The Arlington County manager on July 10, 2019, declared a state of emergency after heavy rains on July 8 caused destructive flooding. (Amy Gardner/The Washington Post)

Arlington County, Va., has declared a state of emergency in response to the heavy rain and flash floods that inundated the area Monday morning and washed out streets, parks, utilities, stores and residents’ yards, leaving more than $3.5 million in damage to county-owned property alone.

The declaration, made Wednesday evening by the county manager, is a key step in requesting state and federal assistance for recovery costs. It will be formalized Saturday by the County Board.

The storm, which swept into the region between 9 and 10 a.m. Monday, dumped up to five inches of water on the suburban county, flooding shops in the Westover neighborhood. Merchants there described the deluge as “biblical.”

Blocks away, a tidal-like surge of water forced its way into yards and homes, displacing heavy yard sheds, filling basements with sludge and bursting windows from the inside. Numerous cars and trucks caught in floodwaters were totaled. County officials, stunned by the damage, appealed to residents and property owners to submit damage reports online by Friday to help the county seek federal aid. The county also is arranging debris pickups for those who are clearing out their water-saturated goods before mold sets in.

Volunteers from the Arlington Community Emergency Response Team, the Virginia Medical Reserve Corps and Team Rubicon are going door-to-door in affected areas to assist with damage assessments.