Tannery Creek (Little Traverse Bay)
A Scale-Appropriate Watershed Management Plan
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EXECUTIVE SUMMARY
Tip of the Mitt Watershed Council (the Watershed Council), located in Petoskey, Michigan, requested a master’s project team from the University of Michigan (UM) School of Natural Resources and Environment (SNRE) to write a watershed management plan for Tannery Creek, which flows into Little Traverse Bay. Over 16 months in 2012 and 2013, the SNRE team conducted the necessary research and analysis to write a robust scale-appropriate plan for Tannery, a plan that focuses on both restoration and protection in the Tannery Creek watershed. This document firstly contains the primary product from this project: a watershed management plan, which will be submitted by the client to the Department of Environmental Quality for approval. The plan includes a description of the current state of the watershed based on a stream assessment and watershed analysis, the public outreach efforts conducted in conjunction with the plan’s development, and a full set of management recommendations. These management recommendations include goals and objectives, prioritized implementation tasks, and a discussion of how to evaluate progress toward the plan’s goals. Following the watershed management plan, this document contains a description of methodologies for the stream assessment, watershed analysis, and public outreach conducted by the project team (beginning on page 102). Finally, for future reference, this report also contains the raw data and public outreach materials developed in the process of designing the watershed management plan. |
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Stream Assessment. Thanks to previous monitoring efforts by the Watershed Council and the Little Traverse Bay Bands of Odawa Indians (the Tribe), there exists some historical data on the water quality and biological communities of Tannery Creek. To augment and fill in the gaps in this data, the SNRE team conducted a full stream assessment in summer 2012, expanding efforts to include several new sites. The team sampled at five total sites that are representative of the creek’s entire reach: headlands, middle areas with prevalent road–stream crossings, and the creek mouth, which is located in a more developed commercial area. The SNRE team then used an analysis of the historical and newly gathered data to inform management recommendations for the creek. For the most part, the water quality and terrestrial and aquatic habitats of Tannery Creek are in good condition. Primary concerns include debris/litter and altered hydrology, which results in occasional flooding in the lower portion of the creek. The SNRE team recommends a management approach that prioritizes protection efforts.
Watershed Analysis. To better understand the current state of Tannery Creek, the SNRE team conducted an assessment of the full watershed utilizing Geographic Information Systems (GIS) and two specific modeling tools, namely Impervious Land Cover and Long Term Hydrologic Impact Assessment (L-THIA). To aid in this analysis, the SNRE team divided the Tannery Creek Watershed into three distinct sub-watersheds: West Branch, East Branch, and the Lower Watershed. The Impervious Land Cover tool evaluates impervious surface percentages and revealed current problems in the Lower Watershed. The L-THIA model estimates runoff, recharge, and nonpoint pollution for a given area. The team used zoning information from the Bear Creek Township Master Plan to create a “build-out” scenario that projects future runoff volumes for the Tannery Creek watershed. Based on this build-out scenario, it is clear that the East Branch and West Branch portions of the watershed may experience negative impacts of runoff in the future due to development pressures and increased impervious surface levels.
Public Outreach. The SNRE team conducted extensive public outreach and education both to inform the stream assessment and watershed analysis described above and to begin the process of achieving buy-in from local residents and businesses for management recommendations. The team conducted a survey of residents and businesses to explore uses and impressions of the creek. In addition to one-on-one conversations with many residents and business owners, the team conducted two Community Forum meetings in March 2013 to further engage those who live and work in the Tannery Creek watershed. iii
Recommendations. Though current threats to Tannery Creek are primarily from debris/litter and altered hydrology, the watershed analysis suggests future threats from development activities that may include thermal pollution, nutrient loading, sedimentation, and the addition of heavy metals, pesticides, and pathogens to the watershed. The management plan firstly recommends continued monitoring to assess the addition of these threats. The plan also recommends a robust education and outreach program and specific protection measures to avoid these potential problems. To determine specific recommended tasks and actions, the SNRE team utilized GIS to identify priority areas and parcels for protection as well as critical areas—namely the Lower Watershed—for immediate attention. The team also designed an education strategy and outreach materials to be used by the Watershed Council in the future.
Tannery Creek is a small, but important creek to Little Traverse Bay, which is in turn important to Lake Michigan. The SNRE team and the Watershed Council recognize that even the smallest creeks are critical to the health of broader watersheds. Effective stewardship begins on a local community level and the SNRE team hopes that the Tannery Creek Watershed Management Plan will be an important contribution to the Watershed Council’s ongoing efforts to restore and protect the vibrant watersheds of Northern Michigan.
Watershed Analysis. To better understand the current state of Tannery Creek, the SNRE team conducted an assessment of the full watershed utilizing Geographic Information Systems (GIS) and two specific modeling tools, namely Impervious Land Cover and Long Term Hydrologic Impact Assessment (L-THIA). To aid in this analysis, the SNRE team divided the Tannery Creek Watershed into three distinct sub-watersheds: West Branch, East Branch, and the Lower Watershed. The Impervious Land Cover tool evaluates impervious surface percentages and revealed current problems in the Lower Watershed. The L-THIA model estimates runoff, recharge, and nonpoint pollution for a given area. The team used zoning information from the Bear Creek Township Master Plan to create a “build-out” scenario that projects future runoff volumes for the Tannery Creek watershed. Based on this build-out scenario, it is clear that the East Branch and West Branch portions of the watershed may experience negative impacts of runoff in the future due to development pressures and increased impervious surface levels.
Public Outreach. The SNRE team conducted extensive public outreach and education both to inform the stream assessment and watershed analysis described above and to begin the process of achieving buy-in from local residents and businesses for management recommendations. The team conducted a survey of residents and businesses to explore uses and impressions of the creek. In addition to one-on-one conversations with many residents and business owners, the team conducted two Community Forum meetings in March 2013 to further engage those who live and work in the Tannery Creek watershed. iii
Recommendations. Though current threats to Tannery Creek are primarily from debris/litter and altered hydrology, the watershed analysis suggests future threats from development activities that may include thermal pollution, nutrient loading, sedimentation, and the addition of heavy metals, pesticides, and pathogens to the watershed. The management plan firstly recommends continued monitoring to assess the addition of these threats. The plan also recommends a robust education and outreach program and specific protection measures to avoid these potential problems. To determine specific recommended tasks and actions, the SNRE team utilized GIS to identify priority areas and parcels for protection as well as critical areas—namely the Lower Watershed—for immediate attention. The team also designed an education strategy and outreach materials to be used by the Watershed Council in the future.
Tannery Creek is a small, but important creek to Little Traverse Bay, which is in turn important to Lake Michigan. The SNRE team and the Watershed Council recognize that even the smallest creeks are critical to the health of broader watersheds. Effective stewardship begins on a local community level and the SNRE team hopes that the Tannery Creek Watershed Management Plan will be an important contribution to the Watershed Council’s ongoing efforts to restore and protect the vibrant watersheds of Northern Michigan.
