WORK ON THE REPLACEMENT of the four rubber crest gates at the Coon Rapids dam in Minnesota, US, has been completed. Access to the dam area was closed in July 2001 to allow the construction work on the dam to take place.
The first phase of the gate replacement work involved gates two and three, the two shortest gates, located in the middle of the dam. Once the pool was lowered to its winter level in early September 2001, the contractor began the replacement of gates one and four, the two long gates located at the ends of the dam.
Since the reconstruction of the dam in 1997, the original rubber crest gates have failed several times. After the last round of failures in August 2000, the Japanese gate manufacturer completely replaced the four gates with new rubber crest gates of a modified design.
The new gates have been provided and installed at the manufacturer’s expense, and include a new 10-year warranty effective from the date of installation.
The Coon Rapids dam, on the Mississippi river, was built in 1913 to produce hydro power. The dam and power house were closed in 1966 and the park was opened in 1978. A new dam with inflatable rubber gates was built in 1995-7.
The dam maintains a summer pool for recreation, with no power production.