Root River Watershed Monitoring and Assessment Report
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z c Root River Watershed Monitoring and Assessment Report June 2012 Acknowledgements MPCA Watershed Report Development Team: Michael Koschak, Mike Walerak, Pam Anderson, Dan Helwig, Bruce Monson, Dave Christopherson, David Duffey, Andrew Streitz Contributors: Citizen Stream Monitoring Program Volunteers Minnesota Department of Natural Resources Minnesota Department of Health Minnesota Department of Agriculture Fillmore County Soil and Water Conservation District The MPCA is reducing printing and mailing costs by using the Internet to distribute reports and information to a wider audience. Visit our Website for more information. MPCA reports are printed on 100% post-consumer recycled content paper manufactured without chlorine or chlorine derivatives. Project dollars provided by the Clean Water Fund (from the Clean Water, Land and Legacy Amendment). Minnesota Pollution Control Agency 520 Lafayette Road North | Saint Paul, MN 55155-4194 | www.pca.state.mn.us | 651-296-6300 Toll free 800-657-3864 | TTY 651-282-5332 This report is available in alternative formats upon request, and online at www.pca.state.mn.us Document number: wq-ws3-070400086 Contents Executive Summary ................................................................................................................. 1 I. Introduction ....................................................................................................................... 2 II. The Watershed Monitoring Approach ................................................................................ 3 Load monitoring network ..................................................................................................................... 3 Intensive watershed monitoring ........................................................................................................... 4 III. Assessment Methodology .................................................................................................. 7 Water quality standards ....................................................................................................................... 7 Assessment units .................................................................................................................................. 7 Determining use attainment status ....................................................................................................... 8 Data management ............................................................................................................................... 9 Period of record .................................................................................................................................... 9 IV. The Root River Watershed Overview ............................................................................... 10 Land use summary .............................................................................................................................. 11 Surface water hydrology ..................................................................................................................... 12 Climate and precipitation ................................................................................................................... 13 Hydrology and groundwater quality ................................................................................................... 14 V. Watershed-Wide Data Collection Methodology ............................................................... 16 Load monitoring ................................................................................................................................. 16 Stream water sampling ...................................................................................................................... 17 Stream biological sampling ................................................................................................................. 17 Fish contaminants .............................................................................................................................. 18 VI. Individual Watershed Results .......................................................................................... 18 HUC-11 watershed units ..................................................................................................................... 18 Stream assessments ........................................................................................................................... 19 Channelized stream evaluations ......................................................................................................... 19 Stream habitat results ........................................................................................................................ 20 Watershed outlet water chemistry results........................................................................................... 20 VII. Watershed-Wide Results and Discussion ....................................................................... 152 Pollutant load monitoring ................................................................................................................. 152 Stream water quality ........................................................................................................................ 158 Fish contaminants results ................................................................................................................. 161 Groundwater monitoring .................................................................................................................. 163 Water chemistry trends .................................................................................................................... 165 Summary and Recommendations ........................................................................................ 171 References........................................................................................................................... 172 Appendix 1: Water chemistry definitions ........................................................................................... 173 Appendix 2: Biological monitoring stations in the Root River Watershed ........................................... 175 Appendix 3: Intensive watershed monitoring stations in the Root River Watershed ........................... 179 Appendix 4: AUID table of results (by parameter and beneficial use) ................................................. 180 Appendix 5: Minnesota statewide IBI thresholds and confidence limits ............................................. 188 Appendix 2: Biological monitoring results-fish IBI .............................................................................. 189 Appendix 3: Biological monitoring results - macroinvertebrate IBI .................................................... 198 Appendix 8: Good/fair/poor thresholds for biological stations on non-assessed channelized AUIDs .. 207 Appendix 9: Channelized stream AUID- fish IBI .................................................................................. 208 Appendix 10: Channelized stream AUID - macroinvertebrate IBI........................................................ 209 Executive Summary This assessment report is the first in a series of reports for watershed work being conducted in the Root River watershed. The results of surface water monitoring activities in the Root River watershed are reported here. Subsequent reports will explain stressor identification, total maximum daily loads, and restoration and protection plans for the watershed. The Root River watershed (07040008) covers 1,064,961 acres in southeast Minnesota within the Lower Mississippi River Basin. Agriculture is the most prevalent land use in the watershed. The watershed’s wealth of surface waters is a valuable resource for aquatic recreation and its health is essential to resident aquatic life. In 2008 the Minnesota Pollution Control Agency (MPCA) undertook an intensive watershed monitoring effort of the Root River watershed’s surface waters. A total of 109 sites were sampled for biology at the outlets of variable sized sub-watersheds within the Root River watershed. These locations included the mouth of the Root River, the outlets of its major tributaries, and the outlets of headwater tributaries. As part of this effort, the MPCA also joined with the Fillmore County Soil and Water Conservation District who completed stream water chemistry sampling at the outlets of the Root River’s 15 major subwatersheds during 2009. In 2011, a holistic approach was taken to assess all of the watershed’s surface water bodies for aquatic life, recreation, and fish consumption use support, where data was available. A total of 142 stream reaches were sampled for fish, and 139 stream reaches were sampled for macroinvertebrates in the Root River watershed during the assessment window. Eighty-six streams were assessed for aquatic life support and eighteen were assessed for aquatic recreation in this effort. Not all streams were able to be assessed due to insufficient data, modified channel condition, or “limited resources waters” water quality designation. Forty-three streams were found to be supporting of aquatic life use in the Root River watershed. Aquatic biological impairments were found scattered throughout the watershed where assessments were made (see Fig. 46 for a map of impaired sites). Forty-three new impairments of aquatic life have been added to the Root River watershed during the 2011 assessment cycle. Eighteen