By the time they’d heard about it late Sunday, it was already dark and too late to get out. The U.S. Army Corps of Engineers owns and operates the reservoirs.

“If water is not in your house in these areas behind us, it will probably not be in your house”, Flood Control District meteorologist Jeff Lindner said during a press conference Wednesday outside of Addicks (next to the section where the uncontrolled release of water is spilling over the dam).

This week, for the second time in as many years, a storm has pushed the Addicks and Barker dams to their limit. Dr. Edmund Russo, with the Corps of Engineers, said 25 inches of rain had already been added to the reservoir.

Near the Addicks Reservoir, officials expect some of its water to make its way to Rummel Creek and down to Buffalo Bayou at some point during the next 24 hours. Some homes could be inundated for a month.

“I’m kind of in shock about all this going on”, said David Clemensen, 53, as he watched the water rise on his front lawn, wondering if he should flee with his sister and five children.

The storm could be one of the costliest natural disasters in the nation’s history.

The forecast calls for more rain through the week, exacerbating the situation.

The reservoirs, which flank Interstate 10 on the west side of Houston, flow into the Buffalo Bayou and are surrounded by parks and residential areas. Officials say they have dam safety experts monitoring the releases around the clock.

“This flood event will exceed the 2016 tax day flood elevations”, Zetterstrom said.

Texas Governor Greg Abbott said yesterday 54 counties had been declared state disaster areas and he plans to add 1,000 more National Guard personnel to the flood battle.

Schools, airports and office buildings in Houston were ordered shut as scores of roads were turned into rivers by floods and chest-high water filled numerous neighbourhoods in the low-lying city.

Rapid development of Houston is expanding the city’s flood plain, intensifying the impact of hurricanes, she said. On Monday, the Army Corps began controlled releases for both reservoirs that have taken on record rainfall.

Of course, that all depends on what happens in the coming days.

Both reservoirs are rising more than half a foot per hour“, Zetterstrom said, as quoted by ABC News.

“Our infrastructure is certainly being tested to its limits”, Linder said.