Hyde Park area residents point to flooding causes

Flood maps in hand, several Hyde Park area residents pointed to poorly designed sewer drains and a blocked retention pond pipe as major contributing factors to the area’s Memorial Day flooding.

Tanya Quinn and Mary Ingle, who live near the intersection of East 33rd and Grooms streets, asked Austin’s Environmental Board for an updated flood study on the Hemphill Branch of Waller Creek, which flows near their properties. The intersection has flooded twice since July 2014 and increased construction in the area has made it more vulnerable, Quinn and Ingle said.

“I have photographs to just show you my story,” Quinn told the board on Wednesday. “I think in July (2014), we had that major rainstorm, and I live at the bottom of the hill … I (had) purchased a brand new car, and it was totally flooded.”

To help address the localized flooding, the city put in an additional drainage sewer at the intersection in January, Quinn said.

After more than 8 inches of rainfall this Memorial Day, however, the newly installed drainage sewer backed up so severely that manhole covers blew off, Ingle said.

Quinn said she thinks that the improved stormwater drain still inadequately addresses flooding issues even during normal rains because of its limited pipe size and varying curb heights, which cause water to overflow into yards.

Scott Prinsen, who works in the city’s Public Information Office, told the Austin Monitor that the city of Austin’s most recent floodplain study involving the Waller Creek watershed was completed in 2008. The study was approved and incorporated into the FEMA floodplain maps in 2010, Prinsen said. But, he added, the FEMA floodplain maps don’t show the East 33rd Street and Grooms Street intersection in a designated floodplain.

Two other residents at the meeting, however, pointed to a blocked drainage retention pond in the Triangle Apartments complex as the possible cause of flooding near East 33rd and Grooms, as well as areas along Guadalupe Street.

Residing on the western side of 33rd Street, Rick Iverson and Mark Feist said construction debris consistently blocks a 46-inch drainage pipe that allows overflow into and out of the retention pond near the intersection of Guadalupe and West 45th streets.

“This flood, and I know this was a historic flood on Memorial Day, but Rick and I don’t think our neighborhood would have been flooded had the retention pond worked, and it got blocked once again,” Feist said.

Feist said the pipe was blocked during the July 2014 floods as well.

Iverson, who has worked with the city for decades on drainage issues in the area, said he believes the retention ponds around the Hemphill Branch of Waller Creek are sufficient to handle severe flooding, but that the blockage makes them ineffective.

The two pointed out to board members that the pipe in the Triangle’s retention pond has no filter or guard on it, which might prevent future clogs. Feist suggested “some sort of engineering effort” could prevent downstream flooding in the future.

Environmental Board Chair Mary Gay Maxwell, who also acknowledged the public speakers as her neighbors, directed city staff to look into the problems.

This story has been corrected.