Tuesday, April 24, 2012
A project to realign the flow of a section of Charlottesville’s
is scheduled to begin later this spring after six years of planning.
“We’re on the cusp of making this a reality,”
, the director of Charlottesville’s Parks and Recreation Department, said at a public meeting on the subject Monday at
Charlottesville High School
Click to enlarge this map depicting the scope of the restoration project (Source: City of Charlottesville)
stream restoration project is funded by $3.95 million from the Virginia Aquatic Resources Trust Fund. That organization is a joint project of the
and the U.S. Army Corps of Engineers.
In total, 9,000 linear feet of Meadow Creek’s stream bank will be restored between
Park, preserving 10 acres of wetlands.
is a tributary of the
, which is listed by the Virginia Department of Environmental Quality as impaired because of excessive sedimentation.
The waterway’s watershed has been severely affected by the gradual conversion of agricultural land to commercial development as
was transformed over many decades. Rain that falls on the impervious parking lots means that stormwater runs rapidly into the watershed, carrying increased sediment with it.
“There’s been quite a bit of excess sediment, which causes problems for fish and any bottom-dwelling creatures which serve as the base of the food chain,” said Diane Frisbee of the Nature Conservancy. “The whole system is in a state of instability.”
A sample of the current conditions of Meadow Creek
Daly said current conditions of the stream feature trees downed by intense floods and tall banks with exposed dirt.
“The goal is to realign the stream channel to align it with the flood plain,” Daly said.
Engineers with the firm VHB developed the plans by calculating how a natural channel would work. This was accomplished by surveying the existing stream, taking an inventory of the trees and finding out where wetlands exist.
“The idea with the approach we have taken is to apply geomorphology principles… to understand the watershed that contributes to Meadow Creek and create a new channel configuration that is effective in dissipating energy,” said VHB engineer Neville Reynolds.
Reynolds said in many places the channel is too deep, which means water moves too fast after storms.
“The velocity comes up and rips the channel apart,” Reynolds said.
As part of the construction, elements will be placed to slow the channel down so it can better handle the volumes that flow through it following heavy rainfall. This will involve reducing the heights of banks in some places, creating places for the stream to meander slowly and replanting trees to create wider riparian buffers.
A VHB rendering of what the above section of stream could look like after restoration
Frisbee said the goal of the entire project is to create a healthy ecosystem.
“We are going to take away the unstable banks that are causing trouble for the stream,” Frisbee said.
Another part of the project is to remove invasive species. These include the Norway Maple, Chinese silvergrass and golden bamboo.
Reynolds said the invasive species will be removed over the summer by crews certified to spray pesticides that attack the photosynthesis process. New trees and other vegetation will be planted in the fall.
The work follows the Rivanna Water & Sewer Authority’s replacement of the Meadow Creek interceptor, a large pipe that carries wastewater from the city and urbanized sections of Albemarle County to the
Moores Creek Wastewater Treatment Plant
As a result of that work, the interceptor and the creek will be much further apart, reducing the chances of water infiltration of the sewer system.
“Twelve years later, it’s functioning just as it should,” Daly said.
Construction is expected to take place through the end of the year.
Daly said much of the land will be part of a future Meadow Creek stream valley park, which includes much land recently purchased by the city.
A master planning process will be held later this year to shepherd the trail development process.
“When we completed a needs assessment it showed us we had a deficiency of parkland,” Daly said. “We worked really hard to bring as much of the riparian buffers into the park system.”
As a condition of the VARTF funding, over 70 acres of land will be under permanent
. That will mean no future subdivision of land, no buildings and no impervious surfaces.
One attendee said he was concerned that the restriction on impervious surfaces could impede the ability of the city to build a network for bike commuters. However, Frisbee said trail technology is improving.
“There are options for pervious trails that can give us stability for bikes and strollers,” Frisbee said, adding that crushed stone dust could be one option.
, an elected member of the Thomas Jefferson Soil and Water Conservation District, said he was concerned that the Nature Conservancy would hold the easements.
“I have a little concern about transferring an easement to an organization I admire but don’t think should have that much control,” Collins said. He added that the community might have chosen to include gardens in the new park, but the easement eliminates that possibility.