The Union Street Undercrossing in The Dalles will be closed to all traffic at times during the next few weeks due to a high Columbia River level, which is causing water at the undercrossing to be deep enough to be hazardous to vehicles.  A combination of snow melt and rain has elevated the Columbia River level and the river has overtopped the banks in some locations.  When necessary, Union Street northbound will be closed to thru traffic at the railroad tracks, and will be completely closed north of the Hattenhauer access road.  Approaching the undercrossing from the west side, West 1^st Street will be closed to thru traffic at Terminal Street and will be completely closed beyond the Oregon Cherry Growers.  Motorists are encouraged to use Webber Street as an alternate route to access West 1^st Street during times the underpass is closed.  The closure may be periodic and sometimes sustained for several days during water runoff times.