But because of the dam ’ s listing with Minnesota ’ s State Historical Preservation Office ( SHPO ), renovations could not be undertaken in any way that might adversely affect its historic properties . All renovation techniques had to be in conformance with the Secretary of Interior ’ s Standards for the Treatment of Historic Properties .
In effect , any part of the dam that was original from the 1800s was considered sacrosanct by SHPO .
“ Their approach basically was : ‘ Don ’ t touch that thing . You can work around it , but you don ’ t touch it ,’ ” Goodwin said .
Such draconian limitations seemed to present an insurmountable obstacle . How could the dam be renovated when
it was impossible to meet modern-day safety standards using antebellum construction materials and techniques ? Fortunately , Goodwin ’ s many years of experience with dam-related projects sparked an innovative idea : If we can ’ t touch the old dam , why not build a new one ?
Two Dams Are Better Than One
Goodwin has inspected hundreds of dams during his career and each year he attends several engineering conferences – so he has been exposed to a multitude of design ideas , many of which he has stored away for future use .
By blending concepts pulled from this
mental file cabinet , Goodwin derived the
idea of building a modern dam directly behind the historic stone arch dam . The beauty of Goodwin ’ s idea is that it met the seemingly irreconcilable goals of enhancing the Lanesboro Dam ’ s stability without detracting from what makes it a national historic treasure .
So in the summer of 2020 a modern cellular dam was constructed directly behind the historic limestone dam . This second dam consists of six interlocking circular steel cells . Each cell with a concrete base and cap , filled with rock and stone .
Throughout the process of constructing the cellular dam , vibration sensors carefully monitored the work to ensure no harm was done to the historic dam it was designed to protect .
Funding Shortage Killed Initial Restoration Effort
An initial attempt at restoring the
Lanesboro Dam was undertaken beginning in 2011 but eventually shelved in 2012 .
During that time , Pete Haug , an Ayres water resources engineer , directed a 65 % project design for the dam ’ s restoration . But negotiations with Minnesota ’ s State Historical Preservation Office ( SHPO ) and other state agencies resulted in the finding that the only way to meet SHPO standards for work involving historic structures would be to rebuild the dam out of limestone blocks .
That requirement was simply too expensive , so the project was shelved until 2017 , when Minnesota state Legislature appropriated the funds needed to resume the project .
At that point Chris Goodwin of Ayres took over as project manager . The project was completed in the fall of 2020 at a cost of just over $ 4 million .
“ This project had tremendous support , not only from the Lanesboro community but from surrounding communities as well . And , most importantly , our state Legislature was very supportive ,” said Michele Peterson , Lanesboro ’ s city administrator / clerk . “ With our small tax base we could not have done this alone .”
The project also was funded through a U . S . Department of Agriculture Rural Development Loan and it was permitted through the SHPO , the U . S . Army Corps of Engineers , the Minnesota Department of Natural Resources , and the Minnesota Pollution Control Agency .
– Bob Brown
18 | TRENDS Ingenuity , Integrity , and Intelligence .