Written by Rod Scott
When 85 of Iowa’s 99 counties were declared disaster areas after last June’s devastating floods, preservationists jumped into action. As President of the Iowa Historic Preservation Alliance (IHPA), a statewide volunteer membership organization, I traveled throughout the flood zone providing expertise, assistance, and moral support to owners of historic properties damaged in the disaster.
Iowa’s historic mills, located by necessity along the riverbanks, were hit with the full force of the floodwaters. The IHPA partnered with the Silos and Smokestacks National Heritage Area and the Buchanan County Historical Society to bring experts from Trillium Dell Timberworks, a Knoxville, Illinois company specializing in heavy timber restoration of historic structures, to assess flood damage at three of Iowa’s historic mills.
The 1875 Wapsipinicon Mill in Independence, Iowa’s biggest and one of the largest historic mills in the Midwest, had been seriously damaged in the flood. The ground floor or meal floor, where goods were originally sacked, had uplifted and collapsed, and several of the original floor girts had washed downriver. Trillium Dell Timberworks determined that the severity of damage was significantly exaggerated by the loss of the original structural integrity of the floor system.
Perhaps because our ancestors better understood the inevitability of flooding when they built alongside the rivers, historic mills were specifically designed to withstand floodwaters. Motor Mill and Potter’s Mill, the two other historic mills assessed by Trillium Dell Timberworks, were relatively unscathed by the 2008 floods. In contrast, the meal floor of the Wapsipinicon Mill had been radically altered in 1906 when the original floor girts and posts were cut short and left unanchored to accommodate new concrete columns carrying building and machinery loads. This configuration effectively interrupted the originally well-engineered floor system, allowing the floodwaters to cause serious damage to the historic building.
The good news is that FEMA has now agreed to fund both remediation and mitigation at the Wapsipinicon Mill, and Trillium Dell Timberworks will oversee the work. Because the 1906 piers are now a part of the history of the mill, Trillium Dell Timberworks designed a mitigation plan that retains those piers while effectively restoring the structural matrix and flood-resistant design of the original meal floor. The plan also calls for all timbers and flooring to be rot-resistant white oak, as originally used in the meal floor, and to exhibit matching milling characteristics.
The partnership between IHPA, Silos and Smokestacks, the Buchanan County Historical Society, Trillium Dell Timberworks, and FEMA demonstrates that honoring historic means and methods not only preserves our cultural heritage, but is also cost effective: with the structural integrity of the floor system restored, future floodwaters are unlikely to do more than cosmetic damage to the historic Wapsipinicon Mill, allowing it to grace the riverbank for another 130 years- literally, come hell or high water!
Rod Scott is the President of the Iowa Historic Preservation Alliance.
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