USER’S GUIDE The Summit County Conservation Inventory conducted by the Colorado Natural Heritage Program consists of two essentially distinct projects that are highly integrated with respect to methodology, field work, and coordination with Summit County government. This report reflects the separate nature of the projects by being organized in a two volume set. Both projects utilized the same Natural Heritage methodology that is used throughout North America, and both searched for and assessed the plants, animals, and plant communities on the Colorado Natural Heritage Program’s List of rare and imperiled elements of biodiversity. Each volume prioritizes potential conservation sites based on the relative significance of the biodiversity they support and the urgency for protection of the site. All information explaining Natural Heritage methodology and ranks is repeated in each volume, so that each volume can stand alone and be used independently of the other. Volume I presents all potential conservation sites identified in Summit County that support rare and imperiled plants, animals, and significant plant communities, including wetland and riparian areas. Volume II focuses exclusively on wetland and riparian areas. Volume II also presents “locally significant areas.” These are sites that are among the most important wetlands in Summit County, but they are not unique from a national or statewide perspective, therefore these sites did not receive a Biodiversity Rank. Additionally, Volume II presents an assessment of the wetland functions performed by each site that was surveyed. These functional assessments are intended to provide the user with a more complete picture of the value wetlands and riparian areas provide to Summit County residents. i ACKNOWLEDGMENTS Financial support for this study was provided by a grant from the Environmental Protection Agency (EPA), Region VIII, through the Colorado Department of Natural Resources (DNR), with in-kind services provided by the Colorado Natural Heritage Program. We greatly appreciate the support and assistance of Doug Robotham and Deborah Mellblom of the Department of Natural Resources and Sarah Fowler and David Rathke of the U.S. Environmental Protection Agency, Region VIII. The Colorado Natural Heritage Program would like to acknowledge and sincerely thank Summit County Government and the Summit County Conservation Inventory Guidance Committee which gave us invaluable support and advice. The following individuals and groups participated in this role: United States Forest Service Dillon Ranger District, Colorado Division of Wildlife, the Towns of Breckenridge, Frisco, Dillon, Montezuma, Silverthorne, and Blue River, Keystone Science School, Continental Divide Land Trust, Sierra Club, Open Space Advisory Council, Northwest Colorado Council of Governments, Trout Unlimited, Bureau of Land Management Kremmling Resource Area, U.S. Army Corps of Engineers, Todd Robertson with the Summit County Open Space and Trails Department, Chris Hawkins and Steve Hill with the Summit County Planning Department, Summit County Board of County Commissioners, and the Summit County GIS Department. Special thanks to Dixie Kunh in Summit County Human Resources Department for the coordination of summer housing for the field crew. We appreciate the work of Phil Ecklund for his help with an aerial reconnaissance. Many thanks to Monique Gilbert, a volunteer with the Colorado Division of Wildlife, who provided us expertise with the boreal toad surveys. Many people at the Colorado Natural Heritage Program contributed to the success of this project, especially, Liz Phillips, Brad Lambert, and Phil Busteed for processing the field data and Doug Shinnemann, Leanne Small, and Amy Lavender for their help with the GIS maps. Finally, we thank the many landowners (too numerous to name here) for their cooperation in allowing us access to their land to conduct the inventory. ii TABLE OF CONTENTS USER’S GUIDE .............................................................................................................................I ACKNOWLEDGMENTS ........................................................................................................... II TABLE OF CONTENTS ...........................................................................................................III LIST OF FIGURES .................................................................................................................VIII EXECUTIVE SUMMARY ...........................................................................................................1 RECOMMENDATIONS...............................................................................................................3 PROJECT BACKGROUND AND PURPOSE ...........................................................................4 Study Area .......................................................................................................................................5 THE NATURAL HERITAGE NETWORK AND BIODIVERSITY .......................................6 What is Biological Diversity?..........................................................................................................7 Colorado’s Natural Heritage Program .............................................................................................8 The Natural Heritage Ranking System ............................................................................................9 Protection Urgency Ranks .........................................................................................................11 Management Urgency Ranks.....................................................................................................11 Element Occurrence Ranking ....................................................................................................12 Proposed Conservation Sites .........................................................................................................13 Proposed Conservation Planning Boundaries................................................................................13 Off-Site Considerations .................................................................................................................14 Ranking of Proposed Conservation Sites.......................................................................................15 Legal Designations ........................................................................................................................15 WETLAND DEFINITIONS AND REGULATIONS ...............................................................17 Wetland Definitions.......................................................................................................................17 Wetland Function and Values........................................................................................................18 Wetland Regulation in Summit County and throughout Colorado................................................19 METHODS ...................................................................................................................................21 Survey Site Selection.....................................................................................................................21 Site Assessment .............................................................................................................................21 Plant Communities.........................................................................................................................23 iii WETLAND FUNCTIONS AND VALUES..................................................................................24 Ground Water Recharge and Discharge ........................................................................................24 Flood Storage.................................................................................................................................25 Shoreline Anchoring ......................................................................................................................25 Sediment Trapping.........................................................................................................................25 Long and Short Term Nutrient Removal .......................................................................................25 Production Export (Downstream and Within Food Chain Support)..............................................26 Habitat............................................................................................................................................26 Recreation (Active and Passive)....................................................................................................27 Uniqueness/Heritage Value ...........................................................................................................27 HYDROGEOMORPHIC (HGM) APPROACH TO WETLAND FUNCTION ASSESSMENT .............................................................................................................................28 RESULTS SUMMIT COUNTY SITES OF BIODIVERSITY SIGNIFICANCE ................30 UPPER BLUE RIVER BASIN ...................................................................................................33 Blue Lakes .....................................................................................................................................34 Cucumber Gulch ............................................................................................................................41