Meteorologists downgraded Harvey to a tropical storm Saturday afternoon, and Texas Gov. Greg Abbott said the remaining torrential rain was bound to cause more flooding.
Authorities confirmed one person died in Rockport, where the storm's ferocious winds destroyed both residential and commercial property.
Abbott issued a disaster declaration for 50 counties. Rockport Mayor Charles Wax said most of the destruction happened in the coastal city. Harvey hit the area of about 10,000 residents as a Category 4 hurricane with lashing 130 mph maximum sustaining winds Friday night.
The first reports of injuries and damages were in Rockport, after a senior housing complex collapsed. Daybreak revealed debris blocking roads and damaged roofs in downtown Corpus Christi. The storm settled in over southeast Texas as a weakening Category 1 storm.
Abbott said there weren't More than 300,000 customers were without power on the Texas Gulf Coast, according to the Electric Reliability Council of Texas.
"As long as the hurricane remains over land, it is going to continuously downgrade," Meteorologist Jennifer Correa said.
After landfall 10 p.m., Friday, meteorologists reported the storm's maximum sustained winds went from 130 mph to 125 mph. Storm surge was up to 12 feet. Meteorologists determined about 5 a.m., Saturday, Harvey was a Category 2 storm and an hour later downgraded it to a Category 1 with 85 mph winds.
Harvey came ashore as the fiercest hurricane to hit the U.S. in 13 years and the strongest to strike Texas since 1961′s Hurricane Carla, the most powerful Texas hurricane on record.
The warm Gulf of Mexico waters fueled Harvey. Its transformation from an unnamed storm to a life-threatening behemoth took only 56 hours. The storm grew rapidly. Based on the atmospheric pressure, Harvey ties for the 18th strongest hurricane on landfall in the U.S. since 1851.
Scientists warned that Harvey could swamp counties more than 100 miles inland and stir up dangerous surf as far away as Alabama and the Florida Panhandle. It may also spawn tornadoes.
Rain was expected to extend into Louisiana, driven by counter-clockwise winds that could carry water from the Gulf of Mexico far inland. Forecasts called for as much as 15 inches in southwest Louisiana over the next week, and up to 6 inches in the New Orleans area.
Even after weakening, the system might spin out into the Gulf and regain strength before hitting Houston for a second time Wednesday as a tropical storm, forecasters said.