As the city conducts a feasibility study determining how to best mitigate flood risk in the Onion Creek area of South Austin, grassroots efforts continue to curb the loss of life and property.
Ken Jacob, vice president of the Onion Creek Homeowners Association and president of the South Austin Neighborhood Association, said the results of an ongoing study by the engineering firm Halff Associates may reveal solutions to reduce future floods through the use of upstream detention ponds, or low-lying land designed to temporarily hold floodwater before slowly draining once waters recede.
“This could reduce or eliminate the big surge of floodwater that comes through and wipes everything out,” Jacob said.
Because flooding is a regional issue involving multiple counties, Jacob said the solution must also be cooperative effort. A bill authored by state Rep. Paul Workman, R-Austin, aims to create a flood control district, which would allow for rules and regulations to be instituted throughout affected jurisdictions.
“The purpose is to be able to coordinate efforts and to have a way to seek and receive federal, state and private dollars,” Jacob said.
By creating an overarching entity to enact regulations on developments and construct detention ponds, Jacob is hopeful future home buyouts might be prevented—a trend he says has deteriorated communities.
“Buyouts are necessary for many of those who have already suffered catastrophic damage to their homes and for which there is no other solution, but it shouldn’t be considered a panacea for flooding if there are other alternatives,” he said.
As of March 6, the city purchased 771 properties at high risk for flooding in the lower Onion Creek neighborhood. Pam Kearfott, supervising engineer in the Watershed Engineering Division of the city’s Watershed Protection Department, said although several methods exist to mitigating flood risk, sometimes buyouts are the only sensible option.
“We don’t approach buyouts lightly,” she said. “We know they have an impact on neighborhoods, but we also know that repetitive flooding has impact on neighborhoods.”
According to Jacob, flooding in Onion Creek isn't just caused by an overflow of the creek. The city's outdated drainage system, especially in the urban core, is also to blame, he said.
"The problem is not only the creek flooding," he said. "It also entails drainage due to long neglect in maintaining the city’s sewer system due to a lack of funding and long-term planning. This will require years to correct and major funding."
On April 7, the Federal Emergency Management Agency, or FEMA, released preliminary flood insurance rate maps that govern rates for residents living within the updated floodplains. A public comment phase is now underway, and the finalized maps are expected to be released in late 2018.
Karl McArthur, supervising engineer in the Watershed Engineering Division, said FEMA instituted a new policy to help ease homeowners living within the revised floodplains into an insurance plan.
“If your home was not previously mapped in the floodplain and you are moving into it with the new map, you will start at a lower rate and gradually, over a few years, increase to the full rate,” he said.
The watershed department recently completed Phase 1 of its Onion Creek Floodplain and Flood Mitigation Study, which involved updating the floodplain maps laid out in 1980s. Phase 2 is currently underway and involves evaluating which of the various options is the most effective to mitigate flood risk in Onion Creek. The department will take results from the Halff Study into consideration when evaluating options.
“We are hoping to go back to the neighborhood in May and show them the result of the study,” Kearfott said.
Once a solution has been decided on the department will move into the engineering and design phase. Until then, Jacob and his neighbors are awaiting the results of the Halff study, slated for completion by this summer.
“We are hopeful that a solution or combination of solutions will be identified in the Halff study whereby we can greatly reduce the threat of future flooding throughout the floodplain and save our neighborhoods,” he said.