Water Wheel Axle Cracks at Colvin Run Mill in Great Falls

Grinding with the main stones at Colvin Run Mill Historic Site has come to a stop for at least the next few months. Miller Mason Maddox earlier this month found a crack in the main axle of the site’s water wheel, which catches the water flowing through the millrace and powers the mill, according to a news release from the county. Colvin Run Mill, located at 10017 Colvin Run Road in Great Falls, is a popular year-round destination owned and operated by the Fairfax County Park Authority.

The mill’s general store usually sells grits, cornmeal and flour ground at the mill.

Although the mill’s main stones cannot grind grain until the shaft is replaced, tours and interpretation of the historic site will continue. The park is hosting Friends of Colvin Run Mill Day on Oct. 19, and any visitors who sign up to join the supporting Friends group on that day will receive a free and rare Four Floor Tour of the mill. That’s an extended tour of the site that includes access to areas usually not open to the public.

The 6,000 pound axle that cracked was made from the trunk of a single white oak tree and was installed as part of an update to the mill in 2001 when the existing water wheel was built. The lifespan of such woodworks is typically 10 to 15 years, and park staff knew that it had begun showing its years. Replacement of the shaft will take at least several months, and staff is not yet certain when the entire mill will be running again. The current water wheel will be disengaged, and the wheel and its spokes will be inspected for wear and damage that will determine how much of the structure requires replacement and how long that replacement will take.

The current restoration that is already under way inside the mill will continue. The installation of a shaft that will allow the mill to run at full capacity for the first time in decades is not affected by the crack in the water wheel axle, although it does mean the new installation cannot be tested until the water wheel repairs are completed.

For more, visit Colvin Run Mill Historic Site online or call 703-759-2771.

PHOTO courtesy of Fairfax County