Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: THURSDAY, February 14, 1991 TAG: 9102140124
SECTION: VIRGINIA PAGE: B-1 EDITION: METRO
SOURCE: JOEL TURNER MUNICIPAL WRITER
DATELINE: LENGTH: Medium
About two-thirds of the riprap proposed for stabilizing the river banks will not be installed. It will be replaced by crown vetch, a green flowering plant often found in highway median strips and rights of way.
Riprap - stones irregularly piled together - still will be used along the river's edge and on the lower one-third of the banks.
City Manager Robert Herbert said Wednesday that a research division of the U.S. Army Corps of Engineers has recommended using crown vetch to stabilize the upper two-thirds of the river banks to prevent erosion.
The corps' research report indicates that vegetation would provide the same flood-reduction benefit as riprap, cost less and be an environmental improvement, Herbert said.
The change was welcomed by Friends of the Roanoke River, a coalition of river enthusiasts and environmentalists that had pressed the corps to study alternatives to the stones.
"This is one of the most important changes that we had sought," Bill Tanger, a spokesman for the group, said at a joint news conference with Herbert.
"The corps has a history of using riprap unnecessarily in projects all over the United States," Tanger said. "The Friends of the Roanoke River believe riprap is often environmentally harmful, and there are equally effective solutions that often cost less."
In recent years, the river group has lobbied for several changes in the flood-reduction plan, some of which were approved earlier. With the latest revision, there has been "substantial movement toward an environmentally sound" project, Tanger said. The group still hopes the corps will consider planting some trees.
This is the first time the corps has agreed to replace riprap with vegetation on a flood-reduction project, Tanger said. The crown vetch will grow to a height of 1 to 2 feet with pale pink to purple blossoms in summer, he said.
Jim Carper, the project manager, said the corps will accept the recommendation and include it in the final plan, which is to be finished this fall.
"That is our intent," Carper said, "although we will have to take it on a case-by-case basis" in some areas to be sure that the vegetation would prevent erosion.
Tanger is confident the corps will implement the recommendation. "There is no way they can back out of this," he said.
Riprap is the second-largest expense in the $34 million project, which will include widening the river channel, constructing flood walls at several locations and building a 4.6-mile bicycling and jogging trail.
Most of the estimated $1.8 million that will be saved by using crown vetch will come in federal funds. The federal government will pay 95 percent of the cost for channel improvements, including riprap. The city will pay 5 percent and save $90,000 because of the change.
Construction on the channel widening and flood walls is scheduled to begin in 1992 and take three years.
President Bush has included $470,000 for the project in the federal budget for the fiscal year that starts Oct. 1. Congress appropriated $2.3 million for the plan in the current fiscal year.
by CNB