Since 2000, Harris County Flood Control District (HCFCD) and its partners have spent more than a half billion dollars to reduce flooding in the White Oak Bayou watershed. And they aren’t done yet. Before the flood bond is complete, they will have spent at least $575 million to create detention basins, widen channels and make other improvements.

On 7/19/2022, I flew up White Oak Bayou in a helicopter with Bill Calligari and Ken Williams, two fellow members from the Harris County Community Flood Resilience Task Force. Our goal: to learn what the money bought.

This is the second of four posts. The first covered Greens Bayou. The next two will cover Hunting and Halls Bayous.

White Oak Bayou by the Numbers

White Oak Bayou is Harris County’s sixth largest watershed but its third most populous. 51% of its residents qualify as Low-to-Moderate Income (LMI). It’s our fourth most densely populated watershed (people/square mile). Not surprisingly it had the third most damage in 5 major storms since 2000 (Allison, Tax Day, Memorial Day, Harvey, Imelda). The storms damaged 25,739 structures. Look at some of the photos below of structures crowding the bayou and you will understand why.

White Oak Bayou from the Air

White Oak Bayou flows southeast from its headwaters northwest of FM 1960 to its confluence with Buffalo Bayou near downtown Houston. The watershed comprises 111 square miles, with 146 miles of open streams. They include:

• White Oak Bayou
• Little White Oak Bayou
• Brickhouse Gully
• Cole Creek
• Vogel Creek

Our helicopter started the White Oak leg of our flight near the Heights north of downtown. From there, we flew upstream. This is what the Heights looks like from the air – a study in population density which correlates highly with flood damage.

The lower section of the bayou needs repairs according to HCFCD. The Army Corps straightened, widened and partially concreted lower White Oak upstream approximately to West Tidwell Road between 1964 and 1971. See below.

HCFCD now maintains White Oak and has observed a number of locations where concrete is approaching the end of its useful life.

16 Other Projects in Works

HCFCD currently lists 16 other projects in the White Oak watershed.

Some projects are still being studied. Some are complete or nearly so. As of June 8, 2022, HCFCD was working out a contractor issue on the largest project, which will delay the originally scheduled completion this summer.

Federal Flood Damage Reduction Project

The largest project is the White Oak Bayou Federal Flood Damage Reduction Project. This $124 million project will substantially reduce flooding risks along White Oak Bayou. It started in 1998 in partnership with the U.S. Army Corps of Engineers, with the Flood Control District designated as the lead. The two segments of the project are fully funded to completion.

Limits of downstream segment of Federal Project

They include:

• Construction of approximately 15.4 miles of channel conveyance improvements along the bayou from FM 1960 to Cole Creek near West Tidwell in the two segments above.
• Excavation of six stormwater detention basins to hold almost one billion gallons of stormwater. That’s enough to hold a foot of rain falling across almost 5 square miles.
• Construction of the Jersey Village Bypass Channel

Upon completion, HCFCD estimates that most parts of the project area will see water surface elevation reductions of 0.1 to 1.8 feet for a 1 percent annual chance (100-year) flooding event.

HCFCD

Many smaller detention ponds like those above now line both sides of the bayou and its tributaries from upstream to down.

Arbor Oaks Subdivision Buyout

Since 2003, HCFCD has bought out more than 200 homes in the Arbor Oaks subdivision. It is still buying more on either side of Vogel Creek to build a 431 acre-foot stormwater detention basin and restore the floodplain. That would hold a foot of rain falling over 2/3rds of a square mile.

Acquisition costs in such densely populated neighborhoods can easily exceed construction costs.

This part of the White Oak story dramatizes how costly, difficult and time-consuming it can be to buy out and mitigate areas built in floodplains.

Here’s what part of it looks like from a few hundred feet up.

Many Other Projects

There are so many other projects underway on White Oak that I scarcely have room to mention them. See my previous post that discusses conversion of the Inwood Golf Course to a series of 12 connected detention ponds. It will hold 1200 acre feet. That’s a foot of rain falling over 2 square miles.

Then there’s the Woodland Trails Detention project downstream from Fairbanks N. Houston Road. It’s budgeted at $63.5 million. But it’s still in right-of-way acquisition.

And then there’s the North Canal near downtown. HCFCD and the City of Houston are working to finalize an interlocal agreement. Grant funding calls for completion of the first phase of the project by May 2023.

Finally, don’t forget the detention basins and channel conveyance improvements on tributaries, such as Little White Oak Bayou and Brickhouse Gully.

They all add up to more than a half billion dollars…and counting! Water needs somewhere to go during a storm. If we don’t leave a floodplain for floodwaters to safely expand, they will wind up in peoples’ living rooms.

Posted by Bob Rehak on 7/20/2022

1786 Days since Hurricane Harvey