The County is looking to restore 50 to 110 acres to natural wetlands around Deer Island, located along Novato Creek behind the Vintage Oaks shopping center.
The Marin County Flood Control and Water Conservation District has received a $520,000 grant through the San Francisco Bay Restoration Authority Measure AA. The funding will be used for the design and environmental compliance phase of the proposed Deer Island Basin Tidal Wetlands Restoration Project in Novato.
A view of the wetlands at Deer Island in Novato. The County is looking to restore 50 to 110 acres to natural wetlands around Deer Island, located along Novato Creek behind the Vintage Oaks shopping center. The proposed project has now begun the design phase and is expected to wrap up that work by early 2020. It would restore 50 to 110 acres to natural wetlands around Deer Island, located along Novato Creek behind the Vintage Oaks shopping center. The project could also restore an additional 35 to 45 acres by potentially removing levees from Ducks Bill and Herons Beak ponds, which are adjacent to Novato Creek.
If such changes to the area were to be made, it is expected to increase the tidal area and thereby improve floodplain functionality. The potential improvements would benefit the Novato watershed area, known as Flood Control Zone 1 (FCZ1), not only from an ecological habitat standpoint but also for flood mitigation measures and sea-level rise adaptation.
The proposed plan includes constructing horizontal “ecotone” levees immediately adjacent to the tidal wetlands as a transition zone for sea-level rise conditions, fundamentally improving the resiliency of the marsh wetlands. The expansion of wetland area would naturally improve flood mitigation for FCZ1 by allowing for the dispersion of floodwaters during storm events and king tides.
“Restoring the area to its natural state is a significant undertaking and it is not going to happen overnight,” said Roger Leventhal, Marin County Flood Control District’s Senior Civil Engineer. “It may take years for the restored areas to return to a more natural tidal system, but we’ll experience those benefits and it’ll be a great asset for future generations.”
Deer Island sits at a critical junction of freshwater and saltwater where Novato Creek enters San Pablo Bay. The location is one of only a handful in the Bay Area that still has the potential to restore tidal marsh within this freshwater/saltwater mixing zone. Such zones are important because they provide a unique habitat for wildlife. A wide variety of threatened and endangered species inhabit this complex marsh ecosystem. The vital nesting and breeding grounds for these species have been lost over the decades to land developments, including ranching and agricultural areas.
If a cost-effective design were to be determined and pass the California Environmental Quality Act process, the project would seek permitting from regulatory agencies for the work. The permitting phase would be eligible for an additional $110,000 in Measure AA grant funding. After attaining the permits, actual implementation of the project would need to wait until new funding can be identified. Currently, there are no FCZ1 funds available for construction.
Measure AA is available to all nine Bay Area counties in the form of an annual, competitive grant application process. Because of this, here is no guarantee that funds will be awarded to FCZ1 in any given year, nor to any of the other flood control zones under the District’s supervision.
While the Deer Island restoration project costs are not known at this time, they are anticipated to be somewhere in the range of $8 million to $12 million. As it is unlikely that the District would be awarded the entire funding needed for construction from Measure AA, the District will pursue additional grant funding sources to offset the costs.