Grande Ronde River Fish Habitat Restoration Project
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Case Study 5 Grande Ronde River Fish Habitat Restoration Project Project Overview The Grande Ronde River Fish Habitat Restoration Project was implemented in 1995 on the Wallowa-Whitman National Forest, La Grande Ranger District, near La Grande, Oregon (figure 1). The project is located in a 3.5-mile reach of the Upper Grande Ronde River (UGRR), a tributary of the Columbia River. The UGRR watershed is located in Northeastern Oregon within the Blue Mountain Subprovince of the Columbia River Plateau Physiographic Province. This subprovince is characterized by broad rolling upland surfaces to the north and complex mountains and dissected volcanic plateaus to the south. A variety of rock types exist in the Upper Grande Ronde area with the dominant type being Columbia River Basalt. This basalt flowed through the fissures and dikes, flooding the area with many pulses forming a thick sequence of basalt. This area experiences a relatively cool, moist climate with a short growing season and little-to-no summer precipitation. Annual precipitation averages 20 inches per year and ranges from 15 to 30 inches, much of it falling as winter snow. Temperatures range from an average summer high of 80 degrees Fahrenheit to an average winter low of 17 degrees Fahrenheit. Summer temperatures fluctuate widely, with hot days and cold nights. Portions of the drainage are located within summer lightning corridors and may experience localized brief, torrential rain events. At higher elevations, frost can occur almost any night of the year. Winter temperatures remain low for long periods, with considerable snow accumulation. Various past management activities of streams and riparian areas in the Pacific Northwest have reduced the interaction of large woody debris (LWD) with streams, simplifying and thus degrading aquatic habitat for threatened populations of anadromous fish (Keim et al. 1999). In the UGRR, timber was removed from the riparian area along the mainstem Grande Ronde River and tributaries for making railroad grades and Grande Ronde River Fish Habitat Restoration Project building roads. Because trees in and near valley bottoms were easier to reach and transport than trees located further upslope, fewer trees were available for recruitment as LWD to the stream channel. Mining activities in the UGRR took cobble and gravel from the stream channel and deposited it in large tailing piles on the banks, destroying existing vegetation and reducing chances for future vegetative growth (UGRR Watershed Analysis 1995). In addition, installation of roads 5100 and 5125 constricted lateral movement of the stream channel, reduced effective floodplain area, and restricted interactions between the stream and riparian area. Splash dams used around the turn of the century for transporting logs resulted in high 3—57 Developing Monitoring Plans— Chapter 3 stream energy, thereby removing much-needed sediment-retaining and habitat-forming structure. Moreover, in the 1970s, much of the LWD in the UGRR and tributaries was removed because it was viewed as an unsightly barrier to fish migration (Braudrick and Grant 2000). LWD is important in forming morphology of stream channels and aquatic habitat, both locally and at the reach scale in streams within forested watersheds (Wing et al.1999). LWD influences stream morphology by dissipating the hydraulic power of the stream (Beschta and Platts 1987) to form pools (Lisle 1986; Montgomery et al.1995) storing sediment in channels and creating gravel bars (Bilby and Ward 1989; Smith et al. 1993b; Nakamura and Swanson 1993). Physical habitat stream surveys of the UGRR conducted in the 1940s and repeated in the 1990s revealed that pool habitat had reduced 78 percent (McIntosh 1992). Pool frequencies for all the reaches in the UGRR watershed are below 7 pools per mile, which is considered very poor. The width-to-depth ratio for all reaches in the UGRR watershed are greater than 15 (>10 considered desirable). Pieces of woody debris per stream mile are less than 40 for (desired future condition) all reaches. Cobble embeddedness has also been shown to be greater than 50 percent, which can potentially be detrimental to spawning salmonids. These conditions identified a need to reestablish the aquatic habitat needed to protect and maintain the three federally listed fish species that occupy the UGRR. The Grande Ronde River Fish Habitat Restoration Project proposed to create pool habitat, decrease channel widths, and provide fish hiding cover by placing 92 whole conifer trees with root wads and crowns with no permanent anchoring devices (such as cable or rebar). To determine the level of change stream channel surveys, we used photo points and mapped tree locations to measure whether the project reach was meeting the riparian management objectives (RMOs) described in PACFISH (USDA and USDI 1994). The RMOs are described in terms of habitat features. Grande Ronde River Fish Habitat Restoration Project The objectives for the Upper Grand Ronde River (UGGR) are 26 pools