Sunrise light on a grove of tufa towers emerging from the water of Mono Lake with soft green and dusty-red wild grasses in the foreground, Canada geese in the shallow water with reflections of the rocky towers, and desert hills in the distance.

Caltrans rockfall project now in progress

This post was written by Lisa Cutting, 2002-2020 Eastern Sierra Policy Director, 2000-2001 Environmental Resource Coordinator, and 1999 Mono Lake Intern.

After three years of meetings and discussions, in-depth analysis and testing, expert recommendations and collaboration, the Lee Vining Rockfall Safety Project is underway.

The Lee Vining Rockfall Safety Project will reduce rocks falling onto the highway while improving the visual quality of old roadcuts at the same time. Photo by Arya Degenhardt.
The Lee Vining Rockfall Safety Project will reduce rocks falling onto the highway while improving the visual quality of old roadcuts at the same time. Photo by Arya Degenhardt.

The California Department of Transportation (Caltrans) project will improve motorist safety by reducing rockfall incidents along a one-mile section of Highway 395 near Old Marina. The project will stabilize and revegetate six eroded slopes using a combination of anchored mesh, soil rehabilitation, and revegetation tailored specifically to the Mono Basin’s unique soil composition.

More than 650 Mono Lake Committee supporters commented on the proposed project, advocating for an effective and ecologically sensitive project with minimal visual and no water quality impacts.

What drivers should expect

The project area has steep slopes to the west and the Mono Lake Tufa State Natural Reserve to the east so space is tight and requires closing one lane of the highway to stage and maneuver equipment. Temporary traffic control signals will operate 24 hours a day for the duration of the project and motorists should expect delays of up to 20 minutes. At night the signals will be activated by motion sensors to reduce wait time.

In addition, the project will include two eight-day periods of complete road closure for up to one hour per day, Monday through Thursday mornings between 6:00am and 7:00am. In order to minimize the number of people affected by the delays, the hour-long closures will not take place on Fridays, Saturdays, or Sundays. Specific complete-closure dates will be communicated well in advance on Caltrans’ electronic highway information signs, temporary signage, and online.

The Mono Lake Committee Information Center & Bookstore as well as will serve as a source for closure information and updates as the project progresses this summer.

Construction timeline

The formal project schedule outlines construction during the 2015 and 2016 summer seasons. Since the contractor has been able to get an earlier start than originally planned, the project may be completed earlier—perhaps even before the snow falls this coming autumn. Of course, there are many unknown factors that could influence the project timeline, most notably weather and unforeseen complications that may arise during construction.

How the project area will look this year

Now that traffic control systems and erosion control safeguards are in place, Caltrans has started work on the two northernmost, most complex slopes, where they have begun rock removal, or “scaling,” to prepare the slopes for anchored mesh. Over 3,000 anchors must be drilled into three of the six slopes in order to secure the mesh. The mesh will both stabilize loose material and help hold soil amendments and seed mixtures in place to give plants a chance to establish.

Although some amount of rock removal has to occur on all six slopes, the three southern slopes do not need anchored mesh, and will be stabilized through soil rehabilitation and revegetation alone. Over the past two years Caltrans has methodically tested a range of revegetation options, and has tailored the project to use the best method for each slope.

This summer we expect the slopes to look their worst, and they will be somewhat of a shock to people who know the area and the view along the lakeshore well. Some slopes will be cleared of all existing vegetation and the anchored mesh will be clearly visible. But, as we know from other restoration projects in the Mono Basin, doing things right takes time, and in the long-term the slopes will blend in with the adjacent existing vegetation. The area will ultimately be much safer and will look better than it has in the 80 years since the slopes were originally cut to make room for the highway.

For the Mono Lake Committee this carefully-planned, long-range approach to fixing both the rockfall problem and the visual scars of the past is a good example of a win-win collaborative solution to this critical issue.

This post was also published as an article in the Summer 2015 Mono Lake Newsletter.