Potential impacts to fish habitat generally occur in relation to water quality and water quantity as these characteristics directly affect the ability of fish habitat to sustain fish. The analysis below is structured by these headings to identify management that would result in impacts to these characteristics of aquatic habitats. Section 4.1.4 Water includes additional detail on potential impacts to water quality and quantity from implementing alternatives. Section 4.4.3 Vegetation - Riparian/Wetland Resources describes impacts to riparian/wetland habitat that may also affect fish habitat.
The principle impacts to fish habitat result from management actions that affect water quality and quantity. These impacts would be similar under all alternatives, but the degree and intensity of impacts vary by alternative based on restrictions, allocations, projected activity, and other management, as described for each alternative. See Impacts Common to All Alternatives in Section 4.1.4 Water for a detailed analysis of impacts to surface water quality and quantity. See Section 4.1.3 Soils and Appendix V for a more detailed description of the methods used to predict the erosion rates that appear below.
Under all alternatives, fish habitat would be affected by management actions that alter water quality through sedimentation and related degradation from surface-disturbing activities, water temperature changes, water chemistry changes, and riparian area management and restoration.
Increased sediment in fish habitat (streams, rivers, and reservoirs) decreases the potential for fish to naturally reproduce, fills in pools, leads to channel degradation, decreases light penetration and productivity, alters fish community composition, and increases stream temperature. Activities that increase surface runoff can erode stream banks, altering riparian habitat and reducing the quality of in stream habitat for fish. Changes in aquatic habitats could lead fish to alter their uses of the stream, moving to different areas for feeding and spawning, or eliminate their ability to survive, depending on habitat conditions.
As noted in Section 4.1.4 Water, concentrated grazing by livestock, wild horses, and wildlife may contribute to soil compaction and damage to the vegetative cover and soil crust, thus increasing surface water runoff, erosion, and sedimentation. Fishbearing streams do not flow through the McCullough Peaks or Fifteenmile HMAs under any alternative, so adverse impacts from wild horses would be minimal under all alternatives.
Water quantity is primarily affected by activities that alter water runoff and water discharge. In areas with little vegetation, less rainfall infiltrates the soil and therefore more runoff may reach stream systems. Greater runoff can cause accelerated erosion and increased sediment loading in streams and rivers. Impervious surfaces and compacted soils may result in higher volumes of water reaching stream systems in shorter time periods, thus increasing flow rate, flood frequency, and erosion. Stream bank disturbance could impact fish habitat by creating bank instability, which could alter flow and destroy pool-riffle formations needed for fish survival.
Produced water from conventional and CBNG wells is sometimes discharged to the surface, contributing additional flows into the surface water system. These discharges can alter the timing, location, and volume of local streamflow patterns. In the Planning Area, produced water discharges, although overall beneficial to stream habitat, result in both beneficial and adverse impacts. Particularly during periods of low flow and spawning, aquatic species may be affected by the amount of produced water discharged to the surface. Produced water discharge can increase flow rates and erosion in stream channels, contributing to sedimentation. BLM policies and BMPs, required as COA, minimize and mitigate, to the extent possible, erosion from produced water surface discharge. Produced water is also generally hotter than naturally occurring surface water, and contains dissolved compounds that can be toxic to fish. Downstream from the discharge point, cooled produced water that has released some of its dissolved chemical components can have a beneficial impact on stream habitat.
Surface disturbance results in adverse impacts to fish habitat by increasing soil erosion and sedimentation that degrades water quality. Alternative A is anticipated to have short-term (136,415 acres) and long-term (15,710 acres) surface disturbance over the life of the plan (Table 4-1) causing erosion rates of 568,166 and 25,176 tons per year, respectively, that would contribute to sedimentation. Surface-disturbing activities are prohibited within 500 feet of surface water or riparian/wetland areas to minimize potential water quality impacts. Relative to the other alternatives, Alternative A includes the second fewest restrictions on activities that remove vegetation and compact soils, resulting in more storm water runoff entering streams.
