Lafayette Reservoir Erosion Control – Lafayette CA

Description

The view of the Lafayette Reservoir from Mount Diablo is framed by Monterey pines, softening the massive dam. The Civilian Conservation Corps (CCC) planted these trees in the mid-1930s to stabilize the slopes around the dam and to prevent silting and soil erosion of the watershed.

Construction began in 1927, when the Lafayette Reservoir was developed by the East Bay Municipal District (EBMUD) to supplement local water supplies.

The original earthen dam collapsed in September 1928, creating cracks across its crest and face. Subsequent investigations found that the wrong type of soil had been used to build the structure. With officials on edge following the March 12, 1928 collapse of the St. Francis Dam in Los Angeles County, which killed 600 people, work on the Lafayette dam stopped for three years, as engineers redesigned the structure.

It was completed in 1933 as a shorter and wider structure, holding only one third of its originally planned capacity.

During the mid-1930s, three CCC camps attached to the Soil Conservation Service (SCS) worked with EBMUD to improve the watershed. This included building roads, constructing erosion control features, protecting stream banks, planting trees, and clearing forests and undergrowth for fire protection. In 1934, as part of the program, the CCC planted mixed pine and Douglas fir along the slopes of San Pablo Reservoir. A year later, the SCS started 5,000 Monterey pine seedlings for use at other reservoirs. Many of these pines, a non-native to the area, were used to stabilize the slopes around Lafayette Reservoir. As of 1940, the program had planted 57,000 trees within EBMUD’s holdings.

The pines at the Lafayette Reservoir later became an amenity when it opened to public as a recreational area in 1964. Nearly 80 years old, the Lafayette Reservoir Monterey pines are nearing the end of their life cycle. While supporting wildlife, the pine stands exhibit little natural regeneration. Currently, a forest thinning program is removing some of them at the reservoir. Similar stands of trees planted by the CCC eight decades ago at other EBMUD facilities are slated for elimination under district’s Watershed Master Plan.