CANCELED – Zone 7 Advisory Board Meeting: June 26, 2024
6:30 pm
FLOOD CONTROL ZONE 7 ADVISORY BOARD
June 26, 2024
STAFF REPORT
This document is a written update to the Flood Zone 7 Advisory Board in lieu of meeting, as there are no action items needed from the board at this time. Questions and comments can be sent to floodinquiry@marincounty.org.
Item 1. Review Meeting Minutes: March 27, 2024
Find minutes here
Item 2. Annual and Preventive Maintenance Program Update
In addition to the pre-winter activities listed below, District maintenance crews check the trash racks and pump stations before, during, and after storms. For questions, email floodinquiry@marincounty.org.
a. Pump Stations – Preventive maintenance at all pump stations takes place every year and includes the inspection, testing, and as needed replacement of electrical and mechanical components. Additionally, individual pumps and motors are typically removed and serviced for major preventive maintenance on a six-year interval at each of the Zone’s five stations. This work is taking place this summer for certain pumps and their motors at Stations 1, 2, 4, and 5. The contract cost for refurbishment of these pumps is $76,835 this year, including a 10% contingency. The pumps have been pulled out of the pump stations and are currently being evaluated. If the needs of these pumps exceed the available budget, we will return to the advisory board with a recommended budget adjustment.
b. Vegetation Maintenance – Vegetation in the ditch between Birch and Mabry is trimmed in early fall to increase flow capacity. The ditch’s banks are mowed in the spring for fire fuel reduction (scheduled week of June 22). In the summer a section of Castro Ditch will be cleared of debris and low or downed branches will be trimmed or removed.
c. Levee Maintenance – The inner levee adjacent to homes at the Open Space preserve was mowed by the Parks Department. Gopher control and filling of burrows are completed in the summer and a second phase may be needed in September. Conditions of the inner levee are continually inspected throughout the winter during storms and/or high tides, when seepage is most evident.
The District is also working with additional property owners along Vendola Drive to make repairs where the timber-reinforced berm (TRB) wall materials are deteriorating. See Item 3 for details on this effort.
Item 3. Timber-Reinforced Berm Repair Update
Background: A comprehensive inspection of the timber-reinforced berm (TRB) and levee along Vendola Drive was completed in August 2023. Supplemented by updates made since then, 21 parcels were identified as high priority for maintenance – specifically their remaining useful life is estimated to be 0-5 years. In fall of 2023, of those 21 parcels, 545 feet of the high priority sections were maintained. The expected useful life of newly maintained sections is 10-15 years.
Your Board recommended a $400,000 budget for repair work this coming year, and also requested investigation of any possible cost-saving alternatives.
Update: District staff explored several alternatives to the method of maintenance employed last year. At this point staff recommend that the County’s Road Maintenance Division, which already conducts a lot of the District’s annual maintenance work in other zones, conduct the timber-reinforced berm maintenance this year with support from the Conservation Corps North Bay and District staff for permit compliance and quality assurance. This maintenance will be performed on an annual basis by the Road Maintenance Division moving forward. They have the qualifications to conduct the work including experienced carpenters and nesting bird protection training.
Item 4. Schedule Next Meeting
The Flood Zone 7 Advisory Board adopted a regular meeting schedule on the last Wednesday of the months of March, June, September, and December. The next meeting is tentatively scheduled for September 25. Additional special meetings may be called if a budget adjustment or other urgent need is identified.