[audio:http://www.wdde.org/wp-content/uploads/2014/12/TheGreen_12192014_WhiteClayDam.mp3|titles= Delaware Public Media's Tom Byrne and contributor Jon Hurdle discuss the removal of a Colonial era dam on the White Clay Creek.]
A few yards from the winding trail that takes golfers around the White Clay Creek Country Club next to Delaware Park Racetrack, two mounds of rough timber and stone mark the site of the state’s first removal of a historic dam in an attempt to restore a valued natural asset.
The stone and timber are all that remains of a Colonial-era dam that was partially demolished in early December in an effort to entice fish, especially shad, to return to their upstream spawning grounds for the first time since the dam was built in 1777.
After more than three years of planning, a three-day operation removed the middle 40 feet of the dam but left 30 feet untouched on each side of White Clay Creek in a compromise between the historians who wished to preserve the structure, and naturalists who want to return the creek to its natural state.
“The original plan was to remove the whole dam but we came up with a plan to balance the need for fish passage and preserve the remnants,” said Jerry Kauffman, Director of the University of Delaware’s Water Resources Agency, who leads the project.
Recognition of the dam’s historic value, and the environmental potential of its removal resulted in a long process of planning that preceded its removal, he said.
“It took about three days to deconstruct the dam; it took three a half years to obtain the approvals; so we very carefully went through a historic discovery and documentation process,” Kauffman said.
The operation was the first stage in a plan to meet the requirements of the federal government’s designation of White Clay Creek as a Wild and Scenic River – which must be free-flowing.
The status of “Wild and Scenic” – conferred on the creek during the Clinton Administration -- gives the creek the highest level of federal protection, and puts it on a level with iconic American rivers such as the Colorado and the Columbia, Kauffman said.
Officials will over the next five years remove six more dams – some of them historic – on the 35-mile creek that has its headwaters in Chester County, Pennsylvania, and flows eventually into the Christina River.
The overall project is costing around $200,000, funded by grants from the National Fish & Wildlife Foundation; the Fish America Foundation, and American Rivers.
Some of the demolition work had already been done by storms and floods, most recently by Superstorm Sandy, over the previous 237 years, partly removing the central section of the dam, officials said.
Kauffman has high hopes that shad will return to spawning grounds upstream of the dam starting in next year’s shad season from March 15 to June 15. Even before the central section of the dam was removed, the fish could be seen in their thousands, gathering at the foot of the old structure.
“We know they are here,” he said. “We’ve done fish abundance surveys with the Delaware Division of Fish & Wildlife. Thousands are schooling at the foot of the dam.”
“Everybody is looking forward to spring 2015 to determine how far they will swim,” he said.
He’s hoping the fish will be able to swim 3.6 miles upstream to the next dam which is already breached and may allow the “most hardy” of the shad to reach a third dam in the City of Newark.
Some of the fish will be tagged with GPS receivers that will allow biologists to monitor where they swim, when they spawn, and how long they stay in their new spawning grounds.
The return of the shad would help revive a sport fishery that was an important part of local culture in the 19th century when the fish were abundant, Kauffman said.
It would also have wider ecological benefits such as providing more food for bald eagles, some of whom already nest along the creek, and increasing the population of freshwater mussels, which are an important water-filtration system, and would spread upstream by attaching themselves to the migrating fish, he said.
Water quality has improved to the point where there is a good level of oxygen for the fish to live, Kauffman said. The control of industrial and agricultural outflows into the creek, thanks to the federal Clean Water Act of 1972 has raised oxygen levels from a negligible level to around 10 parts per million, well above the level at which water is officially “fishable,” he said.
Better water quality in the creek also has wider benefits for Delaware, which gets 20 percent of its drinking water from its 100-square-mile watershed, Kauffman said.
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For historians, the dam removal provides a rare glimpse into the economic history of the Revolutionary War period when George Washington was planning to defend Wilmington from attacking British forces, said Craig Lukezic, an archaeologist with Delaware’s Historic Preservation Office.
“It gives a really good look at the construction techniques from this period that we don’t usually see,” Lukezic said.
Materials recovered from the dam include about two dozen logs up to 32 feet long and two feet in diameter, and a number of cross members about 18 feet long and 6 - 12 inches in diameter.
The artifacts also include iron spikes, measuring between one and four feet long, that were used to hold the dam together. Some of the spikes and timbers are still visible in the structures that remain on each side of the creek.
All of the recovered materials were taken to a laboratory at the University of Delaware where the logs will soon be covered in water to prevent the deterioration that would occur if they were exposed to the air for too long after such a long period immersed in water.
Researchers discovered deeds in Pennsylvania’s Chester County courthouse showing that the dam was built by Daniel Byrnes, a local miller, to provide the water power for his mill, built between 1775 and 1777.
“Delaware has an incredible history of industrial development, and the power of the development was dams and mills,” Lukezic said.
But by the 19th century, such mills started to fall victim to competition from cheap flour shipped by rail from the Midwest, and from turbines, which represented improved technology, Lukezic said.
More than 100 years after its demise as a working dam, its materials offer a rare look at construction techniques of early America, he said.
“You see the cribbing and the stone as they would have built it, and the slabs of wood,” he said. “It’s a really good example of what we have in this area.”