Bridging the Environment

Bridging the Environment

New wetlands projects will be evident in springtime.

Come spring, some of the good things of the Woodrow Wilson Bridge Project will be evident for all to see and enjoy. Two wetlands projects have been completed ahead of schedule.

A 2.2 acre area at Four Mile Run Park, just west of the Reagan Washington National Airport, and a 3.5 acre site along Neabsco Creek, just south of Woodbridge, will both bring forth an array of flora and fauna with the warming weather. Both came in "on-budget," according to project management.

Alexandria's $1.09 million project is designed to protect, enhance and create wetland and riparian habitat along two tidal tributaries to Four Mile Run. It is predicted to also improve water quality through the creation of forested stream buffers and the restoration of approximately 500 linear feet of eroded stream banks, according to Ronoldo "Nick" Nicholson, bridge project manager, Virginia Department of transportation.

The Woodbridge site, known as the Hart Property, turned a 3.5 acre dumpsite into wetlands, reconnecting Neabsco Creek to its soon-to-be forested floodplain. Both projects were undertaken "to compensate for unavoidable aquatic resource losses associated with construction of the bridge," Nickolson explained.

"Our strong partnership with the City of Alexandria and local residents is a key reason why the Four Mile Run project has been so successful. From groundbreaking to our teaming up for Earth Day activities to the job's conclusion, the city's spirit of collaboration has been instrumental at every turn," Nickolson said.

AT FOUR MILE RUN, nearly 60 species, totaling more than 22,200 native marsh plantings were put in. Many of those flowered in the fall of 2003. The newly forested buffer surrounding the stream will filter nutrients, sediment and other pollutants.

In order to better enjoy the new site, many park amenities requested by Alexandria were added to the design plans. These include park benches, interpretive signs, landscaping, and a stone tidal marker to assist school programs and park users, according to John Undeland, director, Woodrow Wilson Bridge Project Public Affairs. "They will be installed in the near future," he said.

Because the Four Mile Run wetlands was created to replace tidal wetlands lost around the new bridge, the designs were required to allow tides to alternately flood and expose the land surface at least twice daily. Surface elevations were designed to be between mean high and mean low tides.

At Hart, non-tidal wetlands were created by grading the area to an elevation that would allow high flows from Neabsco Creek to periodically flood the site. This wetland will provide wildlife habitat, flood storage and nutrient retention capabilities to the creek's drainage while adding significant protected landholdings, according to engineers.

Undeland noted, "The project has demonstrated its commitment to the environment by investing more than $50 million in environmental initiatives." It involves not only wetlands creation but also river grass plantation, reforestation, stream restoration and habitat preservation.

The project's "green program" extends more than 50 miles south, 30 miles west, and 20 miles north and east of the bridge. It is estimated the project's mitigation program will preserve or enhance more than 130 acres of wetlands in Virginia and Maryland.

Other environmental efforts include fish passage restoration, an 84 acre bald eagle sanctuary and the largest blue heron rookery on the east coast.