The Imnaha Subbasin Plan (Ecovista and Nez Perce Tribe, 2004) identifies reconnection of existing functional habitats as a key strategy for restoration actions in the subbasin.  Three fish passage barriers in the Big Sheep Creek watershed have been identified: the Wallowa Valley Improvement Canal and Buhler diversions on Big Sheep Creek and the Lick Creek culvert.  GRMW replaced the Buhler diversion in 2011. Replacement of the Lick Creek culvert is part of the Lick Creek Aquatic Restoration Project (LCARP) that the Wallowa-Whitman NF is currently implementing.  Additional activities associated with LCARP include road reconstruction, campground improvements, OHV trail improvements, hardwood restoration, and closure of dispersed sites to restore and improve aquatic/riparian habitat in the Lick Creek Watershed.

The Lick Creek culvert is undersized, is a barrier to juvenile salmonids during low summer flows, and is structurally failing.  Lick Creek is prone to high stream temperatures downstream of the culvert while cool water refugia is present upstream of the culvert.  The culvert represents a risk to an estimated 1 mile of spawning and rearing habitat for all species present downstream of the culvert should the culvert fail.  The stream crossing is located in an area with a relatively broad floodplain and historically Lick Creek was likely a multi-thread channel through the project area.  The road prism interrupts floodplain connectivity through the project area.  Lick Creek provides high quality habitat for native salmonids both upstream and downstream of the stream crossing.  A large pool is located just downstream of the culvert.  This pool provides important holding habitat for adult spring Chinook salmon.

USFS has been monitoring the condition of the culvert since 2006 when cracks started to form in the concrete abutments on the upstream side of the culvert.  Since 2006, the condition of the culvert has continued to decline.  Failure of the culvert would likely result in degradation to an estimated 1 mile of spawning and rearing habitat for all species present below the culvert.  Since failure would likely occur during spring runoff there is a high likelihood of smothering of redds resulting in the death of salmonid embryos. The roadbed of FR3925-015 is built up where it crosses the floodplain of Lick Creek.  This has resulted in a disruption of floodplain connectivity through the project area.  An overflow culvert is present in the roadbed on the eastside of Lick Creek.  However, this culvert is too small to effectively handle a 100-year flood and resultant overbank flow.

Objectives for the Lick Creek Culvert Replacement Project are:

•   Restore access to spawning and rearing habitat above the culvert,
•   Restore access to cool water refugia present above the culvert for juvenile salmonids,
•   Remove risk to spawning and rearing habitat downstream of the culvert,
•   Restore floodplain connectivity through project area,
•   Retain/enhance habitat features that provide complex habitat for all life stages of native salmonids.

Replacing the culvert will remove a passage barrier to 2.5 miles of spawning and rearing habitat for SR steelhead; 1 mile of rearing habitat for juvenile SR spring Chinook salmon, 5 miles of spawning and rearing habitat for bull trout, and an estimated 2.5 miles of spawning and rearing habitat for Pacific lamprey.  Replacing the culvert will allow juvenile salmonids to access cool water refugia upstream of the stream crossing.  Replacing the culvert will also remove the risk to an estimated 1 mile of spawning and rearing habitat for all species present below the culvert should the culvert fail.  Replacing the culvert and installing floodplain relief culverts will restore floodplain connectivity through the project area.  The new stream channel through the project area will retain and enhance complex habitat features (i.e. pools and LWD) currently present.

The project will replace the culvert on the FR 3925-015 crossing with a bridge using the design developed through a 2015 OWEB Technical Assistance Grant.

Construction of the precast concrete bridge will involve removing the existing culvert, constructing the new channel, adjusting the road alignment to provide space for the fill for the abutments, and installing the proposed concrete bridge. The new bridge will be a 40-foot-span concrete bridge with concrete footings and abutments, and riprap banks.

Maintenance would occur as need by the USFS.

Monitoring Plan – The new bridge will be monitored annually for 3 years after replacement of the culvert to determine if the bridge and stream channel are functioning as designed.  This monitoring would occur after spring runoff and will be accomplished by the Forest engineering staff representative, District fish biologist and/or hydrologist.  The bridge will be inspected every two years by the Forest bridge inspector for structural integrity.  The FS and NPT will conduct effectiveness monitoring for five years above the stream crossing to determine it Chinook spawning or juvenile habitat is extended upstream of the stream crossing.