In 2016 and 2017, landslides occurred below Augusta Drive and adjacent to the Moraga Creek in Moraga, which resulted in multi-party property damage and significant degradation of the creek bank.
In 2020, the affected property owners reached legal agreements to develop a coordinated solution that addresses slope movement in the area. As part of those agreements, EBMUD explored the feasibility of repairing the slide area and restoring the creek by constructing an earth retaining system that spans the area of the recent slides. The retaining system would support the hillside below Augusta Drive and protect the integrity of the Town of Moraga’s new Canyon Road Bridge, while providing space for East Bay Regional Park District to restore the trail in the area. To assist with funding, EBMUD was granted a $3 million hazard mitigation grant from the Federal Emergency Management Agency to mitigate hazards in the area, including landslides.
EBMUD has developed a design for the Moraga Creek Flood and Erosion Control Project, which includes installation of two rows of earth retaining systems consisting of 36" and 42" diameter vertical drilled piers with post-tensioned tieback anchors. The piers will be approximately 35- to 58-ft deep and extend into competent ground. The project also includes installation of site drainage improvements, re-grading and revegetation of the slopes, and restoration of the creek banks. Trees will need to be removed, and an appropriate number of trees will be replanted at the project site, with the remainder of the trees planted within EBMUD’s watershed lands in the vicinity of USL reservoir.
Workplan and schedule
EBMUD expects the construction to take place in phases over two seasons. By late 2021 one row of the earth retaining system will be completed. The site will be graded and winterized, and in the following spring 2022, work will resume on the remaining drilled piers and tie backs, followed by creek restoration and revegetation. Work is anticipated to be completed by fall of 2022.
Community Affairs, Kathryn Horn
Emergencies or after-hours, call EBMUD at 866-403-2683
View the March 16, 2021 Community Meeting:
Documents and Publications
|March 16, 2021 Moraga Creek Community Meeting Powerpoint||3.8 MB|