Tule Creek Fish Passage


Shasta-Trinity National Forest


Project Location: This crossing is located on Road 31N31, a maintenance level 3 road that is valuable to the Shasta-Trinity National Forest. Tule Creek is a tributary to Hayfork Creek, Trinity River Basin, Shasta-Trinity National Forest, in Northern California

Link to the location of the remediated barrier in the CDFW Map Viewer (BIOS): https://map.dfg.ca.gov/bios/?al=ds69&col=pad_id&val=707854.

Passage Assessment Database ID: 707854


Project Description:  The purpose of this project was to rehabilitate the Tule Creek culvert crossing sufficient to provide unrestricted passage for all aquatic species. The Tule Creek crossing is a large earth fill with a 72-inch x 115 ft multi-plate steel culvert. The road provides the administrative access into the area for fire suppression, resource protection and private property.


Pre-project conditions/barriers/challenges/background: Rehabilitation of the crossing was necessary because of its age (50+ years), it was undersized, and it formed a barrier to fish and other aquatic species, such as amphibians. The restriction and gradient of the old culvert increased the water velocity to the point that fish and other aquatic species were unable to travel upstream.

  • 6 ft (1.8 m) diameter x 115 ft (35.1 m) long multi-plate steel culvert (circa 1950’s)

  • Aggraded channel at inlet likely caused by frequent backwatering from undersized culvert
  • Grouted undermined outlet apron perched as much as 3 ft (0.9 m) above large scour pool

Project actions/deliverables: The 72-inch diameter corregated steel culvert was excavated and replaTule Creek culvertced with a 64-ft SPAN concrete bridge.  The crossing was originally designed to pass a 25-year storm event and upgraded to pass 100-year storm flows. About 2,000 cubic yards of fill were 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 Tule Creek, a tributary to Hayfork Creek near Hayfork, CA.


Fish benefits/ecological value (i.e., species affected): The following fish species will now have unrestricted access through the crossing: steelhead, resident rainbow trout, speckled dace, Pacific lamprey, Pacific Giant salamanders, foothill yellow-legged frog.

Tule creek after culvert removal

Other benefits (flood control, utilities, wildlife connectivity, etc.):

  • 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. About 2,000 yards of fill material has been removed and no longer poses a threat to aquatic habitat downstream. 
  • Reduce risk of crossing failure and delivery of fine sediment to downstream critical habitat for coho salmon and steelhead trout

  • Provide access to thermal refugia for rainbow trout during mainstem summer low flows

Amount of habitat made available as a result of project implementation: About 2 miles


Challenges/lessons learned:

  • Desire to prevent scour and incision of large alluvial deposit upstream of culvert
  • Used large volume of rip rap to prevent scour and channel incision of channel under bridge
  • Construction extended past October 15th into wet weather season
  • Dewatering worksite became more difficult as project extended into fall and stream baseflow increased
  • Difficult to isolate worksite from stream channel and control downstream turbidity during in-channel work


Project partners: Shasta-Trinity National Forest and KLM Construction Ltd.


Project cost: Planning and permitting: $4,000; Construction/materials: $280,000; Inspection: $10,000. Total: $294,000


Funding sources: US Forest Service


Project end date: July 2005

Monitoring and evaluation:


Initial performance standards or goals: Remove an aging, undersized road crossing to improve access to spawning and rearing upstream fish habitat and connectivity for amphibians.


Did the project make a difference, and if so, how? Instream turbidity and suspended sediment data collected during implementation show that construction activities measurably increased instream fine sediment. Downstream measurements show that levels returned to background within ¼ mile of the site. No turbidity or suspended sediment increases were measured three miles below the site during project activities. Measurable incision of the stored sediment upstream of the road-stream crossing occurred, but was considered minor compared to the amount predicted to mobilize without grade control structures.