Under Alternative A, 4,033,195 acres are available for locatable mineral entry, 4,052,688 acres are open for oil and gas leasing, and 3,975,695 acres are open to mineral materials disposal. Alternative A closes areas encompassing 46 miles of fishbearing streams to locatable mineral entry (Table 4-9). There would be some oil and gas development in areas that drain into fishbearing streams, although there are 35 miles of fishbearing streams in areas closed to oil and gas development under Alternative A (Table 4-9). This alternative is anticipated to result in the development of 1,130 new federal wells, and produced water may impact fish habitat by changing flow regimes and contributing to sedimentation.
Under Alternative A, the BLM limits motorized vehicle use to existing roads and trails on 2,332,355 acres. Motorized vehicle use is likely to contribute to sedimentation in areas where existing roads and trails are in close proximity to, or cross, rivers and streams. Allowing off-road motorized vehicle use for big game retrieval and dispersed campsite access in areas with limited travel designations may result in new roads and trails that would impact fish where they cross rivers or streams or increase sedimentation. Alternative A closes 59,192 acres to motorized vehicle use and limits it to designated roads and trails in The Rivers SRMA and in areas with fragile soils, reducing adverse impacts from erosion and sedimentation.
Recreation sites (e.g., campgrounds, day use areas) are developed as demand warrants under Alternative A. Campground and recreational facility development in riparian/wetland areas can degrade water quality by removing vegetation and increasing erosion and sedimentation. The increased angler access provided by recreation facilities near water courses can also directly impact fish habitat (e.g., trampling of banks and stream bottoms, accidental fuel/chemical spills). Alternative A provides for and emphasizes opportunities for recreational access to rivers and streams, potentially causing adverse impacts to fish habitat.
Forest management under Alternative A allows for the third highest degree of vegetative treatment, including clear cuts, precommercial thinning, woodland treatments in aspen and juniper stands, and prescribed fire, that could contribute to soil disturbance and sedimentation in streams and rivers in the short term. However, Alternative A uses treatments and timber harvests to improve forest health; most of these treatments may decrease the probability of stand replacing wildfires that can cause erosion and sedimentation, and therefore benefit fisheries in the long term.
Special designations under Alternative A that protect riparian habitat and water quality by restricting surface-disturbing activities include the Carter Mountain, Five Springs Falls, and Upper Owl Creek ACECs, in total encompassing 29 miles of fishbearing streams (Table 4-9). Under this alternative, water impoundments, major diversions, or hydroelectric power facilities are prohibited on all WSR eligible waterway segments. These segments are closed to mineral materials disposal; however, many remain open to mineral leasing and the associated adverse impacts to water quality and quantity. This management in special designations would mostly result in beneficial impacts to fish habitat; however, there also may be an adverse impact because NWSRS management under Alternative A may limit native species restoration activities.
Alternative A uses treatments and timber harvests to improve forest health; most of these treatments may decrease the probability of stand replacing wildfires that can cause erosion and sedimentation, and result in beneficial impacts to fish habitat in the long term. Riparian/wetland areas are managed to meet or make progress towards meeting PFC under Alternative A, providing long-term benefits to water quality. The prohibition of surface-disturbing activities within 500 feet of riparian/wetland areas provides beneficial impacts to fish habitat by reducing sedimentation into streams and reducing stream bank degradation. Alternative A does not fence wetlands or riparian areas to meet resource objectives, leaving these areas vulnerable to potential impacts from other resource uses or activities and potential degradation of fish habitat.
Direct beneficial impacts to fish as a result of proactive management under Alternative A result from encouraging reservoir design to establish minimum pools sufficient to maintain viable fisheries, intensively managing intermittent streams and restoring streams and fisheries habitat on a case-by-case basis, and managing fisheries habitat to improve and enhance its value (e.g., vegetation planting and installing sediment and erosion control structures).
