Annadel State Park Erosion Control: Geary Ranch Road to Trail Conversion

Abstract:

This project will restore approximately two miles of extremely steep, degraded fire road where severe environmental damage is occurring in the form of accelerated erosion, creek sedimentation and deep down cutting, and replace it with a properly designed trail. This work will serve both the purpose of providing sustainable, environmentally-friendly trails, along with enhancing public access in a prime natural area that experiences very heavy public visitation.  The main project partner, The Sonoma Ecology Center will deliver pre-treatment sedimentation evaluation and monitor project improvements through water-quality assessment, photomonitoring, and geomorphic evaluation.  State Parks will conduct and oversee much of the actual construction with cooperation and assistance from the Sonoma County Trails Council and the Bay Area Ridge Trail Council.    

Purpose: This project is located at Annadel State Park, Sonoma County, between Highway 12 in the Sonoma Valley and Highway 101. Annadel is the major landbase within the Sonoma Valley where over 300,000 trails users recreate annually. The project is located along a major Sonoma County landmark, Bennett Mountain, which is visible from both Santa Rosa and Highways 12 and 101. Purpose: The project will convert a very degraded, unsafe road to trail. The purpose of converting the road to trail is to correct the severe erosion currently occurring along the length of the road, thus improving water quality downstream. Unsurfaced dirt roads on shallow soils on hillsides are a large, chronic source of sediment pollution. The severely degraded Geary Ranch road will be removed and the natural topography and drainage restored to the site. We will use techniques established in previous projects to re-contour, and revegetate the site. A new replacement trail will be realigned on contours (a curvilinear trail alignment), designed to not interrupt overland sheet flow and hydrologic prosesses, and will link with other trails in the park. It is important to provide the public with environmentally-sound trails into natural areas, in order to help foster in those people a sense of understanding and stewardship of natural areas. Need: Sonoma County's land-use practices over time have adversely affected land cover, stream stability and geometry, the production and transport of sediment, and water and habitat quality. These changes may have contributed to declines in species such as threatened steelhead trout and other affected rare species. DPR must strike the delicate balance between public access and resource protection. As visitation increases, additional limitations could be placed on access to the top of Bennett Mountain. If insufficient funds are obtained, then the road could be fully removed without providing the public enhancement of a new public trail in this location. This restoration action would create political havoc for the landowner, California State Parks, whose Mission requires public recreational needs to be considered. The Geary Ranch acquisition occurred in l997. Since that acquisition, sufficient land base is now available to install a well-designed and constructed trail which will include views of both the greater Bay Area and the Sonoma Valley. This new trail will likely be dedicated a connector of the Bay Area Ridge Trail due to the views that this link will provide. Goals and Objectives: The Geary Ranch Road has a terrible alignment that either goes straight up the fall line of the landform or straight up the ridgeline. It is currently disrupting and capturing the overland sheet flow associated with the hillside. This captured flow has developed gullies several feet deep into the road bed at some locations and has eroded down to bedrock at others. Sediment-laden water currently conveys down the entire degraded roadbed. One of the major goals of this project is to eliminate that sediment source, thus improving water quality in the area. This is a high visibility project that is located in the upper watershed of a State Park. This project continues several phases of major watershed restoration within Annadel State Park. This effort gives DPR the opportunity to continue to showcase its landform and roadbed reshaping to the public, consequently educating the public about watershed function and restoration. Critical Impacts: If this project does not occur, the degraded road (which is closed to the public) will continue to damage the landscape. The only remediation to the excessive sedimentation production is the full removal of the road. Additionally, the public will continue to trespass into this location over private property, and continue with off-trail blazing to satisify public access needs to this prisitine viewpoint. Multiple visitor-created trails will result in additional landscape scarring, habitat fragmentation and erosion. The new replacement trail proposed as part of this project will help to correct those otherwise ongoing impacts to natural resources. The current road is unavailable to the public except through private property or visitor-created trails: Both of which are unlawful for use and unattractive to most visitors as a choice of trails to use within the park. This project will increase visitation, improve the visitor experience and provide greatly enhanced recreational opportunities. Bennett Mountain will be a highly used destination within the park.

Keywords:

Watersed Management Strategies:

Functional Areas: