Coastal Hazards Planning Guidance for Indiana Coastal Communities
Developed under Indiana’s Lake Michigan Coastal Program, Coastal Hazards Planning Guidance for Indiana Coastal Communities provides information for local governments about coastal hazards and planning techniques. The report describes various coastal hazards for the Great Lakes and the state of hazard planning for each of Indiana’s shoreline communities. The guide also reviews many coastal hazard model ordinance provisions, and steps to developing new ordinances from these models.
According to the report, the Great Lakes’ lake levels fluctuate naturally and affect the extent of coastal flooding during storms, shoreline erosion and shoreline property damage, wetland acreage, accessibility of public access sites, and depth of navigation channels. There is a difference of 6.30 feet between the highest and lowest water-level elevation in Lake Michigan’s recorded history, which began in 1860. Coastal hazards are considered natural phenomena - that are becoming increasingly more impactful to Great Lakes’ shoreline communities.
The report details the types of coastal hazards that affect the Great Lakes which are categorized by:
- Wave Dynamics - breaking waves, storm surge, *seiche;
- Beach Dynamics - erosion, high erosion hazard areas, accretion, beach nourishment; and
- Beach Structures - parallel, perpendicular, geomorphic engineering, setbacks.
(A *seiche is a standing wave that oscillates in a lake as a result of strong winds and changes in atmospheric pressure that push water from one end of the lake to the other, creating huge overall changes in water levels.)
Thirteen Indiana municipalities border Lake Michigan, as well as Indiana Dunes National Lakeshore and Indiana Dunes State Park. Each community is profiled for its coastal hazards, along with a localized map that indicates levels of erosion and accretion, natural and enhanced shoreline features, and infrastructure in the coastal zone.
Section IV: Suggested Hazards Ordinances contains model ordinances that can be adopted by municipalities to address some of the risk and impacts associated with coastal hazards. This section describes ordinance provisions for:
- overlay zones,
- coastal hazard setback,
- shoreline protection structures,
- disclosure of coastal hazards,
- shoreline vegetation buffering, and
- site planning.
The report also shares techniques on how to approach composing a coastal ordinance by reviewing the essential elements of: Purpose and Intent, Applicability, and Definitions sections. There are several options for where to include coastal hazard ordinances: in existing zoning ordinances as a special provision for shoreline areas, in a newly created coastal protection overlay zone, or in an existing subdivision ordinance.
The Lake Michigan Coastal Program (LMCP) supports coordination and partnerships among local, state and federal agencies, and local organizations to protect and sustainably use natural and cultural resources in the Lake Michigan region. The LMCP offers technical assistance to shoreline communities wanting to meet the concurrent, sometimes competing, goals of preservation, protection, conservation and development of the Indiana coastal region.
Publication Date: July 2016
- Indiana Lake Michigan Coastal Program
- Indiana Department of Natural Resources
- Planning guides