Contract Description:
Our project goal is to restore healthy and harvestable salmonid populations through rehabilitation of stream habitat and restoration of ecological function in the riparian corridors of streams upstream of Grand Coulee Dam within the boundaries of the Colville Confederated Tribes reservation. Land use practices including residential and agricultural development, road building and logging have degraded habitat conditions and blocked upstream passage throughout many of the watersheds where historic tribal fishing once occurred. In order to identify and prioritize the appropriate fixes, we inventoried approximately 70 miles of stream habitat in the Upper Columbia Subbasin and over 80 miles in the Sanpoil Subbasin to help understand the magnitude of causes of that degradation. With that assessment in hand, we can form a plan to treat the root cause of the habitat degradation, rather than reacting to the symptoms which are observed at any one site. It is our intention to implement a restoration strategy that will restore and be consistent with the ecological processes described in the Upper Columbia Recovery Technical Team (UCRTT) Biological Strategy and the process-based principles outlined in Beechie et al. (2010). To accomplish this, our implementation strategy will follow the basic hierarchical strategy outlined in Roni et al. (2002). This approach begins with an assessment and inventory of the habitat conditions and degradations. Where habitat is degraded, we will seek first to reconnect isolated habitats then restore processes such as riparian condition and floodplain function before implementing actions that build temporary habitat. We have developed a habitat protection and restoration strategy using empirical observations of habitat conditions and the Ecosystem Diagnosis and Treatment (EDT) model that includes a multi-criteria prioritization strategy. We will begin working toward implementation of actions identified in the plan, as well as complete and maintain restoration identified in previous years.
Habitat restoration actions implemented in 2018 will include the status inventory and maintenance of approximately 16.6 miles of existing riparian fence, construction of 1.0 mile of new riparian fense, maintenance of riparian plantings/rehabilitation, and restoring fish passage through barrier replacement and removal.
Passage Barriers:
Locations of culverts and other stream crossings reservation wide were initially inventoried by Duck Creek Associates, Inc. under contract with the Confederated Colville Tribes (CCT) Environmental Trust Department. The stream crossings identified in this dataset that fell within the stream network used in the Ecosystem Diagnosis and Treatment (EDT) model were prioritized for further data collection in order to attribute assessment criteria provided in the Washington Department of Fish and Wildlife (WDFW) Fish Passage Barrier and Surface Water Diversion Screening Assessment and Prioritization Manual (WDFW 2009) and by the FishXing (Version 3) software program distributed by the United States Forest Service (USFS) Aquatic Organism Passage program. Assessments of passage potential from these methods, in conjunction with the anticipated amount of habitat upstream of each crossing, were used to calculate an index of linear stream habitat lost due to impassible barrier conditions. Index scores were binned into five priority groups. Stream crossings within each priority group were then qualitatively assessed for feasibility, immediate benefit to the target resource and location in relationship to natural barriers. The stream crossings selected for replacement during FY2018 was selected from a candidate pool as having the greatest habitat gain while occurring below natural barriers in the stream network without anthropogenic barriers downstream that require multiple years for partnership development and project planning.
We will replace 3 fish passage barriers in the Sanpoil Subbasin (Iron Creek; BIA Road 84) in 2018 to provide access to a total of 4.24 miles of habitat. Designs for bridges at each site were completed in 2017. The CCT will subcontarct culvert removal and bridge installation at each site in 2018.
In 2016, under this project, the CCT replaced a culverts in Strawberry Creek (BIA Road 62), North Nanamkin Creek (BIA Road 1003), and Thirtymile Creek (BIA Road 1045) that prohibited Redband Trout from accessing a combined 33.5 mi of spawning and rearing habitat. The culverts were each replaced with 10.67 m x 4.57 m (35 ft x 15 ft) concrete precast bridges. Bridge installation was completed in the fall. During a major flood event [possibly 200 year (2% probability)] in the spring of 2017, the Strawberry and North Nanamkin bridges were damaged. The footing on the east side of the Strawberry bridge was washed out and the east end of the bridge dropped approximately 1.2 m (4.0 ft) rendering it inoperable. An engineer from Cardno, a subcontractor of the CCT, visited the site in summer of 2017 and recommended that the bridge be replaced. The footing on the east side of the North Nanamkin bridge experienced some erosion putting the bridge at risk for further damage and eventual failure. The bridge remains in place, but an engineer from Cardno, a subcontractor of the CCT, visited the site in summer of 2017 and recommended that the bridge not be used in its current state. The bridge at Thirtymile Creek is still operational, but it has not been inspected by an engineer. Since it has the same footing design as the other two bridges there is concern that it is damaged and/or needs modifications to prevent scour.
In 2017, CCT hired a contract engineer to develop design plans for replacement/repairs/modifications of the bridges using standard industry practices. In 2018, the CCT will subcontract bridge replacement at Strawberry Creek and bridge footing repairs/modifications and scour protection at North Nanamkin and Thirtymile Creeks.
Fencing:
Over the last decade, fencing projects have been implemented to protect and restore riparian habitat along numerous streams in the Sanpoil River drainage. Successful protection and restoration of riparian habitat by fencing will only be successful if the fencing is regularly monitored and maintained. The project staff will monitor and maintain (repair) approximately 16.6 miles of existing riparian fencing along the following streams within the boundaries of the Colville Confederated Tribes reservation: Lost Creek (2.62 miles), Moses Creek (0.86 miles), Twentythreemile Creek (4.53 miles), North Nanamkin Creek (2.20 miles), Bridge Creek (0.52 miles), South Nanamkin Creek (0.93 miles), Capoose Creek (3.65 miles), and Moses Creek (1.31 miles). They will systematically inspect the entire length of fence; repairing it as they encounter damage. They will also revisit sections following storms.
Approximately 1.0 miles of new fence will be constructed along Lost Creek in order to exclude livestock from approximately 15.5 acres of riparian habitat which will allow for rehabilitation of the riparian corridor in this area.
Planting Maintenance:
Existing fencing units were also evaluated for response of the riparian community in 2017. Fencing units containing areas which have not responded to livestock exclusion were planted with riparian vegetation in 2015, 2016, and 2017. These areas include sections of the existing North Nanamkin (13.0 acres), South Nanamkin (8.0 acres), Lost (5.0 acres) and Twentythreemile Creek (8.0 acres) fencing units. In 2018, CCT staff will maintain the plantings at these sites by controlling (mowing and spraying) non-native vegetation and watering plantings during dry months.