Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: FRIDAY, June 29, 1990 TAG: 9006300482
SECTION: SMITH MOUNTAIN TIMES PAGE: SMT-14 EDITION: BEDFORD
SOURCE: David M. Poole
DATELINE: LENGTH: Medium
Thom Leedom, a biologist with the U.S. Corps of Engineers, said that so much silt is pouring into some areas that dredging cannot maintain the channel.
"It's coming in there too fast," Leedom said, referring to siltation hot spots such as the upper Blackwater River.
Solutions are available, however, for property owners who live in more controlable situations, Leedom said.
Maintenance Dredging. Landowners can maintain the channel depth and width through dredging.
Leedom recommended hydrolic equipment, which acts like a giant vacuum cleaner that removes excess silt from the lake bottom. Scoop-type dredging is less effective because it leaves some material behind, he said.
Federal permits generally require dredging equipment to stay 20 feet from the shoreline and 40 feet from the back of coves. The Corps of Engineers will not allow dredging to deepen a cove, but simply maintain the depth that existed before siltation.
The cost of dredging - measured by cubic yards - is prohibitive for many landowners. The process is more affordable if several adjoining landowners pool their resources to dredge a cove or channel.
Siltation Traps. Leedom said the best way to control siltation is to trap it before it reaches the lake. But that requires the cooperation of landowners living upstream.
One way to trap siltation is to dam a creek and create a small pond in which the slow water will cause the siltation to drop out of solution before it reaches the lake. Several ponds at Stone Manor Country Club keep topsoil from washing into Smith Mountain Lake while creating a water hazard for golfers.
Cleaning siltation from a pond with a backhoe is much easier and less expensive than dredging it the lake, Leedom said.
by CNB