Engineering the Falls The pace of the erosion of St. Anthony
Falls increased after lumbering and milling began. Logs floating
downriver crashed against the limestone and broke it off in
great chunks. To prevent further damage, the U.S. Army Corps of
Engineers built a concrete dike under the river and placed a
wooden apron over the ledge. The Corps later replaced that apron
with the current concrete spillway. It protected the falls, but
their natural beauty was forever transformed. In 1878, William
de la Barre, a young Vienna-born engineer, called on owner
Cadwallader C. Washburn after the Washburn A Mill explosion with
a flour dust collecting device that he said would prevent such
accidents. Washburn hired him to oversee the rebuilding of the A
Mill. He stayed on as engineer for the milling companies that
controlled the use of the falls. By studying seasonal effects on
the river and falls, he improved the water distribution system
and increased the over-all output of waterpower nearly six
times. To maintain a