Thousands of residents north of Tampa are being urged to evacuate a week after Hurricane Irma’s rains are overflowing the Withlacoochee River. Hernando County Sheriff’s officials said Sunday the river has reached major flood stage at the Trilby gauge. The river is currently at 16.79 feet and is expected to crest at 17.5 feet Wednesday. The crest is expected to last two days before receding. Water is already covering the streets and as high as mailboxes in some places. Deputies have gone door to door encouraging residents to leave, warning they may not be able to rescue them once the waters reach a certain level. Four thousand residents in the Brooksville area are under a voluntary evacuation. Authorities said more than 1,900 properties could flood.The Withlacoochee River hasn’t seen this level of flooding since the 2004 hurricane season.