Appendix D – Environmental and Recreational Assessment Methodology and Framework South Platte Basin Implementation Plan South Platte Basin Roundtable/Metro Basin Roundtable April 17, 2015 Appendix D – Environmental and Recreational Assessment Methodology and Framework South Platte Basin Implementation Plan Contents 1 Environmental and Recreational Protections Assessment Methodology ........................................... 5 2 Projects Assessment ........................................................................................................................... 5 3 Discussion of Methodology and Framework ....................................................................................... 6 3.1 General Basin-Wide Methodology ............................................................................................ 7 3.2 Stream Mile Representation Framework ................................................................................. 16 3.3 Stream Mile Representation Framework Overview ................................................................ 18 4 Projects .............................................................................................................................................. 19 4.1 Instream Flows ........................................................................................................................ 20 4.2 Channel Restoration ................................................................................................................ 20 4.3 Stewardship Projects ............................................................................................................... 20 4.4 Species Reintroduction ........................................................................................................... 21 4.5 Cooperative and Multi-Purpose Projects ................................................................................. 22 4.6 South Platte Basin Master Plans ............................................................................................. 22 4.7 Sufficiency of Projects ............................................................................................................. 22 5 Project Examples .............................................................................................................................. 23 5.1 Northern Colorado Region ...................................................................................................... 23 5.1.1 Example Projects – Northern Region ......................................................................... 24 5.1.2 Example Area Analysis – St. Vrain Creek at Lyons ................................................... 26 Stream Mile Representation Analysis .................................................................. 26 Streamflow Analysis ............................................................................................. 28 General Discussion and Recommendations ........................................................ 41 5.2 Upper Mountain Region (Headwaters Areas) ......................................................................... 42 5.2.1 Example Projects – Upper Mountain Region ............................................................. 42 5.2.2 Example Area Analysis – South Platte River above Elevenmile Reservoir ............... 45 Stream Mile Representation Analysis .................................................................. 45 Streamflow Analysis ............................................................................................. 48 General Discussion and Recommendations ........................................................ 60 5.3 Metro Region ........................................................................................................................... 61 5.3.1 Example Projects – Metro Region .............................................................................. 61 5.3.2 Example Area Analysis – South Platte River below Chatfield Reservoir ................... 63 Stream Mile Representation Framework ............................................................. 63 Streamflow Analysis ............................................................................................. 65 General Discussion and Recommendations ........................................................ 75 5.4 Plains (Lower South Platte Region) ........................................................................................ 76 5.4.1 Example Projects – Lower South Platte Region ........................................................ 77 5.4.2 Example Area Analysis – South Platte River at Balzac ............................................. 80 Stream Mile Representation Framework ............................................................. 80 Streamflow Analysis ............................................................................................. 82 General Discussion and Recommendations ........................................................ 94 5.5 Project Example Summary ...................................................................................................... 95 6 Environmental and Recreational Projects List .................................................................................. 95 7 Additional Analyses Needed ........................................................................................................... 111 8 Challenges to Assessment .............................................................................................................. 112 9 Data Gaps ....................................................................................................................................... 112 9.1 Data Limitations ..................................................................................................................... 112 9.2 Recommendations ................................................................................................................ 114 References ................................................................................................................................................ 116 April 17, 2015 | i Appendix D – Environmental and Recreational Assessment Methodology and Framework South Platte Basin Implementation Plan Tables Table 1 - South Platte Basin Attributes ......................................................................................................... 8 Table 2 - South Platte Basin Percent Occurrence by Attribute in Focus Areas .......................................... 10 Table 3 - Attributes by Category ................................................................................................................. 13 Table 4 - St. Vrain Creek at Lyons - General Flow Recommendations (in cfs) .......................................... 30 Table 5 - South Platte River above Elevenmile - General Flow Recommendations (in cfs) ...................... 49 Table 6 - South Platte River below Chatfield - General Flow Recommendations (in cfs) .......................... 67 Table 7 - South Platte River at Balzac - General Flow Recommendations (in cfs) .................................... 84 Table 8 - Environmental and Recreational Projects (based on SWSI 2010) .............................................. 96 Table 9 - Additional Identified Environmental and Recreational Projects ................................................. 108 Figures Figure 2-1 Nonconsumptive (Environmental and Recreational) Projects and Methods Decision Tree .................................................................................................................................................. 6 Figure 3-1 - Relationship between Environmental Attributes ...................................................................... 11 Figure 3-2 - Relationship between Recreational Attributes ........................................................................ 12 Figure 3-3- Illustration of General Basin-Wide Methodology ...................................................................... 15 Figure 3-4 - Measurable Outcome Quantification ....................................................................................... 15 Figure 3-5 - Stream Mile Representation Framework Workflow Overview ................................................. 18 Figure 5-1. South Platte Northern Environmental and Recreational Enhancements ................................. 25 Figure 5-2 - St. Vrain at Lyons Example Area Map .................................................................................... 27 Figure 5-3 – Time Series Hydrograph of St. Vrain Creek at Lyons (Gage: SVCLYOCO, 06724000) ...................................................................................................................................... 29 Figure 5-4 - Hydrograph comparison to available environmental and recreational flow information - 2002 ............................................................................................................................................. 32 Figure 5-5 - Hydrograph comparison to available environmental and recreational flow information - 2003 ............................................................................................................................................. 33 Figure 5-6 - Hydrograph comparison to available environmental and recreational flow information - 2004 ............................................................................................................................................. 34 Figure