Marin County’s efforts to avoid running out of water by building a pipeline across the Richmond-San Rafael bridge are adding new complications to several bridge projects already years in the making, including the bicycle pathway and the potential for a third westbound commuter lane.
“It raises uncertainty,” said Marin County Supervisor Damon Connolly, who serves on the Transportation Authority Board of Commissioners. “I think the public is very interested in what is coming out of the water district in terms of options and feasibility.”
Marin Municipal Water District is proposing to build an up to $90 million, 8-mile pipeline over the bridge from Richmond into Marin that could pump in water purchased from Sacramento Valley agricultural producers.
Design options being studied by Caltrans include either strapping the pipeline underneath the top deck of the bridge or laying it along the shoulder of the top deck where the bicycle and pedestrian path has resided since late 2019. There are also conversations underway about whether to make the pipeline a permanent feature of the bridge to be used for future droughts. A pipeline was installed on the top deck in 1977 when the county last faced a water shortage. The pipeline was removed in 1982 at the request of Caltrans to restore traffic to the blocked third lane.
The Transportation Authority of Marin — the county’s traffic congestion management agency — has been studying several projects aimed at addressing traffic flow on the bridge. These include potentially closing the bike path during peak morning commute hours on weekdays from 5 a.m. to 11 a.m. to allow for a third lane of vehicle traffic into Marin.
But the possible addition of a 24-inch diameter pipeline along the bike path as soon as next summer, especially if it were permanent, has raised questions.
In a letter to the district, TAM Executive Director Anne Richman called on water district leaders to select a pipeline configuration that provides the “maximum flexibility for future transportation uses of the bridge.”
“These plans and projects demonstrate the great interest in using all available and appropriate space on the bridge for transportation purposes,” Richman wrote in her Sept. 20 letter to water district General Manager Ben Horenstein. “Therefore, we strongly encourage MMWD to design the potential water pipeline project such that the upper deck can continue to be available for current and future transportation uses.”
Last week, water district staff said they were working with Caltrans to review two configurations of the pipeline to develop a preferred option. Water district Operations Director Paul Sellier said analyses of the bridge have found it can support the pipeline in its current state, including with the existing moveable barrier along the bike path. The question now is where the pipeline would be built.
One option would be to have the pipeline run underneath the top deck of the bridge. The pipeline would need to be at least 16.5-feet above the eastbound traffic below, which Sellier said could be achieved throughout the entire span.
Should the water district choose the bike path route, the pipeline could result in an up to 10-inch incursion into the 10-foot wide pathway, Sellier said.
“That’s not to say that it lessens anybody’s concerns over using the bike path, but it’s just what we’re able to do in terms of design,” Sellier told the district Board of Directors in a Sept. 17 update.
Warren Wells, the policy and planning director with the Marin County Bicycle Coalition, said a 10-inch incursion into the 10-foot wide bike path should not be too much of an inconvenience.
“It would decrease safety slightly,” Wells said, “but I think the necessity of Marin being able to turn on their taps every day probably outweighs that.”
Another complication is the vehicle that is used to slide the moveable concrete barrier along the bike path is wide enough that it occupies part of the space where the pipe would be located, Sellier said.
What concerns Wells and other groups such as Bike East Bay and the Trails for Richmond Action Committee is the Transportation Authority of Marin’s study into whether to close the bike lane during weekday morning commute hours. The authority’s Board of Commissioners met Thursday to hear an update on the study.
The $20 million bicycle and pedestrian path on the Richmond-San Rafael Bridge is part of a nearly five-year pilot project that has been long sought by cycling advocates. The path is set to remain open through the summer of 2024, with local transportation agencies studying its usage and traffic impacts.
Average motor traffic on the bridge in 2019 was 40,997 vehicles on weekdays, 40,872 on Saturday and 37,068 on Sundays, according to data from the Bay Area Toll Authority, which is a partner in the bike path project. Westbound traffic delays on the bridge during weekdays were about 22 minutes in 2019 and expected to rise in 2020 before the onset of the pandemic, according to the Transportation Authority of Marin.
Connolly said traffic is now returning and that pilot test should be shortened, especially given the lower usage of the bike lane during weekdays compared to weekends. In the past 45 days, the average weekday use on the bridge was 145 trips and the average weekend use was 423 trips, according to Bay Area Toll Authority data.
“The fact of a largely empty bike lane during a.m. commute hours while traffic is crawling for our teachers, home health care workers and so many other people cannot be overlooked,” Connolly said. “This is not a single-occupancy vehicle versus bike issue.”
Opening the third upper deck lane to traffic would require bridge improvements on the Marin end ranging from $70 million to $90 million, according to the transportation authority. This project would include widening portions of the bridge relocating the Francisco Boulevard on-ramp and widening portions of Interstate 580.
Another project being eyed is a $310 million project that would create a direct connector between westbound Interstate 580 and southbound Highway 101 in Marin.
Wells said while the weekday numbers are lower, part of that is because the bicycle connections on the Marin side of the bridge are not completed and do not separate cyclists from drivers on roads such as Sir Francis Drake Boulevard.
“It doesn’t seem like a very fair test of its utility,” Wells said. “If you had a new highway that dead-ended at a dirt road you wouldn’t see a lot of people using it.”
The third westbound lane would only lead to more congestion and increase greenhouse gas emissions, Wells said. He said the organization would be open to discussions about using the third lane as a transit-only lane.
“If this were a plan to provide high-frequency, high-capacity transit in that lane, that would be one thing,” Wells said. “Another general-purpose lane or even HOV lane is not that.”
Connolly said he would support the third lane being used as a carpool and transit-only lane.
He said he has his own issues with the proposed project costs, however. The $90 million option to widen the bridge and relocate the Francisco Boulevard offramp would not result in significant travel time savings, Connolly said. The price of the $310 million direct connector project between Interstate 580 and Highway 101 is “astronomical,” he said. Connolly said there should be more exploration of lower-cost options.
“My sense is the high-end dollar amounts contained in the report are a nonstarter,” Connolly said.