Wetlands Research Initiative

The primary mission of the Wetlands Research Initiative (WRI) is to fund applied research that can make a real and measurable difference in wetland creation, restoration, and enhancement activities in the Virginia Piedmont. Our results are also applicable to a wider range of wetland systems throughout the mid-Atlantic region. The WRI supports projects asking important questions about the overall effectiveness of compensatory wetland impact mitigation efforts, and specifically how design and construction practices should be modified to improve compensatory mitigation efforts with respect to created wetland functions and values.

Documents pertaining to each research topic are available on the individual research pages.

Wetland Hydrology Monitoring

This research project was primarily conducted by Virginia Tech and focused on answering a very basic question that practitioners and regulators had seen in the field in clayey soils: Are commonly used shallow groundwater monitoring wells accurately capturing the actual groundwater elevation (and/or ponding) in wetlands, particularly because of the presumed “response lag time” in clayey materials? Secondary questions included which type of monitoring well design performed the best and what was the spatial variability of well response in the field. A parallel study focused on developing an improved automated water level monitoring system, and was conducted by Christopher Newport University.

Water Budget Modeling and Monitoring

This combined area has been our largest research investment over time and has been active for over ten years. The long-term project (10+ years) has been collaborative between Virginia Tech, Old Dominion University and the University of Kentucky. The program was originally motivated by numerous agency reports and scientific articles that indicated that the primary reason created wetland compensatory mitigation projects had failed to meet regulatory requirements was primarily related to their failure to achieve the timing, depth and duration of water (e.g. the “hydroperiod”) necessary to support the desired wetlands type(s). The primary goal of this research effort is to develop a user-friendly PC-based water budget model that can model a range of non-tidal wetland types including depressional basins, interconnected cells, and sloping wetlands. The model(s) need to account for both groundwater and surface water driven hydrologic conditions, calculate PET, and provide a statistically based system for selecting appropriate rainfall data for use in the model. Funded has included a wide range of field model calibration/testing sites including local and state parks and mitigation bank sites.

An additional area of active investigation is the development of a library of “target hydroperiods” for commonly restored wetlands system types when reference data is not available to utilize with the water budget model to inform initial site design decisions. These target hydroperiods are based on a wide range of data sets from relatively undisturbed wetland systems in the region including mineral flats, riparian wetlands and Carolina bays and will include an expected range of water levels under dry, normal and wet year conditions.

The primary output of this effort to date has been the development of the Wetbud program, which is available in two versions. The Basic Model assumes a flat basin type system and includes a “Wizard” module with preset defaults that can run a simple model in less than 10 minutes. The Advanced Model requires more input effort and data, but models a much wider range of complex wetland systems including sloping sites.

Sustainable Created Forested Wetlands

Practitioners, the public, and regulatory agencies are concerned with the assurance of successful type-for-type forested wetland creation (or restoration) as compensatory mitigation for forested wetland impacts. The ability of a forested wetland to provide essential functions and values is strongly correlated with the quality/quantity/species diversity of the vegetation. So the overarching question to answer for this research effort was the determination of the best metric(s) to measure the ecological success of forested wetlands restoration.

Related questions include how does the choice of quality (or size)/ quantity/species diversity of woody species affect the ability of the created wetland to perform these functions and how do these functions change through time from initial planting to closed canopy cover? Since wetland mitigation is based on performance criteria, what is the ‘best recipe’ for establishing and ensuring a successfully created sustainable forested wetland in the Piedmont Region of Virginia? Finally, this project is looking at how the plant community can best be be designed and managed in order to provide the greatest diversity and quality of wetland functions and values (wildlife habitat, flood flow attenuation, nutrient uptake, sediment detention, etc.).

This research team, composed of faculty from the College of William & Mary (VIMS) and Christopher Newport University has developed a new metric for forested vegetation success that has been accepted by the Norfolk District of the U.S. Army Corps of Engineers and the Virginia Department of Environmental Quality. A follow-up research award is using the data from this program to help develop a protocol for the most effective selection of species, stocktypes, and densities to meet the recommended state and federal agency success criteria.

Small Grant Program

The purpose of this grant program was to stimulate a series of small research projects suitable for undergraduate level students and a limited number of M.S. level students. This led to a wide range of varied research programs at Duke University, George Mason University, Old Dominion University, Virginia Tech and the College of William & Mary/VIMS. Many of these projects have resulted in larger research awards.

Invasive Species Research in Compensatory Mitigation

One of the most important and pervasive contemporary issues in the field of ecological restoration is that of biological invasion, particularly by non-native species. Current performance standards for invasive species in compensatory mitigation often necessitate the use of targeted (or even broadcast) herbicides, a practice that introduces synthetic chemicals into natural systems and can result in collateral damage to desirable species. The purpose of this RFP is to stimulate scientific investigation that will fill these important research gaps, with a focus on compensatory mitigation sites in Virginia. This work is being conducted by the College of William & Mary.

The overall goal is to provide standards and practices that can be utilized in Mitigation Banking Instruments for invasive species control in terms of:

  1. Specific treatments
  2. Seeding methods
  3. Planting protocols
  4. Monitoring and maintenance

The standards should be practicable and be implementable by bank sponsors and individual mitigation site permittees.

Total Phosphorus, Total Nitrogen, and Total Suspended Solids in Runoff

One function provided by wetlands systems, as well as by other Stormwater Management/Best Management Practices (SWM/BMPs), is improved water quality through treatment of stormwater runoff. Nitrogen (N), phosphorus (P) and sediments are typically the primary pollutants of concern, although a range of organics, metals and salts also pose issues in certain heavy urbanized/industrial areas. Typically, the effectiveness of this water treatment function is evaluated by determining the pollutant load reduction from flow through the wetland/stream and/or BMP system. The first element of this calculation is the estimation of pollutant loading, which typically is [i.e. Virginia Runoff Reduction Method (VRRM)] accomplished using the Event Mean Concentration (EMC) of the subject pollutant which is currently set at 0.26 mg/L of total-P (TP) in Virginia. This value has been unchanged since its derivation from the 1980-81 Nationwide Urban Runoff Program (NURP) study.

The basic issue and associated research question here is whether or not the combination of Clean Air Act implementation and a state law restricting the use of phosphorus lawn fertilizer has reduced the EMC of TP in stormwater runoff in Virginia. The program is also addressing TN and sediment losses in the monitored systems. This project is being conducted by Virginia Tech.

Tree Species/Stock Type Selection

This work is the follow-up to the results from the Sustainable Created Forested Wetlands project, and is being conducted by the College of William and Mary. Using the data from that research program, its goal is to develop a protocol for the most effective selection of species, stocktypes, and densities to meet the recommended success criteria.