THE BURNED OVER DISTRICT

And that will send even more water flowing into Houston as the reservoirs levels rise above the flood gates. Authorities had been trying to prevent this but the rainfall has far exceeded their abilities to do so.

One of two major reservoirs in Houston began spilling over for the first time in history, despite efforts to prevent such “uncontrolled” overflow the day before, officials said.

The U.S. Army Corps of Engineers confirmed Tuesday morning that water was spilling from around the dam gates of the Addicks Reservoir, which has been overwhelmed by extreme rainfall from Hurricane Harvey. Officials said they expect the Barker Reservoir, to the south of Addicks, to begin overflowing similarly at some point Tuesday.

A Harris County Flood Control District meteorologist said the overflow from the reservoirs would eventually flow into downtown Houston.

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. Water levels in the two reservoirs had already reached record levels Monday evening, measuring 105 feet at Addicks and 99 feet at Barker.

Engineers were unable to measure water levels at the Barker Reservoir on Tuesday because its gauge was flooded overnight, said Jeff Lindner, the Harris County flood control meteorologist.

Officials had hoped to prevent just such a spillover by releasing water — slowly, at first — from both the Addicks and Barker dams, starting early Monday morning. Water levels in both reservoirs had “increased dramatically” late Sunday night, rising more than half a foot per hour, leaving engineers with two choices: to begin releasing water through the dam gates earlier than expected — or risk it spilling out suddenly around the ends of the dams.

“If we don’t begin releasing now, the volume of uncontrolled water around the dams will be higher and have a greater impact on the surrounding communities,” Col. Lars Zetterstrom, the U.S. Army Corps of Engineers Galveston District commander, said in a statement about 2:30 a.m. Monday. “ … It’s going to be better to release the water through the gates directly into Buffalo Bayou as opposed to letting it go around the end and through additional neighborhoods and ultimately into the bayou.”

The Corps planned Monday to release water at 4,000 cubic feet per second from each reservoir over a six- to 10-hour period. Officials said thousands of homes along the reservoirs could be affected, and by midmorning Monday, streets and houses in some surrounding neighborhoods had already begun flooding, ABC13 News reported.

Losing control of the water flow would magnify the disaster exponentially beyond what it is now.