Impacts on fish habitat from surface disturbance would be similar to those described under Alternative A, although to a lesser degree due to decreased surface disturbance. Management under Alternative B would result in less surface disturbance over the short term (73,919 acres) and long term (10,882 acres) resulting in approximately 45 percent and 31 percent less erosion than Alternative A in the short and long term, respectively. Compared to Alternative A, fewer opportunities exist for surface-disturbing activities, including oil and gas and ROW development in areas that contain fishbearing streams (Table 4-9). More areas are designated as having NSO and CSU restrictions along perennial streams, riparian areas, and waterbodies under this alternative. Alternative B prohibits surface-disturbing activities and surface occupancy within ¼ mile of Class 1 and 2 streams, providing the greatest beneficial impact to water quality and fish habitat compared to the other alternatives. Alternative B includes the most restrictions on activities that remove vegetation and compact soils, resulting in the least adverse impacts to fish habitat due to increased runoff.
Minerals development under Alternative B would result in the least adverse impact to fish habitat from sedimentation and other potential impacts to water quality. This alternative closes the greatest area to locatable minerals and oil and gas development containing fishbearing streams (80 and 122 miles, respectively). Alternative B prohibits new surface discharge of produced water, which would limit beneficial impacts to stream habitat, but also potential adverse impacts from altered flow regimes and water chemical properties.
With the most area closed, the most area limited to designated roads and trails, and the least area limited to existing roads and trails, Alternative B would result in the least adverse impacts from motorized vehicle use to water quality, compared to the other alternatives. Prohibiting off-road motorized vehicle use for big game retrieval in areas with limited travel designations would limit adverse impacts to fish from new trail and road proliferation that may impair water quality. Heavily eroded or washed out roads, if alternative routes exist, are closed and reclaimed and all channel crossings are photo point monitored, providing long-term beneficial impacts to water quality. Campgrounds are not developed under Alternative B, resulting in less adverse impacts due to recreation access than alternatives A and C. However, opportunities for recreational access to some rivers and streams, such as the Laddie Creek and Paint Rock Creek areas, are expanded under this alternative, augmenting potential adverse impacts to fish habitat in these areas.
Forest management actions under Alternative B primarily utilize natural processes to meet forest health goals over commercial thinning or harvesting practices, prohibit clear cuts, and retain old growth forest areas over a 30-year period in HUC Level 4 sub-basins, unless altered by natural processes. Forest management under Alternative B may result in the least amount of short-term adverse impacts to fish habitat due to sedimentation, but also may result in the greatest risk of wildfire that may degrade fish habitat.
Management in special designations under Alternative B would result in the greatest beneficial impacts to fish habitat compared to the other alternatives. Special designations that protect riparian habitat and water quality by restricting surface-disturbing activities include the expanded Carter Mountain, Five Springs Falls, and Upper Owl Creek ACECs, and the proposed Chapman Bench, Clarks Fork Canyon, Rattlesnake Mountain, and Sheep Mountain ACECs, including a total of 43 miles of fishbearing streams (Table 4-9). Under Alternative B, all WSR eligible waterway segments are recommended as suitable for inclusion in the NWSRS, containing 51 miles of fishbearing streams. These segments are closed to locatable mineral entry, mineral leasing, geophysical exploration, and all surface-disturbing activities, providing the greatest amount of protection for water quality and fish habitat for these segments, compared to alternatives A, C, and D. However, there also may be an adverse impact because NWSRS management under Alternative B may limit native species restoration activities, similar to Alternative A.
The BLM manages riparian/wetland areas toward achieving DPC and stabilizes watershed improvement projects to prevent the release of stored sediment if projects no longer meet resource needs, providing the greatest long-term benefit to fish habitat compared to the other alternatives.
Alternative B maintains natural flow regimes in streams supporting fish, providing the greatest beneficial impacts to water quantity compared to the other alternatives. Fencing of wetlands and riparian areas reduces potential bank degradation and sedimentation from other activities and resources uses, resulting in greater indirect beneficial impacts to fish than Alternative A.
Direct beneficial impacts to fish as a result of proactive management under Alternative B result from restoring important stream segments for fish habitat on 10 lotic miles and 80 lentic acres. Alternative B not only improves existing fish habitat on BLM-administered land, but implements management practices to acquire, develop, and maintain new water sources. Alternative B requires mitigation that includes minimum pool depths and adequate public access routes for new impoundment construction on BLM-administered land, and designs and retrofits culverts to allow fish passage. Alternative B provides the greatest amount of proactive management to protect and restore fish habitat.
