II. Giving the Shoreline Space to Move
A. What it is and why it supports coastal resilience
The key thing to remember about the natural systems along Great Lakes shorelines is that they are dynamic, meaning they are constantly changing. Although specific shoreline conditions change between seasons and years, the results of these changes are fairly predictable: at some point, shoreline buildings and infrastructure will experience erosion, flooding, wind, and wave damage.
The pressure to build along the privately owned lake edge, which accounts for about 80% of Michigan’s coastal shoreline, brings the built systems into conflict with the natural systems. Because of the shoreline’s dynamic and forceful nature, the tools for managing land use along the shoreline call for giving the shoreline space to move, rather than responding by armoring the shoreline to keep it in place, which is doomed to fail over the long term.
This section highlights some resources that communities can use to learn about the unique characteristics of their shoreline, including how much room the lake needs to give it space to move in the future.
| How Has Erosion Affected Your Shoreline? Try Michigan Tech University's Interactive Coastal Viewer Click above and select Lake Michigan & Lake Huron Shorelines or Lake Superior Shorelines |
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| Lake Huron (Near Thunder Bay River State Forest, Alpena County) | Lake Superior (Near Picnic Rocks, Marquette County) |
| Note: Numbers on the thick colored line indicate the long-term rate-of-change in meters/year (1938-2020) | |
B. Why isn’t this already done?
The short answer is: existing and potential economic value.
Because we love the water, we’ve already built things next to it. Those things are valuable because of the investment, and often they are even more valuable because they are next to the water. Even where we haven’t built anything yet, we know from past experience that it would be valuable if we did. It’s legally and politically tricky for regulation to interfere with economic value.
Especially in the case of existing investment, this is a compelling argument for doing nothing. Legal restrictions risk legal challenges. Individuals and communities alike are susceptible to defeatism, the idea that it is too difficult to change what already exists, when they feel that solutions are overwhelming or impractical. Yet a failure to act risks escalating costs and damages down the road, making it even harder to address issues and emergencies. It is a difficult tradeoff to quantify, and the competing interests are fierce.
Developing and adopting fair, thoughtful land use policy and regulation is a slow and challenging process, but the very foundation of land use management is to evenhandedly impose such regulations as are necessary to safeguard public health, safety, and welfare. A conscious shift toward a forward-thinking and solution-oriented mindset can help reframe the concept of “value” to better reflect these fundamental public benefits.
C. How much space does the lake need?
The first question to consider when contemplating regulations that allow the shoreline space for its natural processes is: How much space does the lake need? This understanding will inform the type of regulation implemented as well as the specific distance from the water’s edge that will provide an appropriate amount of protection for the built environment.
The Michigan Resilient Coastal Communities Planning Guide 4, created by the Michigan Coastal Management Program, provides a comprehensive description of the natural coastal processes that communities experience. For coastal communities to effectively plan for coastal hazards, it’s important to start by assessing the conditions that are unique to their coastline. The Guide identifies a number of online tools and data sources that communities can access for this information free of charge, some of which are highlighted here.
Great Lakes Water Levels
A recurring shoreline management problem is the temptation to build near the water’s edge when levels are low, only to have the investment threatened when levels swing back up again. Unfortunately, there is no long-term predictive tool for Great Lakes water levels. The National Oceanic and Atmospheric Association’s Operational Forecast System5 and the US Army Corps of Engineers’ Water Level Forecasts6 can venture only days or months into the future. However, the tools below can guide planning efforts by showing the range of lake level variation in the past.
- The Great Lakes Lake Level Viewer7 is an easy-to-use tool for visualizing potential coastal flooding through a range of water levels. The model is based on calm conditions, so it doesn’t account for storms that would increase water levels or wave impacts. However, the tool can serve as a discussion-starter and inform planning for sections of the coast prone to flooding.
- For an overview of the historical and natural processes at play in Great Lakes water level variation, explore NOAA’s Water Levels in the Great Lakes StoryMap8.
Coastal Flooding
Flood maps show how likely it is for an area to become inundated with water. Any place with a 1% chance or higher chance of experiencing a flood each year is considered to have a high risk. These maps can be used as visual tools to educate property owners about their flood risks and help local officials make decisions about capital improvements and future land use planning. Official flood maps may be found at the Federal Emergency Management Agency (FEMA) Flood Map Service Center9. An Introduction to FEMA Coastal Floodplain Mapping10 provides additional information unique to coastal flooding.
Coastal Erosion
Unlike water levels, which reach toward land and then recede, erosion is on a consistent landward march. Since the characteristics of the land play a determining factor in whether and how shoreline erosion occurs, knowing where it has occurred in the past can help predict where it may occur in the future.
One helpful resource is Michigan Coastlines Through Time11, created by Michigan Technological University for EGLE. This web-based viewer allows users to view and compare aerial photography of shoreline and bluff line locations collected at intervals over the past 80 years. While this tool does not predict where the shoreline will be in the future, it can powerfully illustrate to the community where the coastline could be.
Portions of the Michigan shoreline identified as High Risk Erosion Areas (HREAs)12, Critical Dune Areas13, or Environmental Areas (EAs)14 are regulated by the state of Michigan. Permits are required for construction in these areas. Local units of government may adopt a zoning ordinance to administer permits for state-designated lands within their municipality.
5 NOAA. https://tidesandcurrents.noaa.gov/models.html
6 US Army Corps of Engineers. https://www.lrd.usace.army.mil/Water-Information/Water-Management/Great-Lakes-and-Harbors/Water-Level-Forecasts
7 NOAA. https://coast.noaa.gov/llv/
8 NOAA. https://storymaps.arcgis.com/stories/f60be9e50c6341d6b76e62f84de43dd6
9 FEMA. https://msc.fema.gov/portal/home
10 FEMA. https://fema.maps.arcgis.com/apps/MapSeries/index.html?appid=89d2e393f2c64d7cae07264f4d00c19d
11 EGLE, https://portal1-geo.sabu.mtu.edu/mtuarcgis/apps/sites/#/czmp
12 EGLE. https://gis-egle.hub.arcgis.com/datasets/egle::high-risk-erosion-zones/explore
13 EGLE, https://www.michigan.gov/egle/about/organization/water-resources/sand-dunes/critical-dunes/maps
14 EGLE, https://gis-egle.hub.arcgis.com/datasets/egle::environmental-areas/about
| Tools to Better Understand Your Community Click to visit the page |
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| Great Lakes Level Viewer (NOAA) | Water Levels in the Great Lakes StoryMap (NOAA) | Michigan's Coastlines Through Time Viewer (NOAA) | High-Risk Erosion Area Maps (EGLE) |
| Flood Map Service Center (FEMA) | Environmental Maps and Open Data (EGLE) | Wetlands Map Viewer (EGLE) | |
