Limestone Creek Fish Passage


Shasta-Trinity National Forest

Project Location: This crossing is located on Road 33N47, a maintenance level 3 road that is valuable to the forest.

Link to the location of the remediated barrier in the CDFW Map Viewer (BIOS):

Passage Assessment Database ID: 707784
Project Description: The purpose of this project was to rehabilitate the Limestone Creek culvert crossing sufficiant to provide unrestricted passage for all aquatic species. The Limestone Creek crossing is a large earth fill with a 72-inch x 50 ft multi-plate steel culvert.  The road provides the administrative access into the area for fire suppression, resource protection and private property.  Rehabilitation of the crossing was necessary due to its age (50+ years) and undersize and it formed a barrier to fish and other aquatic species.
Pre-project conditions/barriers/challenges/background: The original crossing was designed to pass a 25 year storm event and was upgraded to pass 100-year storm flows. About 2,000 cubic yards of fill was removed from the existing cossing and placed in a stable waste area. The outlet had scoured a deep hole that, during low flows, allows the water level to be about 3 feet below the bottom of the pipe. The structure was a barrier to fish migration in Limestone Creek, a tributary to Big Creek near Hayfork, CA.
Project actions/deliverables: The 78-inch diameter corregated steel culvert was excavated and replaced with a 50-ft SPAN steel bridge.
Fish benefits/ecological value: The following known aquatic species now have unrestricted access through the crossing: coho salmon, steelhead, resident rainbow, Pacific lamprey, and Pacific giant salamanders. 
Other benefits: The new structure has restored capacity to pass flows and associated debris and no maintenance will be required in the future to remove lodge debris. In addition, the volume of fill material (~2,000 cubic yards) has been removed and no longer poses a threat to aquatic habitat downstream.

Amount of habitat made available as a result of project implementation: 2 miles.
Habitat quality and type characterization: Spawning and rearing habitat for steelhead and coho salmon.
Project cost: $199,705
Project start date: 2003
Project end date: 2005
Monitoring and evaluation:
Did the project make a difference, and if so, how?


Limestone Creek