National. Park Service Mr. Chris. and Flathead PO Box 638 Kalispell, MT 59903

Transcription

1 QUARTZ CREEK FISH EXCLUSION BARRIER PROJECT CONCEPTUAL DESIGN ALTERNATIVES REPORT Submitted To: National Park Service Mr. Chris Downs, Fishery Biologist Science Center, Glacier National Park West Glacier, MT and Flathead Valley Chapter of Trout Unlimited PO Box 638 Kalispell, MT Submitted By: River Design Group, Inc Highway 93 South Whitefish, MT January 2009

2 TABLE OF CONTENTS Section Page 1.0 Introduction Purpose and Need Statement Study Area Description Physical Setting Fisheries Hydrology Existing Gabion Fish Exclusion Barrier Conceptual Design Alternatives Design Considerations Biological Constructability Sediment and Large Wood Inputs Alternatives Alternative 1 Retrofit Existing Barrier with Log Crib Alternative 2 Improve Existing Gabion Weir Alternative 3 Retrofit Existing Barrier with Log Crib and Culverts Discussion References 11 Appendix A Appendix B USGS Flood Frequency Analysis Results and Basin Delineation Drawing 1.0 Existing Weir Conditions and Hydraulics Drawing 2.0 Alternative 1 - Retrofit Existing Barrier with Log Crib Drawing 2.1 Alternative 2 - Improve Existing Gabion Weir Drawing 2.2 Alternative 3 - Retrofit Existing Barrier with Log Crib and Culverts

3 1 1.0 INTRODUCTION River Design Group, Inc. (RDG) was retained by the National Park Service (NPS), in conjunction with the United States Geological Survey Northern Rocky Mountain Science Center (NOROCK) and Flathead Valley Chapter of Trout Unlimited (TU), to evaluate an existing fish exclusion barrier located on Quartz Creek in the upper Quartz Lake Basin of Glacier National Park. Specifically, RDG was asked to evaluate the performance of the existing fish exclusion barrier and to develop conceptual design alternatives that would create a complete fish passage barrier and facilitate the effective removal or control of lake trout from Upper Quartz Lake. This report summarizes the results of the cursory assessment and provides three alternatives for retrofitting and/or replacing the existing fish exclusion barrier. 2.0 PURPOSE AND NEED STATEMENT In 2004, a partial fish exclusion barrier was constructed on Quartz Creek downstream of Middle Quartz Lake by NPS personnel and stakeholders. Subsequent to building the structure, in 2005, U.S. Fish and Wildlife Service (FWS) staff discovered lake trout in Quartz Lake upstream of the barrier (Fredenberg et al., 2007). No further attempts have been made to improve the partial barrier due to the uncertainty associated with control efforts once the lake was compromised. Prior to the discovery of lake trout, Quartz Lake was the largest bull trout lake in the Columbia River Basin with an intact native fish community uncompromised by nonnative species. Once non-native lake trout are established in mountain lakes similar to Quartz Lake, conversion of unique native bull trout ecosystems to non-native lake trout dominated systems is a common observation (Donald and Alger, 1993; Fredenberg, 2002). Numerous studies indicate that even when habitat conditions remain relatively unaltered, the transition to a fish community where non-native lake trout are the dominant piscivore may occur rapidly. The NPS and project partners are interested in evaluating options to create a complete fish passage barrier that would facilitate the effective removal or control of lake trout from upper Quartz Lake. 3.0 STUDY AREA DESCRIPTION 3.1 Physical Setting The project area is located approximately 7.4 miles northeast of Polebridge, Montana in the Upper Quartz Lake basin of Glacier National Park (Figure 3-1). The basin consists of two glacially carved lakes, Quartz Lake and Cerulean Lake. Combined, the two lakes have a surface area of approximately 920 acres and are tributary to Quartz Creek, a tributary to the North Fork of the Flathead River in the Columbia River basin. Quartz

