Sitkum FS Road 2900 Crossing Designs – Phase 2

This project involved survey and complete designs and specifications for three non-fish bearing stream crossings at milepost 9.9, 10.6 and 11.5 along the Forest Service 2900 Road. The current crossings, which are undersized and in various stages of deterioration, pose a risk of failure that could lead to mass wasting events delivering large volumes of sediment into the Sitkum River. The Sitkum River provides vital spawning and rearing habitat for coho, Chinook, steelhead, and cutthroat trout, supports a unique run of summer steelhead, and delivers cold water to the South Fork Calawah River. Completion of these designs will help accelerate their eventual replacement through subsequent funding requests.

The goal of this project was to maintain water quality and fish habitat condition in the Sitkum River by producing contract ready designs and specifications to help prevent road failures at three sites along the FS 2900 Road. By having ready to implement designs, specifications and contract packages, the USFS and partner agencies can be poised to apply for funding for implementation of these pipes.

Replacing these pipes will benefit all species and lifestages present in the mainstem Sitkum River, and potentially for miles downstream. Target species present during the high winter flows that would most likely initiate road failure include coho and Chinook eggs, juvenile coho and steelhead, and adult steelhead. The designs were drawn to accommodate increased flows anticipated from climate change, allow for improved sediment and wood transport, and address current erosion issues at the sites. Completion of these construction-ready designs will accelerate replacement, which in-turn will reduce the risk of road-related mass-wasting events.