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September/October 2014 | 5 P erhaps you'll never guess what was responsible for the creation of the largest non-tidal wetland in northern Virginia. The answer? Beavers. That's right, when beavers arrived to the area in the late 1970s, damming activities created a swamp/flooded forest that contributed to the birth of Huntley Meadows Park, now comprising 1,500 acres in Alexandria. That system later transitioned into a hemi-marsh, an ecosystem that contains one of the highest levels of biodiversity and ecological function. But over time, consecutive droughts, beaver activities and other natural factors, in addition to the deposition of silt and debris from upstream development, deteriorated the wetland. Invasive species took over as a result of shallow water levels, which greatly reduced the diversity of wildlife habitat. In 2011, Wetlands Studies and Solutions, Inc. (WSSI), was selected to develop an environmentally sensitive design that would meet all of the project goals and be permittable by state and local regulatory agencies. The Fairfax County Park Authority (FCPA) contracted WSSI to restore the central wetland area and revive its operation as a hemi-marsh system containing roughly 50 percent open water and 50 percent vegetated wetland in winter, with a summer draw down capability. Not only would the restored wetland provide habitat for target plant and animal species that existed in the original hemi-marsh, but it would also provide habitat variation, with annual forage restoration for a variety of animal species. Creating and maintaining the hemi-marsh condition at Huntley Meadows, however, was easier said than done. But the efficient teamwork and innovative ideas WSSI delivered throughout the project ultimately produced a design FCPA staff and skeptical citizen activist groups approved. FINDING THE RIGHT SOLUTION. The purpose of the Huntley Meadows Restoration project? To restore the central wetland area at the park to enhance its habitat and improve ecological functions and values. Based on FCPA records, Huntley Meadows receives approxi- mately 200,000 visitors and conducts more than 400 programs with 10,000 students each year. WSSI faced a significant engineering challenge when construction began in April 2013: to raise the permanent water surface elevation higher than its current elevation, as well as vary it over time, by designing a water control structure that would blend into the park environment. To accomplish this, the team developed the following five components of the project: 1. a water control structure to detain inflows while providing an overflow for larger storm events; 2. an outlet structure to manage flow from smaller storms and to enable FCPA staff to seasonally adjust water levels; 3. expansion of the wetland into the surrounding forest; 4. five deeper habitat pools to provide year-round aquatic wildlife habitat; and 5. numerous brush shelters and basking logs to provide additional wildlife habitat. ENSURING A LASTING IMPRESSION. After more than 30 total years of planning, public meetings, and a cutting-edge design and construction process, WSSI executed the right solution to restoring Huntley Meadows for FCPA. The team went above and beyond the scope and requirements of the project contract, contributing nearly 400 hours of pro bono time, free materials and staff training. Park staff and volunteers will continue to monitor, manage and maintain the wetland. Coupled with the success achieved through the prescribed manipulation of the water surface elevation and resulting improvement in the health and diversity of the central wetland area, the engineered solution will provide an example for future environmental projects. RECEIVING RECOGNITION. WSSI's resto- ration design was so well-received, the project team and its efforts earned much recognition. The Fairfax County Park Foundation awarded Mike Rolband, vice president of operations, WSSI, the 2014 Eakin Philanthropy Award for his team's skillful work on the Wetland Restoration project at Huntley Meadows. The team also received the National Recognition Award in the 2014 Engineering Excellence Awards competition from the American Council of Engineering Companies (ACEC). Other project awards include: an Honor Award in the Water Resources category, from ACEC Metropolitan Washington; the 2013 Fairfax County Tree Preservation Award; and the 2013 Fairfax County Land Conservation Award for the Best Protected Environmental Site. WSSI helps revive Huntley Meadows Park to create a thriving hemi-marsh environment. Habitat Pool A, completed. WSSI installs Clemson Beaver Pond levelers in Habitat Pool D for the restoration of the wetlands. Huntley Meadows undergoes the installation of a water control structure.

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