Arapaho and Roosevelt National Forests and Pawnee National Grassland Oil and Gas Leasing Analysis Fisheries Resource Report Prepared by Matthew P. Fairchild Date June 30, 2014 ARP Oil and Gas Leasing Analysis Table of Contents Fisheries and Aquatic Resource Issues ................................................................................... 1 Affected Environment for Fisheries ........................................................................................ 1 Amount and Distribution of Aquatic Habitat .......................................................................... 2 Current Human Disturbances and Threats to Aquatic Habitats .............................................. 6 Aquatic Communities and Aquatic Species Distributions ...................................................... 6 Environmental Consequences ................................................................................................ 11 Methodology ......................................................................................................................... 11 Consequences of Water Depletions and Consumptive Use .................................................. 12 Consequences of Habitat Sedimentation ............................................................................... 14 Consequences of Environmental Contaminants to Aquatic Habitat ..................................... 17 Consequences of Habitat Fragmentation ............................................................................... 22 Determination of Effects to Species and Rationale ............................................................... 24 Regulatory Framework ............................................................................................................. 29 Grasslands Land Management Areas .................................................................................... 29 Desired Condition ................................................................................................................. 30 Executive Orders ................................................................................................................... 31 References ................................................................................................................................. 32 List of Tables Table 1. Summary of the amount and distribution of aquatic habitat types across the Pawnee National Grassland, Weld County, Colorado. ......................................................................... 3 Table 2. The list of aquatic species for which environmental impacts have been examined in the Draft Environmental Impact Statement. Includes special status and reason for in depth analysis. Note: Pallid sturgeon is included as federally-listed species of Platte River Ecosystem downstream of this project area in Nebraska. ....................................................... 7 Table 3. Consequences of water depletions compared among alternatives. .................................. 13 Table 4. Consequences of habitat sedimentation to 33 miles of suitable aquatic habitats on the Pawnee National Grassland compared among alternatives. .................................................. 16 Table 5. Concentration of oil & gas related constituents (mg/L) in surface water, ground water, and produced water within 0.25 mile of PNG lands, Weld Co. An asterisk (*) indicates values exceeds known toxicity level for fish or water quality standard. N-Hexane, naphthalene, methane, magnesium, iron, oil & grease, fluoride, ethylbenzene, bicarbonate, calcium, chromium, barium, arsenic, strontium, sulfate, diesel organics, gasoline organics, thorium, and xylenes were detected but below known toxicity values for fish. (1) Value is just under known toxicity level, but reproductive physiology is likely affected at this level.19 Table 6. Consequences of habitat contamination compared among alternatives. ......................... 21 Table 7. Distribution of potential fragmentation sites along streams on the Pawnee National Grassland, Weld Co., Colorado. GIS generated results from Colorado Division of Water Resources and USDA Forest Service. ................................................................................... 22 Table 8. Consequences of habitat fragmentation compared among alternatives. ......................... 24 Table 9. Summary of the distribution, extent, and current status of fish occurrence in occupied aquatic habitats on the PNG, Weld Co, Colorado. The proportion of habitat at high, moderate, and low risk are indicated for each drainage. Superscripts indicated streams historically occupied by plain topminnow (1) and northern plains killifish (2). ................... 26 i ARP Oil and Gas Leasing Analysis List of Figures Figure 1. Persistent aquatic habitat feature on the Pawnee National Grassland, Kibben Allotment grazing exclosure. .................................................................................................................... 1 Figure 2. Water level changes in perennial surface water habitats from July 2012 to October 2013 in the South Pawnee Creek drainage, Pawnee National Grassland, Weld County, Colorado. Water levels above dashed lines approximate periods when surface flow were present. .................................................................................................................................... 2 Figure 3. Maps of the East and West units of the Pawnee National Grassland depicted to distribution of movement corridors, suitable aquatic habitat, and occupied aquatic habitat, Weld Cty, Colorado. ................................................................................................................ 5 Figure 4. Photograph of a plains topminnow collected from the South Pawnee Creek area of the Pawnee National Grassland, 2012. .......................................................................................... 8 Figure 5. Photograph of a northern plains killifish collected from Owl Creek, Pawnee National Grassland, 2013. ...................................................................................................................... 9 Figure 6. Quantity of produced water (blue line) and number of spills (red line) reported to Colorado Oil and Gas Conservation Commission for Weld County Colorado from 2004 to 2013. Source: Colorado Oil and Gas Conservation Commission Online Database. ............ 18 ii ARP Oil and Gas Leasing Analysis Figure 1. Persistent aquatic habitat feature on the Pawnee National Grassland, Kibben Allotment grazing exclosure. Fisheries and Aquatic Resource Issues 1. Suitable aquatic habitat either supporting or capable of supporting native fishes of the Pawnee National Grassland (PNG) 2. Surface and groundwater sources that supply water to sustain suitable habitats 3. Connection habitat that links patches of suitable aquatic habitat within the stream networks of the PNG 4. Risks to population persistence for plains topminnow on PNG 5. Risks to species viability for plains topminnow and plains killifish on PNG Affected Environment for Fisheries The Pawnee National Grassland contains several land parcels among 39 sixth field (i.e., 6 digit hydrologic units) prairie watersheds on a portion of Colorado’s eastern plain. All of the plains streams occurring on the grassland are tributary to the South Platte River. This is a portion of the western Great Plains that extends from eastern Colorado and eastern Wyoming east across much of Nebraska, portions of South Dakota, and into Kansas. These prairie watersheds originate on the plains and have developed into a loosely parallel drainage pattern, exhibiting a hydrology characterized by flooding and drying. Resultantly, few of these streams are continuously 1 ARP Oil and Gas Leasing Analysis perennial. Rather, most streams are intermittent with short sections of perennial surface water that occur as semi-connected pools along the streamcourse (Figure 1). Surface water within these clusters of aquatic habitat is maintained by stochastic precipitation events great enough to generate overland flow during and shortly following storm events and via groundwater that is exposed to the surface where pool-like depressions occur along the streamcourse (Figure 2). Based on 75 years of precipitation data, the greatest amount of precipitation falls from April through June; however, some areas experience a wet monsoon season in August and September (USDA Forest Service, unpublished data). These wet periods likely generate sufficient stream flow to connect separate perennial habitats within a 10-year period or less. Although small and unseen by most, these unique aquatic habitats occur in most of the intermittent stream channels across the western Great Plains, including the Pawnee National Grassland. 5 Box 4 Kibben 3 2 1 0 -1 -2 Water level (feet) -3 -4 -5 -6 Jul-12 Oct-12 Jan-13 May-13 Aug-13 Nov-13 Figure 2. Water level changes in perennial surface water habitats from July 2012 to October 2013 in the South Pawnee Creek drainage, Pawnee National Grassland, Weld County, Colorado. Water levels above dashed lines approximate periods when surface flow were present. Amount and Distribution of Aquatic Habitat Although the total amount of aquatic habitats on the Pawnee National Grasslands may be quite limited during a snapshot of time, the linear networks in which those habitats occur are large, covering multiple 40,000 acre watersheds that stretch from southeastern Wyoming to the South Platte River. Hydrologic data used to classify