RiverSweep [1] is Ohio Canal Corridor's 18th Annual, environmental awareness and clean-up initiative developed by Ohio Canal Corridor. The event partners multiple non-profit organizations with private companies to clean areas along the Cuyahoga River Valley and its tributaries. RiverSweep is a "done in a day" event where volunteers gather at one of seven designated areas.
Links:
[1] http://www.ohiocanal.org/riversweep%202007.htm
[2] http://maps.google.com?q=%2C+Cleveland%2C+OH%2C+%2C+us