4 2 Creek flows approximately 8.8 miles from the outlet of Lower Quartz Lake to the confluence with the North Fork Flathead River south of Polebridge, Montana. The existing fish exclusion barrier is located in a confined valley type characterized by steep valley walls, a narrow valley bottom, and coarse bed sediments derived from glacial and fluvial processes. Figure 3-1 includes a project vicinity map. Existing site conditions including the current fish exclusion structure are depicted in Figure Fisheries Native species in the Quartz Creek drainage include bull trout, a threatened species, westslope cutthroat trout, a Montana Species of Special Concern, mountain whitefish, longnose sucker, largescale sucker, sculpin, and redside shiner. The only known nonnative fish is lake trout, which were documented in Quartz Lake in Hydrology Hydrology in the Quartz Creek basin is snowmelt driven with peak flows typically occurring between April and June, although mid-winter rain-on-snow events can occur and produce floods of significant magnitude. For design and evaluation purposes, a flood frequency analysis was conducted for the Quartz Creek watershed. The analysis was performed based on methods outlined in the United States Geological Survey Water Resources Investigations Report Using Geographic Information System auto-delineation software, drainage area was determined to be 24.8 mi 2. Mean (weighted) annual precipitation is 75.7 inches, with a mean watershed elevation of 6,151 ft amsl (Figure A-1, Appendix A). Results were reported for three regression equations and methods including: 1) basin characteristics including watershed area and precipitation, 2) active channel width, and 3) bankfull channel width. Results are summarized in Table 3-1. Modeling output is included in Appendix A. Table 3-1. Flood frequency analysis results for the Upper Quartz Creek watershed (cfs). Recurrence Interval (yrs) Method 1 Method 2 Method 3 Average ,116 1, ,232 1, , ,646 2,166 1,373 1, ,250 2,956 1,946 2, ,150 4,127 2,787 3,355

5 3 Figure 3-1. Quartz Creek fish exclusion barrier project vicinity map.

6 4 Figure 3-2. The existing fish exclusion barrier on Quartz Creek downstream of Middle Quartz Lake in Glacier National Park. 3.4 Existing Fish Exclusion Barrier The existing fish exclusion barrier, as depicted in Figure 3-2, consists of 19 rock-filled gabion baskets measuring 2 ft x 2 ft x 6 ft in dimension. The structure is 68 ft in width and forms a 1.8 ft drop in the channel profile. General weir and stream characteristics are summarized in Table 3-2. A drawing of the existing weir condition is provided in Appendix A (see Drawing 1.0). Table 3-2. General characteristics of the existing fish exclusion barrier and site channel morphology. Barrier width (ft) 68 Maximum drop over weir crest (ft) 1.8 Maximum jump pool depth (ft) 2.5 Rosgen stream type B2 Average slope (%) 4-5 D 50 (mm) 300 Bankfull width (ft) The barrier creates a 1.8 ft drop in the stream profile and is hydraulically similar to a broad crested weir. To characterize existing hydraulic conditions, a compound weir equation was utilized and a stage-discharge table was developed to determine maximum velocities at the drop structure (Table 3-3). Based on communications with NPS, the 10-year peak flow was selected as the target flow rate for evaluating existing and proposed fish exclusion parameters. As summarized in Table 3-3, existing weir velocities range from 5.5 fps to 6.2 fps for the Q 2 and Q 10 flood discharges, respectively. Average flow depths range from 4.0 ft to 4.8 ft for modeled Q 2 and Q 10 flood discharges, respectively. Appendix A includes a diagram of the existing weir, existing condition hydraulic modeling results, and a cross-section profile of the gabion structure.

7 5 Table 3-3. The rating table for the existing weir including maximum velocities at the drop structure. Depth (ft) Discharge (cfs) Area (ft2) Velocity (fps) Top Width (ft) Approximate 2-year flood 2 Approximate 10-year flood Visual inspection and hydraulic modeling results of the existing barrier indicate that fish passage is likely possible during most flow stages. Predicted velocities and flow depths across the weir crest do not appear to completely limit upstream movement of lake trout. Additionally, during higher flows, passage is likely provided around, through and over the south wing of the gabion weir. Mobile flood debris (i.e. large wood and sticks) has collected on top of and around the gabions and recently deposited sediment was observed on the floodplain. 4.0 CONCEPTUAL DESIGN ALTERNATIVES The following section details structure and hydraulic design specifications for three fish exclusion barrier alternatives. The alternatives were developed in cooperation with NPS, TU and USGS and include: - Alternative 1 Retrofit existing barrier with log crib structure, - Alternative 2 Improve existing gabion weir, and - Alternative 3 Retrofit existing barrier with log crib structure and culverts. Conceptual design drawings for the three action alternatives are included in Appendix B. 4.1 Design Considerations Biological The traditional approach to evaluate fish swimming capabilities has been to divide swimming speeds of adult fish into various activity categories such as cruising, sustained (prolonged), and burst speed (Bell 1973, Dane 1978). The cruising speed is usually defined as the speed at which a fish can swim for an extended period of time without tiring. Sustained speed is the speed a fish can maintain for a prolonged period (typically several minutes or hours), eventually resulting in fatigue. Burst speed is

