hills of west Marin
Rain fills five reservoirs on the Mount Tamalpais Watershed and two in the west Marin County hills. District staff steward these 22,000 acres, leveraging outside funding sources to keep consumer costs low while working to reduce wildfire intensity and promote forest health. The costly work is critical to help foster a resilient, healthy watershed -- the foundation of 75% of the water produced for our customers. To reliably serve all of central and southern Marin, we maintain a partnership with Sonoma Water to purchase fresh drinking water from the Russian River.
Flows from our reservoirs
Using either gravity or energy-intensive pump stations, water is pumped from our reservoirs to one of our treatment plants. Trained Marin Water staff consistently test source water in our reservoirs, and employees at our treatment plants monitor flows into – and out of – the treatment facilities as part of a carefully choreographed operation used to ensure a ready water supply for residents in even the most far-flung portions of our service area. Although water use fluctuates daily, and is trending downward overall, the District’s costs to deliver that water are fixed.
Imported and blended
Imported water from the Russian River travels south to Marin County and is blended with the District’s reservoir water. The Russian River water supply originates from rainfall that flows into Lake Sonoma and Lake Mendocino, and is naturally filtered through 80 feet of sand beds adjacent to the river.
Delivered to your tap
Water flows from our main water line toward the customer’s property, passing through one of 62,000 water meters before being delivered to the customer’s taps, ending the District’s work. The customer is responsible for the portion of pipes within their property’s boundaries. The entire journey – from rainfall to faucet – takes about 24 hours. For Marin Water, serving our customers is all in a day’s work.