PORTLAND, Ore. -- Portland Water Bureau officials are reviewing security cameras to help catch whoever dumped tennis balls, informational fliers, a construction barricade and a two-gallon jug of latex paint into the Mount Tabor Reservoir water supply system.

The objects were removed Tuesday and the entire reservoir, one of three on Mount Tabor, will be drained and cleaned.

The bureau says it will prosecute the culprit and charge for the 30 million gallons of water that must be prematurely drained from the reservoir.

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Water Bureau Administrator David Shaff called the incident a "disgusting act of vandalism and assault on this community."