permile, greater than 20 pieces of large woody material (LWM) (greater than12 inches diameter breast height and greater than 35 feet in length) per mile, greater than 80-percent stable streambanks, and width-to-depth ratio of less than 10. We monitored pool frequency, amount of LWM, streambank stability, and width-to-depth ratios for this project (table 1). We monitored project effectiveness by asking and answering the following question: “Did the addition of whole trees with root wads, crowns, and no anchoring in the river basin increase the channel and habitat complexity for anadromous fish?” 3—58 Case Study 5 Grande Ronde River Fish Habitat Restoration Project Figure 1. General location of the Wallowa-Whitman National Forest, La Grande Ranger District Grande Ronde River Fish Habitat Restoration Project. 3—59 Developing Monitoring Plans— Chapter 3 Project Methods, Design, and Monitoring The La Grande Ranger District of the Wallowa-Whitman National Forest initiated monitoring in 1995 to determine effectiveness of the structures in enhancing channel morphology and assessing vegetative response over time. To conduct stream surveys, we used a USDA Forest Service, Pacific Northwest Region (Region 6) Level III stream inventory methodology developed from modifying Hankin and Reeves (1988) protocol. To measure changes in channel and habitat conditions, we surveyed the entire project area before project implementation in 1995, immediately after project completion in 1996, and again in 2003 (table 2). Immediately after the project began, we tagged all the down LWM meeting the large criteria (greater than 12 inches diameter breast height and greater than 35 feet in length) with metallic tags and mapped them on aerial photo overlays. To measure the movement and stability of all tagged and recruited trees, we recorded tree locations annually for 5 years—using a string box after project implementation—and again in 2003. To visually assess vegetative response, we established monumented photo points at 10 sites throughout the project area. We have repeated the photo points annually since 1995. The criteria for determining the success of this project were changes in stream channel morphology and habitat compared to the RMOs set by PACFISH (USDA and USDI 1994). Table 1 displays each parameter monitored in the project area, the methodology used, and the monitoring results relative to the RMO that the parameter was intended to meet. Table 1. Channel and habitat parameters monitored, methodology used, and project success criteria. Parameter Methodology Success Criteria Large woody debris Direct measurements No net loss of LWD stability and photos in project area Grande Ronde River Fish Habitat Restoration Project Large Woody Debris R6 Level II & III > 20 pieces/mile of (pieces per mile) Steam Habitat Survey LWD (>12”:>35’) Pool frequency (pool- R6 Level II & III RMO of 26 pools to-mile, pool depth) Steam Habitat Survey per mile Width-to-depth ratio R6 Level II & III RMO width/depth Steam Habitat Survey ratio of <10 Bank cover R6 Level II & III RMO of >80% (stability) % Steam Habitat Survey stable banks 3—60 Case Study 5 We used the following assumptions for this project: 1. Increased habitat complexity will increase rearing capability and ultimately increase smolt production. 2. Increased amounts of LWD will create more complex habitat and increase floodplain interaction with the channel. 3. Increased riparian vegetation will reduce width-to-depth ratios. 4. LWD added to the channel will stabilize in the stream system. The LWD will trap sediment that will increase the level of the stream bed and raise the water table, and will result in an increase in riparian type vegetation that will help to stabilize the streambanks. The data limitations in this project are observer bias during collection of stream survey data and the use of a string box for measuring the movement of LWD. The string box is not an acceptable measuring tool for channel unit length for several reasons. First, the string assumes straight-line positions between points and assures that each observer will walk a different line. Second, if the string is not kept taut, the current can easily pull out an unknown amount of string. Third, the string can stretch in the rain. All of these problems can cause inaccurate measurements of tree locations. A more accurate yet resource-demanding method would be using a global positioning system (GPS) and digitizing or inserting the tree locations into a geographical information system (GIS) layer. Monitoring Results and Interpretation We achieved the main objective—adding LWM to increase habitat complexity to the level that the individual stream attributes met RMOs— with the exception of width-to-depth ratios (tables 2 and 3). The width- to-depth ratio for the UGRR in the project reach is close to equilibrium and should not further increase, because of the restrictions to the channel imposed by the 5100 and 5125 roads. The reach is also a Rosgen B-type channel, is moderately confined, and has a natural width-to-depth ratio Grande Ronde River Fish Habitat Restoration Project of greater than 12.