January Update on Lake Houston Area Flood Mitigation Projects

High-rise development in the floodplain has pushed Lake Houston Area flood mitigation projects out of the headlines lately. So here’s an update on where things stand from Stephen Costello, the City of Houston’s chief resiliency officer and Mayor Turner’s flood czar.

Extending Dredging to Include Mouth Bar

It’s becoming increasing unlikely that we’ll be able to piggyback on the current dredging project. The City and Federal Government are still arguing about how much of the mouth bar existed before Harvey.

The mouth bar almost totally blocks the West Fork where it meets Lake Houston. FEMA and the City of Houston have argued for almost a year over how much existed before Harvey.

Regular readers may remember that FEMA and the Corps stonewalled action on the mouth bar because of the Stafford Act. The Stafford act is the enabling legislation for FEMA. It bars using disaster relief funds to address pre-disaster issues such as deferred maintenance.

The two sides argued for almost a year about how much of the bar existed before Harvey and how much resulted from Harvey. They have finally agreed on a procedure to answer that question. It’s called the Stockton Protocol and was developed at Stockton University in New Jersey to answer similar questions after Superstorm Sandy.

The protocol involves analysis of core samples from the mouth bar. According to Costello, the City hired a geomorphologist to harvest the core samples last week. It should take two to three weeks to analyze the layers in them.

Mouth Bar Disposal Issues Drag Out, Too

Another issue regarding the mouth bar has to do with disposal of the dredged materials. The City and the Corps have tried to agree on and permit a site since October 11 of last year. Three issues come into play when evaluating such sites: volume, cost and environmental considerations.

Next phases of dredging (proposed)

The site must be large enough to accommodate the volume of dredged materials.

The site must also be close to help hold down costs. The farther the site, the higher the costs. The amount of booster pumps, diesel fuel, pipeline, and manpower needed all increase with distance.

Re: environmental considerations, the Corps would prefer a below-ground site such as an old sand pit. That reduces the chance that sand and silt will end up back in the river during the next flood. It also eliminates the issue of possibly reducing the volume of the floodplain. On the other hand, above ground sites are easier to find and one exists that is much closer than any abandoned mine.

At the moment, managers are trying to find the optimal solution given all three variables.

Of course, the volume issue will depend on how much FEMA agrees to remove – after analysis of core samples and after the federal government resumes business.

Rapidly Shrinking Window to Save $18 Million

Before this process started dragging out, taxpayers had a chance to save $18 million. That represents the cost of mobilization and demobilization of the current dredging program on the West Fork. Piggybacking the mouth bar project on top of the current project would eliminate that cost for Phase II because the people and equipment would already be on site and could just continue working.

The current project should end in late April or early May. Costello says the City is already starting to look at contingency plans in case the shutdown drags on or permitting the disposal site becomes problematic.

Contingency Plans Considered

DRC, the company engaged to clean up debris in the lake, also does dredging. DRC has already bid the job and agreed to work for the same price as the current dredgers.

The leading permittee for the disposal site has agreed to store the dredges on his property if necessary until Phase II kicks off.

Current Barriers to Reaching An Agreement

But in the meantime, huge questions remain about volume and cost. With core samplings not yet analyzed, it’s hard to determine how much material will have to be removed from the river. So it’s also hard to determine whether the available money will stretch far enough to remove everything FEMA approves. At this point, the City has committed $15 million and the State $50 million. FEMA remains the big question mark.

Next steps:

  • Analyze core samples and agree on volume to be removed
  • Agree on disposal site and permit it
  • Determine available funds
  • Develop a dredging plan optimized for all variables above
  • Execute the plan

Status of New Gates for Lake Houston Dam

New gates for the Lake Houston dam also remain in limbo. Costello met with FEMA in December and again in early January. FEMA questions the benefit/cost analysis presented by the City. The City originally estimated a 2.8 b/c ratio for the project. That put it high on everyone’s priority lists. However, that may come down. Costello still believes the ratio will come in above 1.0, the cutoff (because benefits still exceed costs). A consultant is currently reconfiguring the estimate.

Lake Houston Dam is primarily a spillway. Small floodgates can lower lake if given enough time. But that requires starting before weather predictions acquire a high degree of certainty, thus raising the risk of wasting water if the forecast changes.

Concern about Potential for Downstream Impact

FEMA also wants assurances that new gates will not negatively impact downstream residents. The City remains confident that downstream residents will not experience impacts. The purpose of the gates is to be able to pre-release water at a controlled rate before storms hit to minimize the volume going over the spillway. Also, the county is reportedly offering buyouts to vulnerable homeowners below the dam.

If the City cannot convince FEMA that the threat to downstream residents will not increase, the City will have to look for an alternative source of funding, such as adding a penny to water bills.

Next Steps on Additional Gates

Assuming Costello can convince FEMA that there will be no negative impact downstream, the next steps would be:

  • Final design
  • Permitting
  • Construction

Each phase could take six months to two years, depending on unforeseen obstacles, such as political headwinds and completion of the long-awaited San Jacinto River Basin Watershed Survey.

San Jacinto Watershed Survey Status

In March of last year, the SJRA proposed a new survey of the entire San Jacinto Watershed. Projects such as maintenance dredging, additional gates, and additional upstream detention, all depend on the outcome of this study.

To properly design gates, for instance, engineers need to know the volume of water they need to shed in a given period of time.

To properly design maintenance dredging, they also need to know how fast the river is and lake are silting up.

The estimated cost of this study was about $2 million. Consultants have been ready and waiting since last April for the green light. Unfortunately, FEMA went back and forth with the SJRA and its partners on this project for eight months. According to Costello, FEMA was ready to write the check in December when the Federal Government shut down.

Next Steps:

  • Deposit FEMA check
  • Execute study
  • Final report

Expect this one to take 18 months from the start date.

Need to Mitigate Mitigation Funding

The saga of this study epitomizes the need to improve disaster mitigation procedures. Flooding along the Gulf Coast is foreseeable. If we budgeted for it, we wouldn’t have to depend on Washington and could save years on these projects. Two million dollars is not a great amount of money when spread out among the two million people who would benefit.

It Took 6 Months to Win the War for Texas Independence

It’s taking twice that long for FEMA to cut a check.

Think we have lost our edge? We need to get proactive and self-reliant about these things if we want the region to grow. It’s already been a year and a half since Harvey. It will take another year and a half to complete the study. Three years before the serious work of actual mitigation begins! We can do better. We must demand that our leaders reform the way the mitigation business works.

As always, these represent my opinions on matters of public policy. They are protected by the First Amendment of the U.S. Constitution and the Anti-SLAPP statute of the Great State of Texas.

Posted by Bob Rehak on January 21, 2019

511 Days since Hurricane Harvey