Impacts to fish habitat from surface disturbance would be similar to those described under Alternative A, although to a greater degree due to increased surface disturbance. Management under Alternative C would result in 245,783 acres of short-term surface disturbance and 41,545 acres of long-term surface disturbance (Table 4-1) resulting in 80 percent and 164 percent more erosion in the short and long term, respectively, than Alternative A. Alternative C provides less restriction on surface-disturbing activities and minerals development, potentially affecting more miles of fishbearing streams, and would cause the greatest impacts to water quality compared to the other alternatives.
Alternative C may result in the greatest amount of change to surface water quantity because the BLM projects the most new federal wells (1,247) and fewer miles of fishbearing streams are in areas closed to minerals development (Table 4-9). Under this alternative, the BLM may not maintain natural flows but encourages water development projects with adequate and required in‐stream flow features to maintain and support fish habitat values. The BLM also uses produced water – in accordance with federal, state, and local laws and regulations – to enhance fish habitat.
With the least area closed (10,636 acres), and the most area open (14,873 acres) to motorized vehicle use, Alternative C is anticipated to result in the greatest adverse impacts from OHV use to water quality compared to the other alternatives. Allowing off-road motorized vehicle use for big game retrieval and dispersed campsite access in areas with limited travel designations would result in impacts similar to Alternative A. Allowing motorized vehicle use on existing roads and trails in The Rivers SRMA would cause greater adverse impacts to fish habitat in this area than the other alternatives. Stabilizing heavily eroded or washed out roads and trails would cause greater short-term surface disturbance and potential sedimentation than the other alternatives. The water quality impacts from recreational development under this alternative are similar to Alternative A. The BLM would not emphasize opportunities for recreational access to certain rivers and streams under this alternative, limiting potential adverse impacts to fish habitat from recreational use. The BLM manages livestock grazing to optimize commodity production while meeting rangeland health standards, not to provide for the enhancement of other resources, and allows the placement of salt, mineral, or forage supplements to maximize livestock use, regardless of proximity to riparian/wetland areas, resulting in the greatest potential impact to water quality under this alternative.
Forest management actions under Alternative C generally prioritize resource use over forest health, although Alternative C provides for retaining old growth forests, similar to Alternative B. Logging, timbering, salvage, and silviculture techniques are used to maintain a desirable forest condition that is determined primarily by commercial or economic objectives. Alternative C allows clear cuts up to 100 acres, which would result in greater adverse impacts to water quality than under alternatives A and B.
Spanish Point Karst (designated under all alternatives) is the only ACEC that benefits water quality by restricting surface-disturbing activities and pesticide application; the only other ACEC designated under Alternative C, Brown/Howe Dinosaur Area, is managed to mitigate surface-disturbing activities, but generally allows mineral development and other types of surface-disturbing activities. Under this alternative, none of the WSR eligible waterway segments are recommended as suitable for inclusion in the NWSRS; these areas would be released to other uses and no special management actions would be applied. Under Alternative C, special designations do not provide any substantial beneficial impact to surface water quality or fisheries habitat.
Riparian/wetland areas are managed to achieve PFC, similar to Alternative A; however, Alternative C emphasizes those areas functioning at-risk with a downward trend or in nonfunctioning condition. Alternative C would provide fewer benefits to fish habitat than Alternative B because watershed improvement projects would be stabilized on a case-by-case basis. In addition, Alternative C has the most potential to adversely impact fish habitat because it would allow surface-disturbing activities in riparian/wetland areas and floodplains on a case-by-case basis. Allowing these types of activities could cause bank degradation, sedimentation, and changes to water quality.
Encouraging water developments that enhance adequate in‐stream flow would result in beneficial impacts to fish habitat under Alternative C; however, these impacts may be less than alternatives A and B. Fencing of springs and their associated wetlands reduces bank degradation and sedimentation in site-specific areas, resulting in indirect beneficial impacts to fish habitat in those areas and potentially downstream of those areas. These beneficial impacts are anticipated to be less than alternatives B and D, but greater than Alternative A.
