The Twin Cities River Rats Water Ski Show Team perform four free, hour-long water ski shows on the Mississippi River on July 18-19, As a part of the 2009 Minneapolis Aquatennial. The Aquatennial is the official civic celebration of the City of Minneapolis. Entering its 70th year, Minneapolis residents, workers, and tourists have come to love and appreciate all that the City of Minneapolis has to offer during the Aquatennial Festival.