A 32-unit building is going up at Tam Junction. Here's the story behind it.

What's happening: A 32-unit apartment building at 156 Shoreline Highway had all five stories built, with its exterior structure nearly complete, when the Briefing visited the site on Tuesday. This piece looks back at how it got there, a housing fight that began in Marin City, and what county records show about flooding and parking at the new site.

How it got here: In November 2020 the county approved 74 affordable apartments at 825 Drake Avenue in Marin City under SB 35, a state law that removed its discretion to reject qualifying projects. It was the first project in Marin to qualify for streamlined approval under SB 35, the Marin IJ reported at the time.

Thirty-seven members of the public spoke at a March 21, 2023 hearing on tax-exempt bonds for the building, and supervisors voted 3-2 to approve them, according to the Board's minutes. Supervisor Stephanie Moulton-Peters, whose district includes Marin City and Tam Junction, and Eric Lucan voted no.

After Marin City residents raised concerns about the building's size, the county negotiated a smaller, 42-unit project at Drake, with the remaining 32 units built at Shoreline Highway, according to the county's February 2025 news release. The 74-unit Drake project was already fully approved with building permits issued, and if the Shoreline arrangement fell through, the county said the larger project could still go forward in Marin City, according to a county FAQ.

Supervisors approved the arrangement unanimously on Feb. 11, 2025, according to the meeting minutes. "Reducing the Marin City project to 42 instead of 74 is a significant concession," Moulton-Peters said at the time, according to the release. She told the Briefing that dividing a project this way was "unprecedented."

The Shoreline building was approved under the state's Housing Accountability Act and Density Bonus Law, not SB 35, Principal Planner Immanuel Bereket told the Briefing. The Marin County Planning Commission approved it on May 29, 2025, according to its adopted resolution. The site is in unincorporated Mill Valley, so the county decided, not the Mill Valley City Council.

Flooding: The county's MarinMap viewer lists the parcel in flood zone AE, the federal government's mapped 1-percent-annual-chance floodplain, with a base flood elevation of 10 feet. The same viewer lists other downtown Mill Valley addresses in flood zone AE, including Depot Cafe and Mill Valley Market, which therefore require flood insurance.

Because the property sits entirely within that zone, the project is subject to Marin County Code section 23.09, Floodplain Management, Bereket said. New construction there must have its lowest floor built above the base flood elevation, certified by a registered land surveyor, civil engineer or architect. The building's finished floor is set at 11 feet, according to the developer's plans, and the developer's engineer has submitted documentation asserting the building meets the county's standard, Bereket told the Briefing.

Community Development Agency Director Sarah Jones defended the site's suitability in a county news release announcing the two-site agreement. "This is the kind of place where Marin can accommodate the housing that the county needs," Jones said. "It has good transportation access and is near businesses and amenities."

The county's Manzanita Park and Ride lot near Tam Junction has experienced flooding during past king tide events, according to a county news release from January 2026. Forecasters expect a strong El Niño this winter, which the National Oceanic and Atmospheric Administration says could temporarily raise sea levels in California by about 6-12 inches. That would come on top of whatever king tides and storms the winter brings.

Moulton-Peters told the Briefing that Tam Junction "will need a comprehensive plan for sea level rise" and that the area's businesses and homes are already exposed. "We are not going to solve sea level rise property by property," she said. Building anything new in an area that will eventually need that kind of protection isn't ideal, she said, but the area needs one comprehensive fix rather than a solution for each new project.

Parking: The county's approved condition sets parking at seven spaces, against the 51 spaces county code otherwise requires, according to the resolution. State density bonus law allowed the reduction, and to deny it the county would have needed to find a specific, adverse safety impact, which the resolution says the record doesn't show. A required parking management plan, which could use "available County-owned land," per the resolution, has not been filed, Bereket said.

Moulton-Peters told the Briefing that a nearby county-owned parcel, originally acquired from Caltrans, has been discussed as a possible ground lease for parking, not a sale, until the county needs the land back for a future project.

What's next: Units will be restricted to households earning up to 80 percent of the area median income, according to the resolution. The Briefing has not seen an executed parking plan or a move-in date, and will report when one is filed.

📨 Know anyone who drives on Shoreline Highway and has talked about this project? Forward this newsletter to them.

City council voted 5-0 Monday to introduce an ordinance banning retail tobacco sales entirely, moving the enforcement date up from a suggested April 1 to February 1, 2027 to align with neighboring Corte Madera. A full piece on what the ordinance does, how council got here, and the debate over timing and retailer impact runs Sunday.

Marin County parks commissioners vote Thursday on whether to recommend allowing Class 1 e-bikes on Open Space District preserves wherever conventional bicycles are already permitted, according to a staff report and presentation from Park and Open Space Superintendent Ari Golan. Class 2 and Class 3 e-bikes would stay banned.

If approved, the recommendation moves to the district's Board of Directors for a final vote. Staff pointed to a feedback survey that drew more than 2,400 responses between May and September, with 68% expressing support and 29% opposed, and said improved access for older adults and people with limited mobility was the benefit cited most often.

The preserves at stake, including Alto Bowl, Camino Alto and Blithedale Summit, ring Mill Valley to the east and north and fall under Marin County Parks. A separate agency, Marin Water, manages the Mt. Tamalpais watershed land nearby, including Double Bowknot and West Point Inn, and has run its own Class 1 e-bike trial on that watershed land since 2025. Read that story here.

Marin County is also in charge of parks in Homestead Valley which aren’t open preserves and are not allowing e-bikes. The same goes for National Park land and State Parks to the south and west of Tam Valley and Homestead Valley.

👶 Toddler Storytime, Mill Valley Public Library, 10:15–10:45am. Books, songs, and rhymes in the Outdoor Amphitheater at 375 Throckmorton Ave for toddlers and caregivers. Free entry; no registration required.

👁️ Surprise Yourself: Creation and Perception w/ Candis & Cayen, O’Hanlon Center for the Arts, 11:30am–1:30pm. Interactive group discussion exploring Ann O’Hanlon’s book seeing/perception to re-examine how we look at our own art and the work of others at 616 Throckmorton Ave.

🎬 Plastic Detox: Screening & Discussion, Mill Valley Public Library, 6–8pm. Plastic Free Marin hosts a screening of the documentary The Plastic Detox, followed by a community discussion on plastic impacts and human health in the Creekside Room at 375 Throckmorton Ave. Free entry; registration required.

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