Pierce County online flood map January 7, 2009 12:00 am Tags: location, online flood map, Pierce County (IMAGE COURTESY PIERCE COUNTY) Pierce County has established a map online to keep residents apprised of current river flooding conditions. Click here to view the map: http://matterhorn9.co.pierce.wa.us/floodMonitor/floodforecast.jsp Tags: location, online flood map, Pierce County