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Environmental Review Toolkit


Exemplary Ecosystem Initiatives — 2010

Ohio: PER-93 Wetland Mitigation Area, Perry County Ohio

Photograph of wetland vegetation diversity

Vegetation diversity in the wetland achieved
the highest category of wetland.
Source: ODOT

The Ohio Department of Transportation (ODOT) is responsible for a wetland mitigation project between the old roadway location and the new alignment for State Route 93 in Bearship Township, Perry County. New construction of the roadway impacted 0.47 acres of existing wetlands and mitigation ratio requirements involved the construction of 0.96 acres of new wetland area. ODOT's design for the wetland mitigation project provides for both temporary and seasonal saturation.

Aerial photograph of wetland mitigation

Wetland mitigation on aerial photography
Source: ODOT

The wetland's topography consists of small mounds that create a range of shallow to deeper habitats. This topography variation or “micro-topography” helps support a variety of plant species. Water runoff flows from the surrounding 13 acre into the wetland area. In 2006, the wetland site was planted with 140 woody plants including elder, willow, and ash. As part of the maintenance plan, the site was planted again in 2007 and 2008 with several additional plant species including several varieties of alder, birch, dogwood, elderberry, maple, and mallow. The wetland vegetation includes 99 established species with several dominant species such as rice cut grass, rush, and willow.

View of the mitigation area during construction in May 2006

View of the mitigation area during construction
in May 2006. The microtopography is provided
by the low mounds.
Source: ODOT

ODOT biologists used the Vegetation Index of Biotic Integrity (VIBI) during the first three years after construction of the wetland to survey the quality of the vegetation. The vegetation has been very successful within the wetland area. The wetland is classified as mixed emergent marsh, surface water depression. Applying the 2009 VIBI indicates that the mitigation area is a category 3 superior wetland habitat designation. This categorization is outlined by the Ohio Environmental Protection Agency.

Wetland Mitigation Area

Wetland Mitigation Area
Source: ODOT

The wetland's vegetation diversity, high wetland rating, and the speed at which the wetland received the highest category of wetland recognized in Ohio serves as an example for other wetland mitigation projects in the future. ODOT's ongoing maintenance and careful monitoring help to ensure the success of vegetation and habitat.

For more information, contact Chris Yoder, ODOT at or Matt Perlik, ODOT at