Habitat Assessment

 

Goals and objectives of Habitat Assessment Project

Friends of the Teton River (FTR) surveyed the Upper Teton River during the summers of 2002, 2003 and 2004 as a part of the Habitat Assessment Project (HAP). HAP is designed to assess and improve aquatic habitat conditions. The project consists of a visual channel assessment survey and a site specific stream survey. A multi-disciplinary team visually surveyed the Upper Teton River from the confluence of Fox Creek to the Highway 33 Bridge. The team consisted of representatives from Idaho Department of Fish and Game, U.S. Army Corps of Engineers, InterMountain Aquatics, Teton Regional Land Trust, Natural Resources Conservation Service, Idaho State University, local residents and independent consultants. Following the visual assessment, the team met to discuss findings from the visual survey and to prioritize further actions. In order for FTR to formulate a restoration plan for the Upper Teton River, it was decided that a geomorphic survey needed to be completed and historic records examined.
FTR used the Habitat Assessment Stream Survey (HASS) to survey the Upper Teton River. Using HASS, FTR collected detailed information on channel geomorphology, fish habitat, riparian vegetation and bank stability. Site boundaries were determined by examining site characteristics, upstream controls and potential effects from downstream conditions. At each site, five equally distributed, monumented x-sections were installed. A total station or automatic level was used to collect detailed x-section profiles including bankfull location, bank shape, water surface elevation and streambed elevations. Gradients for each site were surveyed in one day using water surface elevation. Fish habitats were characterized using a modified version of R1/R4 Fish Habitat Survey criteria. The average percentage of macrophytes was determined along two x-sections using a grid box. Information collected on bank conditions included: percent bank erosion; bank material type; predominate vegetative overstory and understory; percent overhanging vegetation; willow distribution and percent undercut banks. Notes were recorded concerning substrates, fish observations and unique site features. Photos were taken of each site, up stream and down stream of each site and of the banks at each x-section. Sketches were made for each site.


Actual Accomplishments

The Upper Teton River was separated into to three study sections: Section 1 was surveyed in 2003; Section 2 was surveyed in 2002; and Section 3 was surveyed in 2004 (Map and Data).
Section 1, surveyed in 2003, extends from the confluence of Fox Creek to South Bates Bridge. The section is typically straight, flat, wide and shallow, with silt substrate and nearly 100% macrophyte coverage. Numerous natural and constructed islands, sloughs, backwaters and side channels are located within the section. The low banks are predominately lined with reed canary grass. Patches of willows are located throughout the section. It appears that willows were removed for grazing especially along the east bank. Through the visual assessment, FTR prioritized 10 survey sites. Sites included reaches with recent deposition, man made islands, depositional islands, side channels, reaches that appear static since 1960 and reaches at the confluence of major tributaries. Survey sites were approximately 600 feet in length adding up to a total of 6,000 feet of surveyed stream.
Section 2, surveyed in 2002, extends from South Bates Bridge to the Rainey Fish and Game Access. The section is fairly straight, wide and flat in the beginning and becomes more sinuous and braided downstream. Substrates consist of small gravel, silt, sand and clay. Macrophytes cover over half of the channel. Predominate understory consists of grasses and sedges. Predominant overstory consists of willow. The banks consist of clay and easily eroded silt and loam. The channel displays both spring-dominated and runoff-dominated characteristics depending on spatial and temporal conditions. Through the visual assessment, FTR prioritized 11 survey sites. Surveyed sites included 6 restoration sites, 2 recovery sites and 3 reference sites. The sites averaged about 490 feet in length adding up to a total of 5390 feet of stream surveyed.
Section 3, surveyed in 2004, extends from Rainey Fish and Game Access to the Highway 33 Bridge. The section is low gradient, sinuous and braided, with substrates consisting of silt, moderately embedded gravel with some clay and cobble. Numerous sloughs, backwaters and side channels are located within the section. Fish habitat types include mid-channel scour pools, lateral scour pools, glides and low gradient riffles. The low banks are predominately lined with reed canary grass. Willows are located throughout the site. It appears that along many areas, willows were removed for grazing and to conserve water. Through the visual assessment, FTR prioritized 13 survey sites. Sites included reference sites and restoration sites. The survey sites averaged 387 feet in length, adding up to a total of 5,031 feet of surveyed stream.

Other Pertinent Information

Data analysis was performed for each x-section, each site and for each section. The x-sections were analyzed to determine bankfull width, maximum depth, average depth, W/D ratios and gradient. Bank conditions, willow distribution, substrates, fish habitat types and fish observed were analyzed for each site. Macrophyte data was analyzed to determine the percentage of macrophyte cover. Soils adjacent to sites and along the sections were inventoried.
For Section 1, the W/D ratios ranged from 57.44 to 168.11 and had a mean of 108.83. Gradient ranged from .00022 to .00047 and had a mean of .00034. Site substrates consisted of 6-18 inches of silt with embedded gravels underneath. Macrophytes covered 65.81% to 93.67% and had a mean coverage of 80.97%. All sites were a low gradient glide habitat type. Numerous fry were observed in the shallow and backwater areas. Few adult trout were observed.
For Section 2, the W/D ratios ranged from 12.99 to 107.59 and had a mean of 38.55. The gradient ranged from .00013 to .00267 and had a mean of .00078. Sediment consisted of silt, sand, clay, small gravel and embedded small gravel. Macrophyte coverage averaged 46.59% over all the sites. A variety of fish habitat types characterized Section 2. Most of the sites had at least one lateral or mid-channel scour pool and a glide. Several sites had low gradient riffles. Numerous fry and juveniles were observed in the shallow and backwater areas of all sites. Adults were observed at some sites.
For Section 3, the W/D ratios ranged from 17.26 to 83.32 and had a mean of 35.24. The gradient ranged from .00023 to .00438 and had a mean of .00124. The section was predominately covered in moderately embedded, mixed gravels and silt. Macrophytes covered 2.5% to 67.45% of the channel and had a mean coverage of 28.92%. A variety of fish habitat types characterized Section 3. Most of the sites had at least one lateral or mid-channel scour pool and a glide. Four sites had low gradient riffles. Numerous fry and juveniles were observed in the shallow and backwater areas of all sites. Adults were observed at some sites.