#BREAKING: Levee breach on Columbia Lake in Brazoria County.
The disaster has unfolded on a dramatic scale, with Houston - the fourth largest city in the USA - paralyzed by the storm and subsequent flooding.
The downtown areas of Brazoria, Sweeny and West Columbia were clear of major flooding Tuesday morning, Trower said.
Authorities outside Houston are urging residents of Brazoria County to evacuate immediately due to floodwaters from Harvey that breached a levee, the Reuters news agency reports.
A Houston police officer drowned in his patrol auto early Tuesday trying to get to work.
Engineers have been releasing water from the dam in order to reduce pressure on the structure, causing more flooding in the area.
The difficulty of controlling the release is "something we've never seen before", flood control official Jeff Lindner told reporters. Some levees in outlying areas are created to protect against flooding that happens every 100 or 200 years.
Two more days of heavy rain are expected over parts of Texas and Louisiana as Harvey churns offshore, preparing to make landfall again today.
According to CBS Houston, the levee in question is protecting residents from flood surge near the Brazos River near Sweeny, Texas.
As of now, fourteen people have died, and thousands have been displaced from their homes.
Calls for rescue have so overwhelmed emergency teams that they have had little time to search for bodies.
Te official death toll from the disaster stands at nine after a Houston police officer was confirmed to have drowned in the flood.
Four children and their great-grandparents were among the 14 people who have died in Texas trying to escape the floodwaters unleashed by Hurricane Harvey.