Redwood Creek Trail Realignment and Dias Ridge Trail Extension Project
**Update (1/7/16): The public review and comment period has been extended by an additional week, and will end on Friday, January 15, 2016.**
The Redwood Creek Trail Realignment and Dias Ridge Extension Trail project includes realigning a section of the Redwood Creek Trail, improvements to the existing Redwood Creek Trail, and construction of a 1,300 linear foot extension to the Dias Ridge Trail. The project is being planned in coordination between the California State Parks and the National Park Service.
The purpose of the proposed action is three-fold: (1) to create a safer and more sustainable trail for visitors; (2) reduce adverse effects of Redwood Creek Trail on Redwood Creek and the multiple drainages to the creek crossed by the trail; and (3) to connect the southern ends of Redwood Creek Trail and Dias Ridge Trail by an extension of the Dias Ridge Trail to create a 5.4 mile circuit. The Project would improve trail conditions and safety for visitors, provide a trail interconnection, reduce maintenance needs, and reduce sediment and improve water quality in Redwood Creek.
The Redwood Creek Trail and Dias Ridge Trails are located in the Redwood Creek watershed in Mount Tamalpais State Park (MTSP) and Golden Gate National Recreation Area (GGNRA). This watershed is a region of significant biodiversity and provides habitat for listed species including coho salmon, steelhead, California-red legged frog, and Northern spotted owls.
The current alignment of the Redwood Creek Trail parallels Redwood Creek for much of its length and crosses the creek via bridges and horse fords and crosses tributaries via culverts and crib walls. The alignment of much of the trail lies within the floodplain and is likely increasing the supply of fine sediment loads to Redwood Creek. Increased fine sediment loads have a direct negative impact to the viability of listed species. The existing horse fords cross the creek bed via trails on the creek banks contributing to fine sediment delivery, and the presence of horses in the creek have the potential to disturb spawning coho and steelhead.
Proposed Project Actions
Proposed project components on the Redwood Creek Trail include decommissioning of 0.9 miles of trail in the floodplain and replacing this with 1.1 miles of new trail in the adjacent uplands, as well as construction of 1,300 linear feet of new trail. The project would remove two bridges, ten horse fords, four culverts, and two crib walls across channels, replace two bridges and install 11 new bridges, for 13 total bridges. Two of the bridges cross Redwood Creek, the other 11 cross tributaries and ephemeral drainages. Other new facilities include ten armored swale crossings, and a cascade channel rock structure at one of the culvert removals.
The proposed 1,300 linear foot extension of the Dias Ridge trail would connect the current terminus of the Dias Ridge Trail at the Golden Gate Dairy with the Redwood Creek Trail, as well connect to future improvements to the trail network in this area, per the GGNRA General Management Plan (2014). The Dias Ridge Trail, a part of the Bay Area Ridge Trail, is a multi-use trail, meaning that hikers, equestrians, and bicyclists use the trail. The existing trail gap results in visitors using the highway's narrow shoulder to go between the trails. There is little to no separation between motorists driving on this popular roadway and any pedestrians, equestrians, or bikers using the shoulder. To address this problem, an extension of Dias Ridge Trail is proposed to run parallel, but separate from, the east side of Highway 1, eliminating use of the shoulder by trail users.