SAN FRANCISCO » A water manager is facing discipline after he was caught urinating in an empty reservoir that supplies drinking water for the San Francisco Bay Area.

San Francisco Public Utilities Commission spokesman Tyrone Jue said Monday that the agency confirmed anonymous complaints that maintenance planner Martin Sanchez had urinated in the 674-million-gallon reservoir in the Sierra Nevada foothills early last month.

The reservoir had been drained for maintenance, and officials say public health wasn’t in danger.

Sanchez, who earns $111,000 annually, was in line for a promotion before the incident. He now faces a maximum penalty of a weeklong suspension without pay.

A message left with Jue seeking comment from Sanchez wasn’t immediately returned.

San Francisco’s water comes mostly from Sierra Nevada runoff.

Last year, a 19-year-old Portland, Oregon, boy was cited for public urination and trespassing after he was accused of urinating in a 35-million-gallon city reservoir.

After learning of the incident, Portland officials began dumping water into the sewer system, but the process was slowed by heavy rains. As a result, they diverted the water to an empty reservoir and used the supply for nondrinking purposes.

It was the second time in less than three years Portland has emptied a reservoir due to concerns that someone had urinated in the water.