Floodgates at two flood protection reservoirs in Houston, Texas, have been opened to allow a “controlled” release of water into the already flooded Buffalo Bayou river after a hurricane hit the city last Friday.
Flooding in the Houston area has been unprecedented as Hurricane Harvey hit Texas. Fourteen people are reported to have died in the event.
The US Army Corps of Engineers (USACE), which runs both the Addicks and Barker reservoirs in the city, said it had started releasing water from the dams because levels had increased “dramatically” at a rate of more than 150mm/h in only a few hours.
The USACE said the controlled release was necessary as an uncontrolled flooding of the reservoirs would have a greater impact on the surrounding communities.
“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 neighbourhoods and ultimately into the bayou,” said USACE Galveston district commander Lars Zetterstrom.
The release of water has swollen the already flooded river, and USACE officials expect the reservoir levels to keep rising throughout the week. It said the elevated pool levels could impact neighbouring areas behind the dams for weeks or even months.
The reservoirs were built in response to massive floods in 1929 and 1935 and were designed to detain excess water, and protect land around the Buffalo Bayou river and in Houston city centre.
Despite the high waters, the USACE said it was “confident that the structures would continue to perform as they were designed to do”.
In preparation for the storm, on Friday last week the USACE also began installing emergency power supply equipment across Texas to protect “critical” public facilities such as hospitals, water treatment plants, emergency centres, fire and police departments.