8 6 defined as the speed at which a fish can swim for just a very short time frame (one to several seconds) (USDA Department of Agriculture, 1990). Previous studies have documented cruising, sustained, and burst speed requirements for a variety of fish species including brown trout and trout. However, no published information is available for capabilities of lake trout. As a result, values from previous studies on other trout species were researched and used to evaluate barrier performance. The selected swimming speeds and references are summarized in Table 4-1. Table 4-1. Relative swimming speeds (fps) of average size adult fish. Specie Maximum Speed Cruising Speed Sustained Speed Burst Speed Trout Brown Trout RCT x WCT RCT Denil (1938); 2 Bell (1991); 3 Kreitmann (1933); 4 Region 1 MFWP, Personal Correspondence (2001) Constructability Due to the remote setting and restrictions on the use of combustible equipment in Glacier National Park, constructability is considered a major limiting factor with all proposed alternatives. Improvements to the existing structure, and any new structures, will be constructed using manual hand labor and tools. It is anticipated that a Bell helicopter or equivalent would be authorized by NPS to deliver project materials to the site (e.g. wood, culverts, other). Material staging areas would be developed at Bowman Lake and adjacent to the project area Sediment and Large Wood Inputs Due to the wild and natural setting of Quartz Creek, channel blockages in the form of ice and woody debris are likely. Abundant woody debris has been recruited to this section of Quartz Creek and plays an important role in maintaining channel stability, dissipating energy, and providing fish habitat. Given these conditions, a floating debris catcher may be required upstream of the barrier to minimize risk of damage to the structure. In particular, a debris catcher would be required under Alternative 3 to prevent clogging of the culverts. NPS and USGS will need to make a concerted effort to monitor the site and remove any high hazard trees and limbs that pose a direct threat to the function of the barrier. Sediment supply in the project area is not considered a major issue. Sediment derived from the upper watershed is attenuated in Upper Quartz Lake and Middle Quartz Lake. The channel bed is characterized by large, embedded substrate (e.g. cobble and boulders). Channel banks upstream and downstream of the weir are stable and characterized by low bank erodibility conditions.

9 7 4.2 Alternatives The following sections describe the proposed alternatives and preliminary hydraulic modeling results performed for each alternative Alternative 1 - Retrofit Existing Barrier with Log Crib Structure A conceptual design drawing for Alternative 1 is included as Drawing 2.0 in Appendix B. As shown, the existing gabion barrier would be retrofitted with a log crib structure filled with on-site native boulders. The structure is similar to techniques used for existing instream bridge supports on Quartz Creek and other streams in GNP. The timber crib structure would be positioned upstream of the existing gabions and span the full width of Quartz Creek. Individual cribs would measure 8 ft (length) x 6 ft (width) x 3 ft (height). Approximately 8 individual crib structures would be required to span the active channel. The wings of the structure would be anchored into the south floodplain / low terrace and north hillslope, respectively. A constricted flow opening measuring approximately 8 ft in width would be positioned in close proximity to the current barrier opening. The purpose of the constricted flow opening would be to increase low flow velocities. The existing staging pool would be eliminated downstream of the proposed structure by constructing a splash pad with gabions or other rock structures. Hydraulic modeling results for up to the 10 year recurrence interval discharge are summarized in Table 4-2. As noted, modeled mean channel velocities for Q 2 and Q 10 flood discharges would range from 9.2 fps to 10.2 fps. Figure 4-1. Example fish exclusion barrier built on Gilbert Creek, WY, a four percent, gravel bed stream channel. This approach utilizes techniques proposed for Alternative 1. The right photo includes a constructed splash apron that prevents staging pool development downstream of the weir. To increase the effectiveness of the barrier at low flows, a wire screen would be attached to the weir and extend downstream (cantilevered over the channel) to physically prevent fish passage through the constricted flow opening. The advantage of

10 8 replacing/augmenting the existing wire structure with a wood based structural design is largely related to structure longevity, which would be greatly increased with Alternative 1. Table 4-2. Stage-discharge table for Alternative 1 including maximum velocities. Depth (ft) Discharge (cfs) Area (ft 2 ) Velocity (ft/s) Top Width (ft) Approximate 2-year flood 2 Approximate 10-year flood Alternative 2 Improve Existing Gabion Weir A conceptual design drawing for Alternative 2 is included as Drawing 2.1 in Appendix B. As shown, the existing gabion barrier would be improved and expanded upon with additional rock-filled gabions. Existing baskets showing signs of deformation would be repaired and/or replaced. As shown in Drawing 2.1, approximately 8-12 additional gabions would be installed to further increase weir height and uniformity. This would improve the existing weir barrier by further cutting off the floodplain area that currently allows for potential fish passage during high flows. In addition, a splash apron or rock foundation would be installed downstream of the barrier to minimize jumping pool depths during all flows. As shown in Table 4-3, modeled mean channel velocities for Q 2 and Q 10 flood discharges would range from 9.7 fps to 11.9 fps. Table 4-3. Rating table for Alternative 2 including maximum velocities at the proposed barrier. Depth (ft) Discharge (cfs) Area (ft 2 ) Velocity (ft/s) Top Width (ft) Approximate 2-year flood 2 Approximate 10-year flood As described for Alternative 1, a wire screen would be attached to the weir and extend downstream (cantilevered over the channel) to physically prevent fish passage through the constricted flow opening. While the proposed improvements would increase the

