St. Vrain Basin Watershed-Based Plan: Boulder Creek, St. Vrain Creek and Tributaries September 2015 ES-i St. Vrain Basin Watershed-Based Plan Report Preparation The Colorado Department of Public Health and Environment provided Nonpoint Source grant funds from the U.S. Environmental Protection Agency to enable development of this report. Substantial matching contributions (both cash and in-kind) were provided by the City of Boulder, Boulder County, and the Keep It Clean Partnership. This report was prepared by the Keep It Clean Partnership and Wright Water Engineers, Inc. The following individuals supported this effort by providing information, review and participation in stakeholder meetings: Watershed Stakeholders: Janice Lopitz, Keep It Clean Partnership Coordinator Erin Dodge, Boulder County, Water Quality Program Coordinator David Bell, Boulder County, Agricultural Resources Manager Rob Alexander, Boulder County Parks and Open Space, Senior Agricultural Resource Specialist Chase Dryden, Boulder County Parks and Open Space, Agricultural Resource Specialist Bret Linenfelser, City of Boulder, Public Works/Utilities Water Quality Manager Russ Sands, City of Boulder, Public Works/Utilities Watershed Sustainability/Outreach Supervisor Andy Taylor, City of Boulder, Public Works/Utilities Water Quality Inspector Jon Mays, Town of Erie, Public Works Water and Wastewater Operations Manager Wendi Palmer, Town of Erie, Public Works Civil Engineer Mick Forrester, City of Lafayette, Public Works Water Reclamation Superintendent Justin Elkins, City of Louisville, Public Works Environmental Specialist Cameron Fowlkes, City of Louisville, Public Works Civil Engineer Kathryne Marko, City of Longmont, Public Works/Natural Resources Civil Engineer Cal Youngberg, City of Longmont, Public Works/Natural Resources Environmental Services Manager Alex Ariniello, Town of Superior, Public Works and Utilities Director Barb Horn, Colorado Parks and Wildlife, River Watch Coordinator Glenn Patterson, Left Hand Creek Watershed Oversight Group Coordinator Sean Cronin, St. Vrain-Left Hand Water Conservancy District Executive Director Dave Rees, Timberline Aquatics, Owner Grant Administration CDPHE: Lucia Machado, Water Quality Control Division Report Preparation: Jane Clary, Project Manager, Wright Water Engineers, Inc. Andrew Earles, P.E., Ph.D., Wright Water Engineers, Inc. Nicole Reitz, Wright Water Engineers, Inc. Kelly Behling, Wright Water Engineers, Inc. Minor revisions to Watershed Plan completed March 30, 2016. ES-ii St. Vrain Basin Watershed-Based Plan Table of Contents Executive Summary ................................................................................................................ i 1.0 Watershed Characterization and Regulatory Framework ......................................... 1-1 1.1 INTRODUCTION .................................................................................................................... 1-1 1.2 WATERSHED FEATURES ......................................................................................................... 1-3 1.3 MAJOR SUBWATERSHEDS AND GEOGRAPHIC FOCUS................................................................... 1-5 1.3.1 Boulder Creek Subwatershed ............................................................................. 1-7 1.3.2 St. Vrain Creek Subwatershed .......................................................................... 1-10 1.4 LAND USE ......................................................................................................................... 1-11 1.5 POPULATION CHARACTERISTICS ............................................................................................ 1-14 1.6 CDPS-PERMITTED DISCHARGES ............................................................................................ 1-17 1.7 HYDROLOGY AND WATER MANAGEMENT (WATER RIGHTS) ...................................................... 1-19 1.8 GEOLOGY AND MINING ....................................................................................................... 1-24 1.9 SOILS ................................................................................................................................ 1-28 1.10 OIL AND GAS ACTIVITY ........................................................................................................ 1-31 1.11 WILDFIRE HAZARD .............................................................................................................. 1-31 1.12 SEPTEMBER 2013 FLOOD DAMAGE INVENTORY, PLANNING AND MITIGATION ............................. 1-35 1.13 OTHER WATERSHED CHARACTERISTICS AND INVENTORIES ......................................................... 1-36 1.14 INTEGRATION WITH OTHER PLANNING EFFORTS ...................................................................... 1-38 1.15 STREAM STANDARDS AND DESIGNATED USES .......................................................................... 1-41 1.16 IMPAIRED WATERS: 303(D) LISTINGS AND EXISTING TMDLS .................................................... 1-44 1.17 REGULATORY ISSUES AND PROCESSES .................................................................................... 1-47 1.18 CONCLUSION ..................................................................................................................... 1-47 2.0 Watershed Partnerships .......................................................................................... 2-1 2.1 WATERSHED PARTNERS AND STAKEHOLDERS ............................................................................ 2-1 2.2 OUTREACH ACTIVITIES AND TECHNICAL ASSISTANCE ................................................................... 2-2 2.3 CONCLUSION ....................................................................................................................... 2-5 3.0 Scope of Watershed Efforts ..................................................................................... 3-1 3.1 POLLUTANTS OF CONCERN ..................................................................................................... 3-1 3.2 INDICATORS TO MEASURE ENVIRONMENTAL CONDITIONS ........................................................... 3-2 3.3 MISSION AND/OR VISION OF WATERSHED ORGANIZATION .......................................................... 3-2 3.4 GOALS AND OBJECTIVES OF WATERSHED PLAN ......................................................................... 3-2 ES-iii St. Vrain Basin Watershed-Based Plan 3.4.1 Goals ................................................................................................................... 3-3 3.4.2 Objectives ........................................................................................................... 3-3 3.5 ORGANIZATIONAL CONCERNS ................................................................................................. 3-5 4.0 Watershed Information Sources, Monitoring Plan and Data Inventories .................. 4-1 4.1 INFORMATION SOURCES ........................................................................................................ 4-1 4.2 DATA INVENTORIES ............................................................................................................... 4-2 4.3 MONITORING PROGRAM ....................................................................................................... 4-2 4.4 DATA MANAGEMENT AND REPORTING .................................................................................... 4-3 4.5 SUMMARY OF RECOMMENDATIONS FOR MONITORING ............................................................... 4-4 5.0 Data Analysis and Characteristics ............................................................................ 5-1 5.1 DATA MANAGEMENT AND ANALYSIS METHODOLOGIES .............................................................. 5-1 5.2 REVIEW OF POTENTIAL WATER QUALITY ISSUES ......................................................................... 5-1 5.2.1 Primary Pollutants of Interest ............................................................................. 5-1 5.2.2 Pollutants Excluded from Further Analysis ......................................................... 5-6 5.3 IDENTIFIED WATER QUALITY ISSUES....................................................................................... 5-10 5.3.1 E. coli ................................................................................................................. 5-10 5.3.1.1 Boulder Creek ...................................................................................... 5-10 5.3.1.2 Coal Creek Routine Sampling ............................................................... 5-14 5.3.1.3 Coal Creek Special Study (2007-2014) ................................................. 5-18 5.3.1.4 Coal Creek Special Study (2007-2008) ................................................. 5-19 5.3.1.5 St. Vrain Creek/Left Hand Creek/Dry Creek ......................................... 5-22 5.3.1.6 Dry Creek ............................................................................................. 5-27 5.3.2 Metals ............................................................................................................... 5-28 5.3.2.1 Selenium .............................................................................................. 5-28 5.3.2.2 Mining-Related Metals in Left Hand Creek Subwatershed.................. 5-29 5.3.3 pH in Lower Boulder Creek ............................................................................... 5-29 5.3.4 Aquatic Life ......................................................................................................