20142014 AANNUALNNUAL RREPORTEPORT ONON AACTIVITIESCTIVITIES CherryCherry CreekCreek BasinBasin WaterWater QualityQuality AuthorityAuthority March 31, 2015 2014 Annual Report on Activities Cherry Creek Basin Water Quality Authority Cherry Creek Basin Water Quality Authority Chuck Reid, Manager CliftonLarsonAllen LLP 8390 E. Crescent Parkway, Suite 500 Greenwood Village, CO 80111 Phone: 303-779-4525 Email: [email protected] PREPARED BY: Leonard Rice Engineers, Inc. William P. Ruzzo, P.E., L.L.C. GEI Consultants, Inc. JRS Engineering Consultant LLC Cherry Creek Land Use Agencies and Utilities Cherry Creek Stewardship Partners TABLE OF CONTENTS TABLE OF CONTENTS ............................................................................................................................. i LIST OF FIGURES .................................................................................................................................... iii LIST OF TABLES ...................................................................................................................................... iv LIST OF MAPS .......................................................................................................................................... iv CONTROL REGULATION 72 REPORTING REQUIREMENTS CHECKLIST ................................. v LIST OF ACRONYMS AND ABBREVIATIONS .................................................................................. vii EXECUTIVE SUMMARY ............................................................................................................................. ES-1 1 The Authority ..................................................................................................................................... 1-1 1.1 Regulatory History ......................................................................................................................................... 1-2 1.2 Financial Matters ........................................................................................................................................... 1-5 1.3 Web Links to the Authority ............................................................................................................................. 1-6 2 Description of Cherry Creek Reservoir Watershed ............................................................................ 2-1 2.1 Cherry Creek Reservoir Model ...................................................................................................................... 2-2 2.2 Public Information and Education by Authority and Partners......................................................................... 2-3 3 Point Sources ..................................................................................................................................... 3-1 3.1 Limits and Data Summary Requirements for Phosphorus and Nitrogen ....................................................... 3-5 3.2 Monthly Phosphorus Concentrations ............................................................................................................. 3-7 3.3 Monthly Nitrogen Concentrations ................................................................................................................ 3-10 3.4 Permit Compliance ...................................................................................................................................... 3-11 3.5 Permit Renewal Timing and Process ........................................................................................................... 3-12 3.6 Other Point Source Discharge Permits in the Watershed ............................................................................ 3-13 3.7 Onsite Wastewater Treatment Systems ...................................................................................................... 3-15 3.8 Approved Site Applications .......................................................................................................................... 3-16 3.8.1 Authority’s Role in Site Application Process ....................................................................................... 3-17 3.9 Effectiveness in Reducing Nutrient Concentrations ..................................................................................... 3-18 4 Regulated Stormwater Source Controls ............................................................................................ 4-1 4.1 MS4 General Permit Renewal Process ......................................................................................................... 4-3 4.2 Sediment and Erosion Control Permits .......................................................................................................... 4-3 4.3 Adoption and Implementation of BMPs by Local Governments ..................................................................... 4-3 4.4 Construction BMPs ........................................................................................................................................ 4-4 4.5 Post-Construction BMPs ............................................................................................................................... 4-4 4.6 Flood Control Facilities Retrofitting, Inspection, and Maintenance Actions ................................................... 4-6 4.7 Effectiveness in Reducing Phosphorus Concentrations ................................................................................ 4-7 4.8 Funding of Regulated Stormwater Projects ................................................................................................. 4-10 i 4.9 Monitoring of Regulated Stormwater Projects ............................................................................................. 4-10 4.10 Public Information and Education Actions of MS4s ..................................................................................... 4-10 5 Other Nonpoint Sources .................................................................................................................... 5-1 5.1 Update list of PRFs Implemented .................................................................................................................. 5-1 5.2 Overview of PRFs to Date ............................................................................................................................. 5-5 5.3 Floodplain Preservation/Conservation Easements ........................................................................................ 5-9 5.4 Monitoring of PRFs ........................................................................................................................................ 5-9 5.5 PRF Effectiveness in Reducing Phosphorus Concentrations ........................................................................ 5-9 5.5.1 Cottonwood Creek Peoria Pond ......................................................................................................... 5-11 5.5.2 Cottonwood Creek Reclamation and Perimeter Pond ........................................................................ 5-13 5.5.3 McMurdo Gulch Stream Reclamation ................................................................................................ 5-15 5.6 Funding of PRFs and Nonpoint Source Projects ......................................................................................... 5-15 5.7 Annual Inspection of PRFs .......................................................................................................................... 5-16 6 Riparian and Wetlands Protection ..................................................................................................... 6-1 6.1 Regulatory Protection .................................................................................................................................... 6-1 6.2 Land Development Activities ......................................................................................................................... 6-2 6.3 Protection, Enhancement, and Restoration Actions ...................................................................................... 6-2 7 Monitoring ......................................................................................................................................... 7-1 7.1 Sampling Sites ............................................................................................................................................... 7-1 7.2 Reservoir Water Quality ................................................................................................................................ 7-3 7.2.1 2014 Reservoir Water Quality .............................................................................................................. 7-3 7.3 2014 Reservoir Inflows – Outflows and Total Phosphorus Loads ............................................................... 7-10 7.4 Reservoir Management Strategy ................................................................................................................. 7-12 7.5 2014 Phytoplankton and Cyanotoxins ......................................................................................................... 7-13 7.6 Long-Term Phytoplankton ........................................................................................................................... 7-14 7.7 Zooplankton ................................................................................................................................................. 7-16 7.8 Water Quality