11 9 function of the existing weir as a fish passage barrier, the primary disadvantage with this alternative is related to the use of wire, which has the tendency to deform and settle over time. Therefore, structure longevity would likely be decreased relative to Alternative 1 and Alternative 3 with this approach. As previously noted, a majority of the existing baskets are demonstrating some degree of deformation. Maintenance efforts and costs would likely be high with this alternative Alternative 3 - Retrofit Existing Barrier with Log Crib Structure and Culverts As a third alternative for fish exclusion, installation of multiple culverts in combination with upgrades to the barrier height are proposed. This approach and alternative would create both a major height barrier at all flows and a significant velocity barrier as shown on Drawing 2.2. Figure 4-2 demonstrates the general approach of this alternative, although multiple culverts would be utilized and nested in a timber crib structure supported, in part, by the existing gabion baskets. Table 4-4 summarizes the stagedischarge analysis for the proposed conditions. A splash apron would not be necessary for this option due to the height and velocity barriers that would result from the culverts. Figure 4-2. Example fish exclusion barrier constructed on Middle Fork Ponil Creek, New Mexico, utilizing techniques as proposed for Alternative 3. Table 4-4. The rating table for Alternative 3 including maximum culvert velocities. Headwater Elevation (ft) Discharge (cfs) Culvert Velocity (ft/s) Approximate 2-year flood; 2 Approximate 10-year flood; 3 Approximate 25-year flood

12 10 As summarized in Table 4-4, modeled mean channel velocities for Q 2 and Q 10 flood discharges would range from 18.2 fps to 25.2 fps. Velocities for up to the Q 25 are estimated to exceed 30 fps. A splash apron or modification to the downstream channel bed would not be necessary due to the velocity and height barriers that would be created under this alternative. 5.0 DISCUSSION Fish passage exclusion is best accomplished by creating vertical and velocity barriers that exceed the jumping and swimming capabilities of the target fish species, respectively. As published information on the swimming capabilities of lake trout is not available, values from previous studies on other trout species were researched and used to evaluate existing and proposed barrier hydraulic characteristics. Alternative 1 and Alternative 2 provide upgrades to the existing fish passage barrier by raising the height of the weir and by increasing water velocities. In addition, both alternatives create a more uniform crest height that further restricts the floodplain and potential for fish passage at high flows. However, for the 10-year peak flow, both of these alternatives only create velocities in the range of 10 fps to 12 fps. Based on maximum burst speeds for various species of trout, a velocity barrier may not be created and passage may still occur under these alternatives. Given the lack of documentation for lake trout swimming and jumping capabilities, the level of uncertainty cannot be accurately measured for Alternative 1 and Alternative 2. However, the functionality of the existing weir as a fish passage barrier would be significantly improved under both alternatives. Alternative 3 would create a complete barrier at all flows based on extremely high velocities that clearly exceed all fish swimming capabilities. The proposed concept would also create a significant vertical barrier to fish passage. Alternative 3 is the only alternative that would create a complete barrier from low flow up to a 25-year peak flow event. Alternative 3 would be more difficult and expensive to construct relative to Alternative 1 and Alternative 2. A more detailed engineering analysis of Alternative 3 would be required to ensure structural stability and hydraulic performance under a full range of flow conditions.

13 REFERENCES Bell, M., Fisheries Handbook of Engineering Requirements and Biological Criteria. Fish Passage Development and Evaluation Program, Army Corps of Engineers. Denil, G., The mechanics of riverine fish. Ann. Trav. Publ. Belge., 395 p. Donald, D.B. and D.J. Alger Geographic distribution, species displacement, and niche overlap for lake trout and bull trout in mountain lakes. Canadian Journal of Zoology 71: Fredenberg, W., M. Meeuwig, and C. Guy Action plan to conserve bull trout in Glacier National Park. U.S. Fish and Wildlife Service, Creston, Montana. Fredenberg, W Further evidence that lake trout displace bull trout in mountain lakes. Intermountain Journal of Science 8: Kreitmann, M Les barrages et al circulation des poissoms. Bull. Soc. Centr. D Agriculture et de Peche. 40. United States Geological Survey. February Methods for Estimating Flood Frequency in Montana Based on Data through Water year Water-Resources Investigations Report Helena, Montana.

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19 APPENDIX B

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