Traffic is flowing again on Allen Parkway after high water in the Montrose Boulevard underpass created a detour for drivers.

The high water stranded two cars Saturday night as drivers tried to plow through the high water.

The water was still there Monday morning, catching many rush hour drivers off guard.

“Our field investigators have determined that a power outage from the storm caused the pumps to lose service,” said City of Houston Public Works spokeswoman Alanna Reed.

When KHOU 11 asked why it took from Saturday evening until Monday morning to clear the underpass, Reed said she wondered the same thing and was looking for someone to provide an answer. We have not yet heard back.

If a pump is knocked offline, it doesn’t automatically restart itself; someone must manually reset it, which is exactly what a crew did in just more than an hour. With the pump working, the drains did their job and the water disappeared within minutes.

Another issue on Saturday evening was that the solar-powered warning lights that are supposed to alert drivers about high water didn’t turn on.

“We’re trying to determine why those didn’t get activated,” Reed said. “There is a threshold as to when those lights get activated, so if it wasn’t deep enough, they might not have gone on.”

Once the underpass was safe for drivers Monday, crews loaded up the barricades and opened it back up to traffic.

Reed stressed calling 311 if you see standing water in underpasses, so crews can try to solve the problem as quickly as possible.