PORTLAND, Ore. –- Reservoir security at Mt. Tabor was put in the spotlight after a pair of people were discovered skinny dipping there over the weekend.

Portland Water Bureau security personnel discovered the pair in Mt. Tabor Reservoir 6 early Saturday morning.

They notified police, who ordered Ryan Langsdorf, 28, and 23-year-old Ashley Moyer out. Officers cited Langsdorf and Moyer for trespassing.

Incident report: Suspects were afraid they'd go to jail

The reservoir is divided into two sections. The section in which the swimmers were caught was currently off-line. Had it been in use at the time, the Water Bureau would have been forced to shut off the reservoir and consider dumping millions of gallons of water, said bureau spokeswoman Sarah Bott.

The water from the reservoir goes into the tap water supply without being filtered.

Photos courtesy Portland Water Bureau

Ryan Langsdorf, left, and Ashley Moyer were cited for trespassing.

"Not only did this foolish act threaten the cleanliness of Portland's drinking water, it was just plain dangerous," said Water Bureau Administrator David Shaff. "These two individuals could have easily found themselves in a precarious situation where extremely cold water temperatures and a difficult rescue situation could have made drowning a real possibility."

The Water Bureau will work with authorities to pursue this case to the fullest extent of the law, according to Bott.

The incident highlights an ongoing debate about whether to cap the reservoirs. The Federal government has been pushing cities to cover their drinking water reservoirs. The projected cost in Portland would be $500 million.

Also: Reservoir ruling would cost Portland $500 million

It was the sixth skinny-dipping incident at the reservoir in the last 25 years, officials said.