PORTLAND, Ore. (AP) -- Two people caught skinny dipping in a Portland reservoir that is a main source of water for the city nearly caused officials to dump millions of gallons of water and close the facility.

Ryan Langsdorf, 28, and Ashley Moyer, 23, were found in one of two sections of the Mount Tabor Reservoir at about 3 a.m. Saturday during a spell of unusually hot weather. They were cited for trespassing.

But the two were swimming in a section of the reservoir that was not being used. Had that section been in use, water bureau officials say they would have had to dump millions of gallons of water from that pool and possibly shut off the reservoir.

Earlier this year, millions of gallons of water were dumped when someone put latex paint, a construction cone and hundreds of flyers into the water.