Mitigation Wetlands Study by ODU's Whittecar Is Supported by $250,000 in Funding
When a permit is issued to allow wetlands to be filled for a construction project, the developer is often required by the permitting agency, such as the U.S. Army Corps of Engineers, to create elsewhere a comparable tract called mitigation wetlands. But questions exist about the efficacy of these tradeoffs, and Old Dominion University geologist Richard Whittecar has received a grant to examine reasons why mitigation wetlands sometimes produce disappointing results.
Whittecar is part of a team, which also includes researchers from Virginia Tech, that received $600,000 from the Peterson Family Foundation for a 36-month study on behalf of the Piedmont Wetlands Research Program. ODU's portion of the funding is almost $250,000.
The researchers will assess existing procedures and models for their effectiveness in predicting groundwater and surface water flows in mitigation wetland sites typically constructed in the Virginia Piedmont. The models that prove to be most effective will be packaged as modules and incorporated into a software package that will be easy for wetland developers to use. In addition, the researchers will develop training materials and offer workshops to teach others to use the new software product.
Piedmont Wetlands Research Program is a collaborative initiative of Wetland Studies and Solutions Inc. and state and federal regulatory agencies responsible for wetland protection.
"People build mitigation wetlands to restore valuable ecological functions in a watershed impacted by construction projects. Nearly all of these new wetlands restore some of the lost wetland functions, but sizable parts of many projects end up wetter or drier than planned," explained Whittecar, whose research interests include wetland hydrology.
He said that mitigation wetlands are difficult to design without a thorough understanding of the amount and movement of water that will pass through the mitigation sites, both before and after construction. Existing procedures used to assess the hydrology of a potential wetland site often have significant limitations, he added, if they do not incorporate enough information about groundwater flow through neighboring aquifers and surface water flow across the newly constructed wetlands.
Whittecar's contribution to the project will include a new assessment of data from hydrologic, soil and geologic studies collected by developers of large, existing wetlands in the state's Piedmont region.
"Experiences in wetland construction over the past two decades and scientific advances in addressing hydrologic issues with various models suggest that many improvements are possible in the existing predictive procedures," he said.
Wetlands such as bogs, swamps and marshes are characterized by frequent or prolonged presence of water at or near the soil surface; hydric soils that form under flooded or saturated conditions; and plants that have adapted to live in these types of soils.
When operating efficiently they 1) improve water quality by removing excess nutrients that may come from fertilizers or wastewater and by trapping other pollutants in soil particles; 2) store storm water to reduce flooding; and 3) provide a habitat for plants and wildlife, including more than a third of threatened and endangered species.