Northern Integrated Supply Project Environmental Impact Statement Aquatic Biological Resources Technical Report Prepared for: U.S. Army Corps of Engineers Omaha District March 2008 Prepared by: GEI Consultants, Inc. Chadwick Ecological Division 5575 South Sycamore Street, Suite 101 Littleton, CO 80120 CONTENTS 1. Introduction .................................................................................................................1 1.1. Northern Integrated Supply Project ...................................................................1 1.2. No Action Alternative ........................................................................................1 1.3. Group 1—Southern Group .................................................................................2 1.3.1. Erie .........................................................................................................3 1.3.2. Lafayette ................................................................................................3 1.3.3. Lefthand Water District .........................................................................3 1.3.4. No Action Alternative for Southern Group ...........................................3 1.4. Group 2—Northern Group .................................................................................3 1.4.1. Eaton ......................................................................................................4 1.4.2. Severance ...............................................................................................4 1.4.3. Windsor ..................................................................................................4 1.4.4. No Action Alternative for Northern Group ...........................................4 1.5. Group 3—Eastern Group ...................................................................................4 1.5.1. Fort Morgan ...........................................................................................5 1.5.2. Morgan County Quality Water District .................................................5 1.5.3. No Action Alternative for Eastern Group ..............................................5 1.6. Independent Participants ....................................................................................6 1.6.1. CWCWD ................................................................................................6 1.6.2. Evans ......................................................................................................6 1.6.3. Fort Collins-Loveland Water District ....................................................7 1.6.4. Fort Lupton ............................................................................................7 1.7. Action Alternatives—Activities Common to All Alternatives ..........................8 1.7.1. Bureau of Reclamation Subalternatives .................................................8 1.7.2. South Platte Water Conservation Project .............................................13 1.7.3. Diversions from the Cache la Poudre River ........................................13 1.8. Alternative 2—Proposed Action—Glade Reservoir and the SPWCP .............14 1.9. Alternative 3—Cactus Hill Reservoir and the SPWCP ...................................15 1.10. Alternative 4—Glade Reservoir and SPWCP with Agricultural Transfer Lands .................................................................................................16 1.11. Objective ..........................................................................................................17 1.12. Regulatory Framework ....................................................................................18 1.13. Study Area .......................................................................................................20 2. Methods and Analysis ...............................................................................................21 2.1. Existing Environment ......................................................................................21 2.1.1. Existing Data Sources ..........................................................................21 2.1.2. Supplemental Data ...............................................................................25 2.2. Effects Evaluation ............................................................................................30 2.2.1. Approach to Analysis ...........................................................................31 2.2.2. Hydrology ............................................................................................33 i 2.2.3. Instream Flow Incremental Methodology ............................................35 2.2.4. Effects Analysis ...................................................................................41 3. Existing Environment ...............................................................................................44 3.1. Habitat Descriptions.........................................................................................44 3.1.1. Cache la Poudre River .........................................................................44 3.1.2. South Platte River ................................................................................45 3.1.3. Reservoir Sites .....................................................................................45 3.2. Fish Populations ...............................................................................................45 3.2.1. Cache la Poudre River .........................................................................45 3.2.2. South Platte River ................................................................................55 3.3. Macroinvertebrate Populations ........................................................................59 3.3.1. Cache la Poudre River .........................................................................59 3.3.2. South Platte River ................................................................................62 4. Direct Effects Evaluation ..........................................................................................63 4.1. Cache la Poudre River .....................................................................................63 4.1.1. Upstream of Fort Collins .....................................................................63 4.1.2. Near Fort Collins..................................................................................72 4.1.3. Fort Collins to Interstate 25 .................................................................78 4.1.4. Interstate 25 to the Platte River ............................................................84 4.2. South Platte River ............................................................................................91 4.2.1. Cache la Poudre River to the Kersey Gage ..........................................91 4.3. Proposed Reservoirs.........................................................................................97 4.3.1. Glade Reservoir ...................................................................................97 4.3.2. Cactus Hill Reservoir ...........................................................................98 4.3.3. Galeton Reservoir ................................................................................98 4.4. Munroe Canal Diversion ..................................................................................99 5. Cumulative Effects Evaluation .................................................................................99 6. Mitigation ..................................................................................................................99 7. References ...............................................................................................................101 ii TABLES Table 1: Locations and Dates of Supplemental Data Collection on the Cache la Poudre River, Colorado, 2005. .................................................................27 Table 2: Fish Population Data (Presence/Absence) for the Cache la Poudre River 1970-2005. Data from Appendix E, Native Species in Bold. ...........47 Table 3: Fish Density (#/ha) and Other Population Parameters from Supplemental Data Collection Sites on the Cache la Poudre River, 2005. Data from Appendix C, Native Species in Bold. ...............................51 Table 4: Fish Population Data (Presence/Absence) for the South Platte River, 1980-2003. Data from Appendix F, Native Species in Bold. ......................56 Table 5: Summary of Cache la Poudre River Benthic Invertebrate Parameters, 1992-2005. Data from Shieh et al. (1999), USGS (2003), and Appendix D. ..................................................................................................59 Table 6: Benthic Invertebrate Density (Number/m2) and Other Summary Population Parameters for Supplemental Data Collection Sites on the Cache la Poudre River, 2005. Data from Appendix D. X=Present in the Qualitative Sample Only. ........................................................................61 Table 7: Direct Effects Summary for Differences in Flow Among the Action Alternatives Based on Mean-Monthly Flow at the CANGAGE Node on the Cache la Poudre River. ......................................................................68 Table 8: Direct Effects Summary for Differences in Flow Among the Action Alternatives Based on Mean-Monthly Flow at the Main 3 Node on the Cache la Poudre River. ...........................................................................68 Table 9: Direct Effects Summary