Officers are contemplating plans to boost parts of Freeway 101 and Freeway 1 to ease flooding in southern Marin.
A proposed undertaking alongside Freeway 101 would elevate a portion of the southbound lane and offramp on the Marin Metropolis exit; assemble a 700-foot floodwall between the freeway and a stormwater pond; and set up pumping mechanisms to extend circulate from the pond into the Richardson Bay, in keeping with Caltrans and state Sen. Mike McGuire.
The undertaking additionally contains an effort to boost Freeway 1 north of the Manzanita commuter lot, which is closed routinely due to flooding. An automated tide gate could be put in on the lot and drainage could be reconstructed. The Mill-Valley-Sausalito multiuse path additionally could be raised by about 3 ft.
McGuire, whose district contains Marin County, held a briefing on the proposal for about 20 individuals on the Marin Gateway Buying Middle in Marin Metropolis on Thursday. He mentioned the initiatives may value $75 million to $100 million, which he known as a tough estimate till an environmental evaluation was full.
McGuire described Marin Metropolis because the “first precedence” for any work.
“We wish to ensure we’re all on the identical web page about what works and what must be carried out,” McGuire mentioned. “It’s a generational subject and it must cease.”
Caltrans District 4 Director Dina El-Tawansy famous the undertaking was in a draft part and can doubtless require an environmental engineering evaluation, which is predicted to take one to 2 years.
“We notice within the brief time period one thing has to occur,” she mentioned.
McGuire mentioned looking for funding from the California Transportation Fee or neighboring municipalities may pace efforts due to the lengthy ready record for Caltrans-funded initiatives.
McGuire mentioned “short-term methods” may instantly make an affect. He mentioned a “muscle wall,” or flood barrier, was not too long ago put in between the pond and the freeway. A field culvert below Freeway 101 and a slide gate on the basin had been additionally not too long ago repaired by Caltrans. He mentioned a county undertaking was in progress to assemble a pump station within the basin and set up a secondary culvert below Freeway 101.
The group toured the stormwater pond and freeway part the place the adjustments had been proposed earlier than driving to the commuter lot to get a way of what was deliberate there.
Latest enhancements on the commuter lot included the set up of a drainage inlet and culvert slide gates close to Freeway 101, the set up of a warning signal, electrical replacements on close by site visitors alerts and restore to broken pavement, a Caltrans doc mentioned.
Members of the Marin Metropolis Neighborhood Providers District, together with Damian Morgan and Terrie Harris-Inexperienced, urged the officers to make fast work of the issue due to the general public well being impacts of persistent flooding.
“Flooding shouldn't be new to Marin Metropolis, not new to southern Marin,” Morgan mentioned. “It is a monumental day and we're simply getting began.”
Harris-Inexperienced mentioned she needs the pond to be examined for contaminants.
“The general public well being affect is disastrous,” she mentioned. “Marin Metropolis points appear to be placed on the again burner.”
Marin County Supervisor Stephanie Moulton-Peters, whose district contains Marin Metropolis, mentioned extreme flooding in Marin Metropolis on Oct. 24 nearly shut down the group. Residents trudged via standing water and had been blocked from leaving the world.
“We lastly realized one thing needed to be carried out,” Moulton-Peters mentioned. “Now we have to get this off the bottom.”