Tractor truck mowing on Arroyo De La Laguna
At Work Maintaining Your Flood Protection System
17,220 feet of access road and drainage inspected and repaired
5,700 feet of concrete-lined channel cleared of vegetation and debris
210,720 feet of open channel mowed to reduce fire and public safety hazards
2017 Flood Recovery Continues
Zone 7 continues to repair flood protection sites damaged during the record-breaking 2017 storm season which brought significant rainfall and localized flooding throughout the Tri-Valley. Our flood protection system saw damage to channel banks, concrete structures, and maintenance roads, threatening utility lines and infrastructure.
Our team made significant progress in 2021 repairing fourteen bank slide sites.
Since February 2017, 98 of the 208 originally identified bank slide sites have been successfully repaired in Zone 7’s Rehabilitation of Flood Control Channels, Phases 1, 2 and 3 and by the U.S. Army Corps of Engineers. With the 9 left to-be-repaired sites in Phase 3, this will bring the total repaired sites to 107. There are 101 sites that were removed from the field-documented 208 potential issues, as these were incorporated into Zone 7’s routine maintenance program.
Goat in the Zone
After a successful pilot program, Zone 7 began conducting goat grazing activities at a limited number of sites to supplement our flood and fire preparedness efforts. The goats eat overgrown vegetation that gets dry in summer months and is at risk for fire, and blocks the flow of water in flood channels during the rainy season. These helpful goats are a great addition to our preparedness efforts and a helpful addition to our Maintenance Program. The goats “work” along select access roads and channels to control the growth of herbaceous vegetation and invasive weeds, reduce fire fuel loads, and maintain grassland habitat for special-status species. In total, seven different sites were grazed this year, totaling approximately 117 acres.
Significant Achievements In Flood Protection Program
Continued Routine Maintenance Program
As a part of the Routine Maintenance Program (RMP) for flood protection facilities, staff continued pursuing programmatic permits from California Department of Fish and Wildlife, Regional Water Quality Control Board, and the United States Army Corps of Engineers.
Bank repair planning
Staff prioritized district wide bank repairs according to level of risk presented by each site and continued to plan for an additional 4 repairs in 2022. Flood protection staff regularly monitor the sites pending repair for any changes in condition. Permits are already secured.
Arroyo Mocho Stanley Reach Bank Stabilization Project progress
The Arroyo Mocho Stanley Reach Bank Stabilization Project was authorized for construction in April 2021 and began in May 2021. At the end of June, approximately 50% of the channel restoration had been completed. Work is ahead of schedule to be completed in 2021, instead of 2022.
Awarded US Geological Survey grant
In the Fall of 2020, Zone 7 applied to the US Geological Survey (USGS) 3D Elevation Program for a grant to acquire high-definition elevation data and gather important topography information of our flood channels. Zone 7 was awarded a grant in early 2021 and will work in collaboration with the USGS to share data, LiDAR acquisition and processing costs.
The Bank Stabilization, Arroyo Del Valle Project
The team continued work on the the bank stabilization of Arroyo Del Valle and restored 220 linear feet of levee and added 150 ft of geogrid support.
6 horizontal drains installed
1 headwall repaired
5 biotechnical repairs
Our maintenance staff coordinated with the City of Livermore and Caltrans for several creek cleanups along the Arroyo Las Positas in Livermore within portions of the channel that have become homeless encampments. We collaborated with local service providers including Block by Block, CityServe, Monthly Miracles, and Open Heart Kitchen to provide services to the unsheltered individuals living within the Creek. Approximately 46 tons of waste and debris was removed from the creek and disposed of in a safe and respectful manner.
Outfall and drain pipe assessment
Staff began an asset inventory and condition assessment of all outfall structures and drain pipes within Zone 7 owned channels using ESRI Survey123 application. The location and condition of each outfall pipe and structure was documented and given an overall condition assessment. To date, 582 outfall structures have been documented within Livermore, Pleasanton, and Dublin. Staff is now collaborating with the cities to coordinate maintenance activities.
In-channel structure maintenance
The team performed routine maintenance including minor concrete repair, crack sealing, and outfall repair on in-channel structures along Pleasanton Canal, Old South San Ramon Creek, Tassajara Creek, and Alamo Canal.
Routine vegetation management work included trimming, pruning, and removal of vegetation and woody debris along access roads, fence lines and in-channel throughout the service area.
Zone In On
What You Can Do
Waiting for a flood? We can hope for rain and be prepared. Get year round tips for staying flood ready at zone7water.com/floodready.