Marin Water advances $1.76M pipeline replacement for 143-year-old mains

Marin Water advances $1.76M pipeline replacement for 143-year-old mainsThe Miracle Mile East project will replace 1,840 feet of leak-prone, thin-walled steel piping in San Rafael, coordinating with city roadworks to mitigate the high costs of construction in a major intersection.

The $1.76 million project will install 12-, 8-, and 6-inch welded steel pipes, replacing infrastructure originally laid in 1883.

High construction costs of $717 per linear foot are attributed to the project's location at the busy intersection of 4th and 2nd Streets.

Marin Water is coordinating the 88-day project with the City of San Rafael’s planned road and bike lane restoration to minimize public disruption.

The district opened construction bids on May 14, with a contract award recommendation expected at a future board meeting.

The Marin Municipal Water District (Marin Water) is moving forward with the Miracle Mile East Pipeline Replacement Project, a $1.76 million capital improvement effort to overhaul aging water infrastructure in the City of San Rafael, California. Discussed during the district's May 14, 2026, Planning Committee meeting, the project involves installing approximately 1,840 feet of new 12-, 8-, and 6-inch welded steel pipe. The new infrastructure will replace leak-prone pipes, some of which were installed 143 years ago in 1883. According to Assistant Engineer Brian Cook, the oldest sections of the existing 12-inch pipeline are made of "lock converse," described as a very thin-walled steel that is no longer standard. The total project budget is $1,761,000, which includes a $1.32 million engineer's estimate alongside contingencies, materials, and district labor. The project's cost equates to approximately $717 per linear foot. Engineering Manager Zach Talbot noted to the board that this price point is on the higher end for the district. The elevated cost is driven by the project's location at a major intersection where 4th Street meets 2nd Street, requiring contractors to cross multiple traffic lanes to make connections. To mitigate public disruption, Marin Water is coordinating the pipeline replacement with the City of San Rafael's upcoming road restoration and bike lane project. Committee members expressed support for this multi-agency coordination, noting it frames the pipeline work as part of a larger community improvement package rather than an isolated disruption. An evaluation for installing recycled water piping was conducted but deemed infeasible, as the nearest existing recycled water pipeline is 2.7 miles away. The district opened construction bids on May 14. The project is expected to last 88 days, with an estimated completion date of August 28, 2026. A second phase, the Miracle Mile West Pipeline Replacement Project, is planned for construction late in 2026.