The Boulder Reservoir swim beach will be closed through at least 10 a.m. Thursday, after a routine water sampling test revealed elevated levels of bacteria.

Swimming was suspended at 3:30 p.m. today, once results of the sampling test became available. The increased bacteria levels are thought to be the result of rain runoff.

Boulder Reservoir, 5565 N. 51st St., generally closes its swim beach once, and sometimes twice, a year.

The beach will reopen once bacteria levels go down.