Pace of dam removals accelerating across region

By Karl Blankenship

In mid-August, when river advocates gathered on the banks of Virginia's Rivanna River to announce the breaching of the Woolen Mills dam, they heard something unknown for nearly two centuries.

The summer drought had been broken by rain the previous night, raising the level of the river through Charlottesville; the Rivanna was flowing freely through a portion of the breach.

"That was probably the first time in 177 years that you could hear the river there," said Jason Halbert, a volunteer with the Rivanna Conservation Society who had been working to remove the dam for six years.

A rarity until a few years ago, dam removals are becoming commonplace around the region as biologists seek to open historic spawning areas for migratory fish and help return streams to a more natural condition.

They have a daunting task: In past centuries, dams were built by the thousands. First, they provided power for the Industrial Revolution, running mills and providing water to a vast network of canals. Later, they provided electricity, city water supplies, flood prevention, recreation and a host of other services.

The Chesapeake Bay watershed alone has more than 2,500 dams, shutting most of the rivers to spawning runs of shad, herring and other species that once numbered in the millions.

Nonetheless, the pace of removals is quickening. This was the first year in which Pennsylvania, Maryland and Virginia each removed multiple dams within the Chesapeake watershed.

Some of this year's highlights include:

• In Pennsylvania, the McCoy-Linn Dam, an aging 14-foot-high, 150-foot-long structure in Centre County was removed in August. "It is on, arguably, the best wild trout stream in the commonwealth, and there is a significant amount of habitat that is going to be opened up and created for the trout population there," said Dave Kristine, of the Pennsylvania Fish and Boat Commission. Also, the Wittlinger Dam on the Yellow Breeches Creek near Boiling Springs was removed. The dam, about 4 feet high and 90 feet long, was storm damaged and became a hazard.

• In Maryland, a 4-foot-high earthen dam was removed on the Puckum Branch of the Nanticoke River in January, opening 4.5 miles to alewife, blueback herring and perch.

  This fall, the Pittsburgh Plate & Glass Dam, an old pile of rubble across the Potomac River near Cumberland, was removed. Also slated for demolition is the Raven Rock dam, a concrete and mortar barrier to brook trout movement on Raven Rock Creek near Hagerstown.

  "We're definitely looking for removals rather than ladders," added Jim Thompson, fish passage coordinator with the Maryland Department of Natural Resources. "We have a bunch queued up for next year."

• In Virginia, the Quinn Dam on the Tye River, a 6-foot-high blockage on the James tributary near Lynchburg, was also removed, opening 20 miles of habitat to migratory fish. "Local canoeists and people around the state are also pretty excited because it's a popular river to canoe, and the dam has always been a problem," said Alan Weaver, fish passage coordinator with the Virginia Department of Game and Inland Fisheries.

For years, most efforts to clear the way for fish focused on building fish ladders or other passages. Giant elevators were even built at some dams on the Susquehanna River to hoist shad and other species over the obstructions.

Yet even the best designed passages can still pose significant hurdles for fish. On the Susquehanna this year, 25,464 American shad were lifted over the Conowingo Dam -- the first obstruction on the river. Only 192 made it past all four dams that close most of the river.

In contrast, Weaver said, dam removal is "basically 100 percent effective at fish passage."

More than migratory fish benefit. Dams fragment, and degrade, habitat needed for local fish, such as brook trout. When the Reedsville Dam was removed on Tea Creek in Pennsylvania's Mifflin County in 2004, the biomass of brook trout doubled within a year, Kristine said.

Pennsylvania leads the nation in dam removal -- it has eliminated more than 70 in recent years.

Others states in the region are joining the effort. The trend was punctuated in February 2004 when 650 pounds of explosives breached the 770-foot-long Embrey Dam on the Rappahannock River outside Fredericksburg, VA. Until then, there were no free-flowing rivers that linked the Chesapeake Bay with its mountain headwaters.

None of this year's projects were as big or dramatic as Embrey. Woolen Mills, the largest dam removed, opened 16 miles. But biologists say the bits and pieces add up. "More habitat, more fish is our philosophy and seems to be a good way to look at it," Weaver said.