The direct beneficial impacts to fish from proactive management under Alternative C are less than under the other alternatives. Restoration efforts of stream segments and fisheries habitat are the same as Alternative A. In general, Alternative C only manages to improve fish habitat or maintain viable fisheries in accordance with required law or policy, while some management actions under alternatives A and D and all management actions under Alternative B surpasses these requirements.
Impacts to fish habitat from surface disturbance would be similar to those described under Alternative A. Alternative D is projected to result in slightly more short-term surface disturbance (Table 4-1) that is estimated to result in a 3 percent and 17 percent increase in erosion in the short and long term, respectively. However, reclamation practices under this alternative, as they are more stringent than those under Alternative A, may limit soil erosion to a greater degree resulting in fewer adverse impacts to fishbearing streams. Additionally, Alternative D provides more restrictions on surface-disturbing activities and minerals development that could affect fishbearing streams than Alternative A.
Minerals development under Alternative D would result in similar adverse impacts to fish habitat as under Alternative A, but to a greater degree. Alternative D closes more area to oil and gas development that drains into fishbearing streams than Alternative A, but less area to locatable minerals development. Since a greater amount of surface disturbance is projected to result from locatable minerals development, Alternative D may result in greater adverse impacts to fish habitat from minerals development than Alternative A. Alternative D is anticipated to develop fewer new federal wells than alternatives A and C, but more than Alternative B with proportional adverse impacts to water quantity that may affect fish habitat.
Travel and transportation management under Alternative D would result in less adverse impacts than alternatives A and C, but more than Alternative B. Motorized vehicle use under Alternative D would result in less adverse impacts than Alternative A, because the BLM closes a similar amount of acreage to motorized vehicle use but limits 34 percent more area to designated roads and trails. More lands are open to cross-country motorized travel, but these areas are not in close proximity to fish habitat and would not result in direct adverse impacts. Restricting off-road motorized and mechanized travel for big game retrieval to within 300 feet of established roads provided there is no resource damage and no new routes are created would result in less adverse impacts to fish habitat than Alternative A. Potential adverse impacts from recreational access to fish habitat, such as the Paint Rock, Laddie, and Canyon Creeks and the North and South Forks of the Shoshone River would result in similar adverse impacts to alternatives A and B, but to a greater degree. Impacts to fish habitat from recreational development and livestock grazing management under Alternative D would be similar to those under Alternative A.
Forest management actions under Alternative D would result in impacts similar to Alternative A, except for allowing clear cuts up to 100 acres, which would result in adverse impacts similar to Alternative C.
Special designations under Alternative D would result in similar beneficial impacts as those under Alternative A, but to a greater degree from closing the Upper Owl Creek and Five Springs Falls ACECs to oil and gas leasing. Designating the Clarks Fork Canyon ACEC would result in beneficial impacts by protecting additional fish habitat under Alternative D. By not recommending any of the WSR eligible waterway segments as suitable for inclusion in the NWSRS, Alternative D would result in fewer beneficial impacts from fish habitat protection afforded by this special designation under alternatives A and B; however, Alternative D would result in fewer limitations to native species restoration activities.
Riparian/wetland resources management under Alternative D would result in similar beneficial impacts to those under Alternative A, but to a greater degree. More adverse impacts may result to fish habitat by encouraging the maintenance of natural flow regimes only in prioritized streams; however, developing watershed improvement practices similar to those under Alternative B plus applying BMPs in cooperation with stakeholders would result in greater beneficial impacts than under Alternative A. Fencing reservoirs and riparian areas would result in similar beneficial impacts as those under Alternative B. Surface-disturbance restrictions around waters of the state and riparian/wetland areas would result in similar beneficial impacts to those under Alternative A.
Direct beneficial impacts to fish as a result of proactive management under Alternative D would be similar to those under Alternative A, although to a greater extent. Avoiding surface-disturbing activities around WGFD-rated Class 1 or 2 fisheries up to ¼ mile would likely result in greater beneficial impacts than alternatives A and C. Intensively managing perennial streams to become fish habitat, restoring important stream segments for fisheries habitat on a priority basis, encouraging minimum pool management in existing reservoirs, and designing or retrofitting culverts to allow fish passage on a priority basis would result in beneficial impacts similar to, or greater than, those under Alternative A.