The cost of the environmental review of this Project totaled approximately $80,000, to be funded by the District with Flood Control Zone 1 funds (50 percent) and American Rivers, Inc. (American Rivers) State Grant Funds and other private funds (50 percent).

During the 1960s and early 1970s, approximately 7.9 miles of Marsh Creek from the mouth of the creek near Big Break in Oakley to the Dry Creek confluence in Brentwood were channelized into steep earthen and armored trapezoidal flood control channels to provide conveyance capacity and riparian vegetation was removed. The channel was designed for a 50-year flood event in an agricultural setting. Over the last 25 years, the population of the lower Marsh Creek watershed has increased dramatically, transforming the watershed into a dense residential and commercial area, covering open space with impervious surfaces, substantially increasing runoff volume and degrading water quality. The District has constructed detention basins on each of Marsh Creek’s three tributaries (Dry, Deer, and Sand Creeks) to accommodate increased run-off associated with urban development and impervious surfaces; however, urban and agricultural runoff remain issues.  
  
The Three Creeks Parkway Project described in the Initial Study/Mitigated Negative Declaration (IS/MND) combines two separate projects. The first is the Three Creeks Restoration Project on Marsh Creek, in which the District partnered with American Rivers to apply for and receive $744,404 in DWR Urban Streams Grant Funding. The project limits of that project are from the Union Pacific Railroad tracks crossing of Marsh Creek to its confluence with Sand Creek (identified as the Lower Reach in the IS/MND). The second project is Phase 2 of the Marsh Creek Widening Project. The District is the sponsor of that project, and American Rivers is providing the District with State grant funds and other private funds to provide a multi-benefit flood control project. The project limits of the second project are from Sand Creek to just upstream of Dainty Avenue (identified as the Middle and Upper Reaches in the IS/MND). The two projects were addressed together because they are adjacent and cumulative impacts needed to be considered.  
  
The objective of the Project would be to improve the ecological functions of Marsh Creek by reducing flow velocities, creating wetlands, and restoring riparian habitat. Although much of the watershed has been constrained by urbanization, the Project site is the longest remaining stretch of undeveloped land along the creek where there is still an opportunity to widen the channel and provide a more natural creek system that is connected to the historic floodplain that can be enjoyed by trail users.  
  
The District, in partnership with American Rivers, developed the proposal to widen and restore approximately 4,000 linear feet of the Marsh Creek channel identified in three reaches (Upper, Middle, Lower) from Dainty Avenue downstream to the Union Pacific Railroad tracks with a floodplain (or in sections where more constrained, floodplain benches) that will meet the District’s standards for 100-year flood protection and restore native riparian vegetation and enhance habitats and recreation. The segment just upstream of Dainty Avenue was widened in 2000 by the District. Native riparian vegetation may also be planted in this segment as part of the Project to provide a continuous riparian corridor with the existing riparian vegetation upstream of this segment.  
  
The Project calls for widening the creek above the low-flow channel, but some areas will require work within the low-flow channel in order to create in-stream habitat using boulders and large woody debris, and to place rock slope protection. The Project would also include slight relocation of the existing East Bay Regional Park District Marsh Creek trail along the top of the eastern bank to the new top of grade from Dainty Avenue to Sand Creek (in the Upper and Middle Reaches). The trail from Sand Creek to the railroad tracks (in the Lower Reach) is to be relocated by the adjacent subdivision developer (Pulte) separately from the Project; however, the Project would reduce the gradient of the steep slope between the creek and the trail in this reach and would provide a new unpaved foot trail within the floodplain benches. The relocated trail section within the Upper Reach would be routed to pass under the Central Boulevard bridge.  
  
Approval of the Project is not recommended at this time because the District and American Rivers have not yet completed their negotiation of a separate agreement that outlines their respective obligations under the DWR Urban Streams grant agreement (for the Three Creeks Restoration Project) and terms and conditions that will apply to the work that American Rivers plans to perform. Without this agreement, the District would become obligated to perform the obligations of both parties under the grant agreement upon approval of the Project. District staff also anticipates the need for an agreement that sets forth the District’s and American Rivers’ roles under the Marsh Creek Widening Phase 2 Project. District staff anticipates returning to the Board in February 2017 to seek Board approval of the agreement(s) and the Project.

If the Mitigated Negative Declaration and Mitigation Monitoring and Reporting Program are not adopted before October 1, 2016, American Rivers may lose conditionally-approved grant funding for the Project.