Wetlands Mitigation Data Report for Federal-Aid Highway Projects
Fiscal Year 2000

Background

An indicator of meeting the FHWA Strategic Plan objective for protecting the natural environment is to provide compensatory mitigation on Federal-aid highway projects that results in a net increase of a wetland acreage of at least 50% over a ten year period from 1996 to 2006. Documenting agency performance toward achieving this program-based indicator is achieved by obtaining information from State Departments of Transportation and FHWA field offices that allows a comparison of the area of wetlands unavoidably impacted to the area of compensatory wetland mitigation provided. The most direct and straight-forward way to gather and present the information is on an acreage basis.

As a result, progress during Fiscal Years 1996-1999, and now, 2000 has been measured for Federal-aid projects nationwide by comparing the total acres of wetland impacted by projects in the reporting State programs to the acres of compensatory wetland mitigation. Over this short period of time, we believe the data provides a valuable performance indicator of the Federal-aid highway program in achieving an immediate increase of wetland area, and strongly indicates that a long-term net gain of wetlands functions and values can be realized within the Federally funded highway program. However, we caution against drawing conclusions at this early stage concerning replacement of wetland functions and values, long-term mitigation success, ecological effectiveness, and other similar measures which would be required for a complete assessment of a sustained net gain in wetlands area, functions, and performance. Furthermore, we continue to recommend that further research on the success and performance of compensatory mitigation sites is necessary to substantiate the achievement of our long range strategic performance objectives.

Results for Fiscal Year 2000

Forty-six States, Puerto Rico and the District of Columbia reported data for Fiscal Year 2000. A total of 1878 acres of wetland loss, and 7057 acres of compensatory of mitigation were reported. On a program-wide basis, the Fiscal Year 2000 figures indicate that Federal-aid highway projects on average provided 3.8 acres of compensatory wetland mitigation for each acre of impact. Using the reported data, we estimate that impacts to wetlands for the total Federal-aid highway program was approximately 2041 acres, and that the program provided 7671 acres of compensatory mitigation. The estimates for all 50 States, Puerto Rico, and the District were made using the data from the 47 reports received divided by the fraction of total possible reports possible that were actually received: 47/51 = 0.92 (Note: data from the District and Puerto Rico were combined, due to the small area involved). Although the data do not provide a complete record of wetland impacts due to all Federally funded highway projects, we feel the 92% sample provides a good measure of overall Federal-aid program performance against the "net gain of wetlands" objective.

These results also indicate the magnitude of the highway program's contribution to overall nationwide wetland impacts and mitigation. Compared to wetland losses and compensation nationwide, the FY 2000 data for the Federal-aid highway program indicate that highway impacts and mitigation represent a relatively small percentage of the national total due to all activities. Federal-aid highway projects account for approximately 2 percent of the loss rate, and about 3 percent of the gain rate. These estimates are based on our interpretation of information available from the U.S. Fish and Wildlife Service National Wetlands Inventory and U.S. Department of Agriculture (USDA) National Resource Inventory.

Summary

The reports submitted indicate that the Fiscal Year 2000 compensatory mitigation ratio is approximately 3.8:1 for the Federal-aid highway program on a national basis. This ratio is a substantial increase compared to wetlands impact and mitigation data for the Federal-aid program collected in Fiscal Years 1996-99.

The mitigation ratio reflected in these data are a strong indication that the project eligibility and funding provisions for wetland mitigation in the Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA) and strengthened in TEA-21, continue to be effective in enhancing the natural environment. We feel that those provisions will be helpful in accomplishing the Nation's environmental goals under the Clean Water Action Plan initiatives and the National Wetlands Plan. We also believe these data indicate use of the increased flexibility for mitigating wetland impacts through other wetland conservation programs which are eligible for TEA-21 funds. This could yield further cost efficiencies and ecological benefits in mitigating the wetland impacts of highway projects.

Geographic Distribution of Mitigation Data

The following table provides a summary analysis of reported wetland impact and mitigation acreage by geographic area:

Comments on the geographic distribution of compensatory mitigation

The exceptionally high mitigation ratio in the southeast is due to large mitigation projects in Georgia, Florida, South Carolina, and North Carolina, resulting in a reported total area for compensatory mitigation in these four states of 5378 acres for Fiscal Year 2000. This represents 70 percent of the estimated total mitigation area reported for the Federal-aid program nationally. The large areas reported as compensatory mitigation by these states represents several large wetland/upland complexes and mitigation banks based on preservation of locally and regionally significant wetlands, as well as restoration and creation of wetlands. These four States also had a combined impact area of 839.5 acres, resulting in a combined mitigation ratio of 6:1 for the Fiscal Year.

It is difficult to detect or identify distinct trends in mitigation ratios between areas based on this geographic breakdown, other than for the four southeastern States mentioned. Other reporting States in the Southeast had a combined mitigation ratio of 1.8:1, which is the same as the adjusted national average (ignoring GA, FL, SC, and NC). The mitigation ratios in the other geographical areas ranged from 1.3:1 to 2.2:1.

Alaska is unique in that much of the State is either jurisdictional wetland, aquatic, or montane environments. The shortage of land available for development in Alaska creates a situation in which mitigation for highway project impacts on typical wetlands is more dependent on the specific resource being affected than the area. Fisheries and wildlife functions are of the most concern in Alaska, and out-of-kind mitigation to enhance these resources is common, resulting in low ratios by area, but valuable replacement of functions, nevertheless.

Five-Year Data and Performance Summary

As a measure of performance under the FHWA's net gain policy, the agency has monitored annual wetland loss and gain under the Federal-aid highway program nationwide. Monitoring began in Fiscal Year 1996. Our data collected over the last 5 years indicate that nationwide, the Federal-aid highway program has achieved an average annual gain of 170% in wetland acreage (2.7:1 gain/loss ratio). In terms of actual acres, the Federal-aid highway program has produced a reported total net gain of 14,846 acres of wetlands nationwide 1996 through 2000.