Dallas residents will find out next month how likely it is the Trinity River will top the levees and flood the city when the Corps of Engineers releases its “Risk Assessment”. KERA’s BJ Austin says the report uses a new method of evaluation and the Dallas levees were the test case.
Colonel RJ Muraski, with the Corps of Engineers, says it’s a new statistical method to predict the likelihood of flooding as well as strengths and weaknesses of a levee system.
Muraski: You know, how often does it rain? What are the impacts? If it does rain, how high will the water be up on there? We’ll look on the probabilities of some of those things happening, what are the physical characteristics that we know of the levee system and how can we best address some of those issues?
Colonel Muraski told the Oak Cliff Chamber of Commerce the Dallas levees were the pilot program for the Corps’ new Risk Assessment procedure that rolls out this fall. The Colonel says the report will help with long-term planning as well as the city’s urgent repairs to bring the levees up to the standard 100-Year flood protection level by the end of this year. But he’s not providing details of the report yet.
Muraski: We may find out the system’s better than we thought. We’ve done a lot of drilling. We’ve done a lot geotechnical studies and we probably know more about the Dallas levees than any other system that I’m aware of. I think that has helped us tremendously as we go through this risk assessment.
In 2009, the levees failed a critical Corps inspection with 198 violations. Later, sand was found in locations near the Margaret Hunt Hill Bridge. Sand could cause levees to fail. City officials had braced fir a 100 million dollar repair job. But they say the Corps new approach, including a focus on affordable remedies, cuts that to around 30 million.
Last month, the Corps gave the city the go-ahead to hire contractors to start the levee work. City Council members are expected to do that in a couple of weeks.