Great Lakes Coastal Dynamics and Local Master Planning

The Great Lakes extend 750 miles from east to west and touch some 4,500 linear miles of U.S. shoreline, covering a combined surface area roughly the size of the United Kingdom.(1) As with ocean coasts, the Great Lakes are large enough to generate substantial hazards to shorelands from both ongoing erosion processes and periodic storm events.

Lake Michigan shoreline in Ferrysburg, MI (Cory Morse, MLive.com, October 2019)

However, the Great Lakes are physically and institutionally different from the ocean. Most prominently, the Great Lakes are geologically young features subject to background erosion rates of about 1 to 2 feet per year throughout much of the basin. The Lakes are simultaneously subject to fluctuations in standing lake levels on the order of 1 or 2 meters over the course of decades.(2) With these periodic cycles, Great Lakes shorelines can appear to be retreating lakeward when lake levels are low for an extended period of time, only to move substantially inland as water levels again rise, sometimes from a single storm event. 

While it is unclear how climate change will affect the Great Lakes overall, it will likely increase the frequency and intensity of storms, as well as accelerating how frequently lake levels fluctuate, both of which may lead to more aggressive erosion along much of Michigan’s Great Lakes shorelines.(3) 

Institutionally, the Great Lakes shoreline has a highly fragmented governance structure. Most of the states bordering the Great Lakes—including Michigan—are Northwest Territory states with civil townships, which represent an added layer of local government in between counties and incorporated municipalities.(4) In addition, all of the Great Lakes states apply the Public Trust Doctrine to their Great Lakes shorelands, yielding highly diverse and complex state-local legal and policy institutional arrangements.(5)

Climate change will likely increase the frequency and intensity of storms, as well as accelerating how frequently lake levels fluctuate, both of which may lead to more aggressive erosion along much of Michigan’s Great Lakes shorelines.

The International Joint Commission (IJC) released several reports in the early 1990s that collectively began to document the effects of Great Lakes’ water level variation on shoreline dynamics, the impacts of those dynamics on natural and built resources, and the conflicts and challenges those impacts presented to shoreland area management efforts.(6) Other agencies and authors have since issued similar reports, guidebooks, and “toolkits” designed to outline different shoreland area management strategies, providing generalized discussions of their applicability, strengths, and weaknesses.(7) Nonetheless, beyond these more generalized studies, little research has been conducted to systematically evaluate the acceptance, adoption, and usefulness of those various options in context through actual attempts at implementation.

Purpose of Study

Erosion along Lake Michigan in Park Township, MI poses issues for property owners along Lakeshore Avenue. (Cory Morse, MLive.com, October 2019.

The purpose of this ongoing study is to develop and continually improve methods that can help coastal communities better assess the potential to restore and conserve their dynamic Great Lakes coastal shorelands through local master plans, regulations, and infrastructure policies, as those activities are framed through state shoreland management policies and laws, and then to implement those plans, regulations, and policies.

To that end, this report represents the outcome of recent and ongoing work on Great Lakes coastal habitats and shoreline dynamics designed to establish a set of methods that enable analysis of shoreland dynamics, fiscal impacts, environmental vulnerabilities, visualized high risk areas, and land use impacts. The methods are designed to help communities make planning decisions based on known information about the Great Lakes systems. Researchers from the University of Michigan (UM) and Michigan Technological University (MTU) collaborated with community planners from the Land Information Access Association (LIAA) and program staff from the Michigan Coastal Management Program in order to identify and analyze hazard areas, and then collaborated with local community officials and citizens to incorporate those analyses into plans and policies design to enhance local coastal shoreland management. 

The research team developed this guidance manual by drawing from those applied research efforts conducted collaboratively with several community partners located on Lake Michigan and then ‘published’ it originally on this website in 2015.  Since then, we have continued to apply these methods to analyze conditions and hazard risks for additional communities on the Grand Traverse Bay and on Lakes Huron and St. Clair. Drawing from experience in employing the methods for additional communities and in different settings, we updated the manual in 2020.

This manual describes key approaches, assumptions, and methods that communities can follow to address shoreland management. Communities can follow the same process or tailor it to their own particular interests and needs.

Our goal is to encourage other coastal communities to explore and apply these methods and ideas on their own, thereby helping those communities become more adaptive and resilient given the impacts of ongoing coastal dynamics along their coastlines.

Citations:

1. EPA (U.S. Environmental Protection Agency). 2014. The Great Lakes: An Environmental Atlas and Resource Book. http://epa. gov/greatlakes/atlas/index.html. GLERL (U.S. Great Lakes Environmental Research Laboratory). 2014. About Our Great Lakes: Great Lakes Basin Facts. http:// www.glerl.noaa.gov/pr/ ourlakes/facts.html. MDEQ (Michigan Department of Environmental Quality). 2014. Shorelines of the Great Lakes. http://www.michigan. gov/deq/0,4561,7-135- 3313_3677-15959–,00.html  

2. Norton, Richard K. and Guy A. Meadows. 2014. Land and water governance on the shores of the Laurentian Great Lakes. Water International 39(6):901-920.

3. See reports, fact sheets, and other resources available at: Great Lakes Integrated Sciences Assessments. http://glisa.umich.edu/.

4. Norton, Richard K. , Meadows, Lorelle A. and Meadows, Guy A.(2011) ‘Drawing Lines in Law Books and on Sandy Beaches: Marking Ordinary High Water on Michigan’s Great Lakes Shorelines under the Public Trust Doctrine’, Coastal Management, 39: 2, 133 — 157, First published on: 19 February 2011 (iFirst)

5. Norton, Richard K., Guy A. Meadows, and Lorelle A. Meadows. 2013. The deceptively complicated ‘elevation ordinary high water mark’ and the problem with using it on a Great Lakes shore. Journal of Great Lakes Research 39(2013):527-535.

6. International Joint Commission. 1993. Lake Levels Reference Study: Great Lakes-St. Lawrence River Basin, Annex 2 (Land Use and Management). Working Committee 2 Final Report submitted to the Levels Reference Study Board, March 31, 1993. ISBN 1- 895085-46-2. 

7. US Army Corps of Engineers, Detroit District, and Great Lakes Commission. 1999. Living with the Lakes: Understanding and Adapting to Great Lakes Water Level Change. ISBN 0-9676123-0-6. Ardizone, Katherine A., and Mark A. Wyckoff. 2010. Filling the Gaps: Environmental Protection Options for Local Governments (2nd ed.). Lansing, MI: Michigan Department of Natural Resources and Environment.