Wakefield Park Trails
The tenants of conservation aren't only relevant to backcountry settings, they also guide mountain bike trail design in urban environments. Wakefield Park, just outside of Washington D.C., is sandwiched between the bustling Capital Beltway and the natural beauty of the Accotink Creek - a beauty that was recently threatened by massive amounts of sediment releases from power line access roads and poorly designed trails. IMBA Trail Solutions was hired to address the complicated environmental issues affecting the park while creating a fun and sustainable trail system.
"Poor drainage was a huge issue," noted Rich Edwards, IMBA Trail Solutions Manager. The tower foundations created channels of water that carved gullies into the dirt roads and dropped straight into the creek below. "When it rained, it looked like water hoses were attached to the frames of the towers," observed Edwards. Because the power line easements could not be blocked, re-vegetated, or moved, Trail Solutions needed to come up with creative trail design and active drainage solutions.
The magnitude of water flowing into the creek required a variety of solutions to be implemented simultaneously. Several grade reversals, or dips in the terrain, were built to de-channelize and mitigate the erosive water flowing from the towers. Edwards also designed vernal pools to collect the water before it reached the creek. In an effort to restore some of the natural habitat to the area, frog eggs and organic material were transplanted into these water basins.
A full trail redesign plan was developed with the objectives of rerouting fall line trails, protecting environmentally and historically sensitive areas, and providing an enjoyable natural user experience for millions of nearby residents. Since most of the parkland available for trail development was on power line easements, floodplain, or in areas where paleontological relics might be found, designing suitable reroutes became a very complex task.
Several boardwalks were created to traverse the floodplains and the drainage of the plain areas was enhanced to create a good habitat for amphibians. Many trails ran straight down the power line easements, creating an erosion nightmare and a very poor user experience. The rerouted trails were designed to be sustainable, fun, and hydrologically invisible.
Special consideration was taken to bring the trails through, and consequently destroy, invasive species where possible. The rehabilitated areas were carefully replanted with not only native species, but with seeds that matched the genotype of the area.
When trails that ran straight down the access roads could not be rerouted due to land constraints, Trail Solutions developed a solution that blended science with creative trail design. Large berms and grade reversals were built all the way down the power line cut in such a way that service vehicles could still utilize the route. The berms changed the alignment of the trails, significantly improving the riders' user-experiences while minimizing erosion by keeping riders from following fall line.
The Wakefield Park project has resulted in a significant improvement to the park's environment and a major reduction of the sediment reaching Accotink Creek. It's also hailed as one of the most poplar and best trail systems in the DC Metro area.
It is especially important to take environment impacts and restoration into consideration in urban parks, as they are often the only access to a natural environment for millions of people. While mountain bikers and trail users directly benefit from IMBA's work at Wakefield Park, the actions taken to protect and enhance the park's environment resonate throughout the entire community.
This report was made possible by a grant from Shimano.