The Water System
The restoration of the tailrace was completed first, and then work began on the headrace. Every part of the headrace project led to a surprise. When the first part of the parking lot was excavated, the original race walls were discovered only two feet below the surface. These walls were carefully exposed, cleaned, and repointed so that concrete could be poured behind them. A new bridge was constructed over the original abutments. Then, when the second half of the parking lot was excavated, instead of finding stone walls, beams for a planked flume were discovered beneath the iron flume. Since evidence in both the gristmill and the Madison Factory pointed to previous hydraulic damage, most likely from the leaking wooden flume, we decided to continue with the stone walls to protect the mill. As tons of silt were removed from the head race, a puzzling feature appeared: the foundation of a stone wall perpendicular to the flow of water. Why build a wall across the canal? The answer became clear when a planked race mirroring the stone wall downstream near the control gate was uncovered. These two features together would make a short race, possibly from the earlier Swedes Mill. Sometime in the 18th or 19th century, Red Clay Creek cut a course around the original 17th century dam site. This required construction of a diversion channel and main dam to recapture the water and supply power to the three water wheels (gristmill, Madison Factory, and sawmill). In the final phase of the water system rehabilitation, a sandbag dam was placed across the mouth of the race. While the water flow was stopped, stones were repositioned and the dam structure was encapsulated in concrete, stabilizing it and protecting it against continued decay. The main channel was left open where the dam had washed out years ago. The current water system contains elements from the 17th, 18th, 19th, and 20th centuries. On October 7, 2001, State Senator Patricia Blevins and New Castle County Executive Tom Gordon installed the ceremonial Golden Bolt in the rebuilt water wheel. Then Tony Shahan, Executive Director, waded into the water and removed the sandbags preventing Red Clay Creek from flowing into the millrace. Those in attendance walked along the millrace, following the water as it made its way from the creek to the mill. Once again, the water was available to provide power to the mighty 18-foot water wheel, bringing the life force back to the mill. The Water Wheel Turns Again After the formal ceremony, Congressman Castle and Jack Williams, winner of the “Turn-on-the-wheel” raffle, turned the crank that controls water flow to the wheel. The giant wooden wheel began to revolve, a thrilling moment for the spectators, especially all of those who worked so hard to see it happen. This was the first time a water wheel has supplied power to the mill since 1870, when the wheel was replaced with turbines. |
The
study of Greenbank Mill's water system uncovered the three
hundred year story of man's struggle to harness nature. As
volunteers started clearing the race canals of brush and overgrowth,
mill features again became visible: dams, the control gate,
and the bulkhead. Archaeological and documentary research led
to a greater understanding of how the water systems worked.
Evidence suggests that three different races may have existed:
a short race half the length of the current water system, a
stone-lined race from the bridge at the parking lot to the
railroad trestle (with a wooden flume that carried the water
from the bridge to the wheel), and the current race with a
diversion channel and an iron flume to feed water to the turbine. 
After adjustments to the millrace gates and final connections
between the water wheel and the mill machinery were completed,
Greenbank Mill dedicated the reconstructed 18-foot diameter
water wheel on April 27, 2002. The dedication ceremony featured
Frank McKelvey, who spoke on “Remove Not the Ancient
Landmarks.” Other speakers included Congressman Mike
Castle, State Representative Deborah Hudson, State Senator
Patty Blevins, and Brian McGlinchy, representing U.S. Senator
Joe Biden. Greenbank received accolades from the U.S. Congress,
the Delaware Legislature, and Governor Ruth Ann Minner. Special
thanks were expressed to Mike Ciosek and Al Grunfeld for helping
to repair the wheel.