It Can’t Be Done… or Can It? A look (so far) at the adaptively managed Lee Vining Rockfall Project

Spring 2016 Ecesis, Volume 26, Issue 1

From top, photos courtesy Michael Hogan: A very steep and otherwise challenging slope to stabilize — tufa and old volcanic ash with a pH level of 8.3. The same slope after implementation, looking straight up, shows visible progress in vegetation establishment. Monitoring at Lee Vining to see what’s working.  

From top, photos courtesy Michael Hogan: A very steep and otherwise challenging slope to stabilize — tufa and old volcanic ash with a pH level of 8.3. The same slope after implementation, looking straight up, shows visible progress in vegetation establishment. Monitoring at Lee Vining to see what’s working.  

What do you get when you mix Caltrans, an environmental advocacy group, tufa soil (pH8.3), a 60-degree slope, and the need to make sure you can effectively stabilize that slope? 

Usually, you would get an “it can’t be done” response, with innumerable reasons why: Lack of precedent for slopes that steep being effectively revegetated, Caltrans internal constraints (e.g., contracting, multi-year funding, potential lack of interest, and lack of confidence in a viable result), lack of trust between the players, nearly complete lack of summer rain, and on and on. 

But in a very unusual and perhaps unique project, Caltrans and the Mono Lake Committee (MLC) have embarked on a multi-year, adaptively managed project near Lee Vining on Highway 395 called the Lee Vining Rockfall Project. The project has been in play for over three years — starting with small pots of soil to test amendment-plan responses, then moving to small- and medium-sized test plots on the actual project site, and from there to full-scale implementation — and yet there are still many reasons why it could fail. But unlike most other projects of this sort, which rely on applying BMPs and expert-opinion-based treatment, the Rockfall Project is not relying on prediction alone. By basing treatment on actual results with very specific success criteria — with each step scaling up the results of the previous step — confidence is built because the probability of success is based on actual proof of treatments.

The incentive for this adaptive approach comes from the fact that MLC reminded Caltrans that Mono Lake is a National Scenic Area and as such requires visual assessment to be a primary element in roadside and other projects. Thus, MLC asked that the Rockfall Project guarantee, to the greatest extent possible, a viable native plant community. Then they suggested that Caltrans consider an alternative approach to the standard hydroseed (or “spray and pray”) method of applying seed to a bare slope and then covering it with a kind of fabric. Caltrans District 9 staff rose to the occasion and addressed the challenge head on. By engaging outside help, they agreed to a multi-year process, despite the many constraints they had to address within the agency. The testing started with the soil, using a number of amendments, incorporation techniques, and specialized temporary irrigation.

Ultimately — as the Rockfall Project is only half built — the outcome of the project is not yet known. But if initial results are any indication, this project will show visible progress in a year or two. Already the grasses, seeded shrubs, and forbs are emerging everywhere and the main concern — erosion, even on the 60-degree portion of the slopes — is generally non-existent. And perhaps most importantly, Caltrans and the Mono Lake Committee have gained a degree of trust that is hard to find between two entities with seemingly different agendas. Rather than pushing and pulling on each other to move forward their specific versions of “what is” (and spending finite resources on attorneys), they have come together to actually explore mutual goals as a team, and in the end funded a project with outcomes and learning. — by Michael Hogan1, Integrated Environmental Restoration Services, Inc., former SERCAL President, Conference Chair, and long-time Board member