Building a bridge to the future with an historic dam
Under a sparkling blue sky, the waterfall is busily at work at Pawtucket’s Slater Mill Dam.
The only problem with this iconic 171-foot stretch of dam is that the water is going the wrong way.
“The water is going under the dam, instead of over it, and that endangers the dam,” said National Grid’s Bill Howard. He’s the environmental manager taking charge of this historic project.
But now, National Grid, which owns roughly three quarters of the dam in partnership with Old Slater Mill Association, which owns the remaining quarter, is in the process of making repairs.
The issue is a void that developed under the dam, forcing the water to flow underneath, said Howard. That hole was caused by natural wear and tear.
In 1944 the original wooden cribbing that had been put in place in 1792 was reinforced with concrete. For decades the six-foot high dam funneled the water down to the neighboring Main Street Dam, just a stone’s throw away on the river.
“There’s a historic reason for this dam to be repaired,” Howard said. “The Slater Mill started the Industrial Revolution in America.”
Fixing the void under the dam first requires a dry space for workers to tackle the repairs.
In September, a barge was installed above the mouth of the waterfall. This platform allowed workers to place bags filled with 1.5 tons of sand into the hole.
That made it safe for workers to begin installing a cofferdam, which will create a watertight enclosure above the hole in the dam, so that workers can plug the hole with concrete.
National Grid acquired majority rights to the dam and water after the Blackstone Valley Electric Company merged with Narragansett Electric Company, which in turn was acquired by National Grid. The remaining portion of the dam remained with the Slater Company and its successors until the dam and the mill buildings were transferred to the Old Slater Mill Association (OSMA) in 1921.
“Since its founding in 1921, the Old Slater Mill Association (OSMA) has remained dedicated to the preservation of the Old Slater Mill National Historic Landmark District, not only for its cultural significance but also for its graceful presence on the landscape of historic downtown Pawtucket, Rhode Island and the lower Blackstone River Valley,” said Lori Urso, Executive Director for OSMA.
Upon completion of the repairs to the dam, National Grid will transfer ownership and water rights to the OSMA.
“National Grid felt that the investment in the dam repair and the preservation of this iconic waterfall in exchange for relieving our customers of any future costs associated with owning a dam was the right thing to do,” said National Grid’s Lori Spangler, a manager in the Customer and Community Management Team.