Greens Bayou Detention Basin Capacity Steadily Growing
Harris County Flood Control District (HCFCD) and its partners continue to add detention basin capacity along Greens Bayou to reduce the risk of flooding. I flew in a helicopter today with fellow Harris County Community Flood Resilience Task Force members Ken Willians and Bill Calligari. We flew over Greens, Halls, Hunting, and White Oak Bayous. In this post, let’s focus on what we found in Greens.
From west to east, we flew over the Cutten Basin at 249 and Beltway 8, then followed the bayou over the Antoine, Kuykendahl, Glen Forest, Aldine-Westfield, and Lauder Basins. Some have recently completed construction. Others are still under construction. Here’s a rundown of everything between US249 and US59 along Greens.
Scheduled for completion later this year, the Cutten Basin covers approximately 250 acres. It includes five compartments, four south of Greens Bayou and one north. When complete, it will hold 850 acre feet of stormwater. That’s enough to hold a foot of rain falling across approximately 1.3 square miles. It will lower the water surface elevation along Greens by a third of a foot in a hundred-year flood.
HCFCD and the Army Corps started the $80 million Antoine Basin in 2015. The Army Corps designed and built it. Satellite photos in Google Earth first show it holding water in November 2020.
The completed basin holds approximately 1,650 acre-feet, or 538 million gallons of stormwater. To put that in perspective, it holds a foot of rain falling over a 2.5 square mile area, or half a foot falling across 5 square miles!
Kuykendahl Stormwater Detention Basin sits on a 288-acre property near Kuykendahl Road and Ella Boulevard along an unnamed tributary of Greens Bayou. In floods, it holds water back from entering the bayou and then releases it safely and slowly after the storm has passed.
Contractors removed 3.61 million cubic yards of soil from the site. It holds 2,325 acre-feet, or 757.6 million gallons of stormwater. That’s a foot of rain falling across 3.6 square miles, or half a foot falling across 7.2.
Following construction, contractors planted 22.19 acres of native tree and shrubs, and 12.79 acres of stormwater quality-treatment wetlands. They also created 14.04 acres of other wetlands to replace those impacted by construction.
Ceres Environmental Services Inc. constructed the Kuykendahl basin and another to the east (see Glen Forest below). Combined, they were the largest construction contract ever managed by HCFCD up to that time. The two basins reduced or removed flooding risks and damages from more than 1,100 structures along Greens Bayou. “Avoided damages” exceed $90 million in every flood. Far more than the cost of construction.
FEMA awarded $39.2 million to the Harris County Flood Control District, under the Hurricane Ike Hazard Mitigation Grant Program (HMGP) to construct the basins and HCFCD contributed matching funds.
Google Earth satellite photos indicate construction finished for both basins in 2020.
Farther east along Greens, the Glen Forest Detention Basin extends from I-45 to Imperial Valley north of Greens Road.
The Glen Forest Basin project removed approximately 2.15 million cubic yards of soil in three connected cells. The completed basin holds approximately 894 acre-feet. That’s 1.4 square miles one foot deep or 2.8 square miles a half foot deep.
Aldine Westfield Basins: Phases 1 and 2
Farther east along Greens Bayou, directly south of Houston’s Bush Intercontinental Airport, you will find two more new basins. HCFCD completed construction on the first in April 2021. The second (to the north) then began construction and has not yet finished.
Phase 1 holds approximately 667 acre-feet of stormwater and Phase II will hold another 600 acre-feet. Two 5’x4′ reinforced concrete boxes will connect the two phases and outfalls into Greens Bayou.
Together the two basins will hold a foot of rain falling over more than two square miles.
1.5 miles to south of the Aldine-Westfield Basins, you will find the Lauder Basin: Phases 1 and 2.
Phase 2 of the Lauder Basin is starting in the forested area in the upper right of the photo above.
Phase 1 completed construction late last year. In May of 2022, the Texas Water Development Board granted HCFCD more than $2.2 million to begin Phase 2.
The two basins when complete in 2024 will hold a foot of rain falling over more than 2 square miles (1260 acre feet). That concludes your helicopter flight down Greens Bayou for today.
Greens by the Numbers
Together, these basins should hold approximately a foot of rain falling over 12 square miles.
That’s not enough to prevent flooding in another Harvey. But it will certainly reduce flooding for thousands of people. HCFCD has not yet released updated flood-risk data for the mid- and upper reaches of Greens Bayou (shown above). More news on that when it becomes available.
According to data obtained from HCFCD via a FOIA Request, Flood Control and its partners have spent more than $435 million on flood mitigation in Greens Bayou between 1/1/2000 and the end of last year. That includes money spent on all phases of all projects shown above.
Only three other watersheds have received more funding since 2000: Brays, White Oak and Sims. But more on those later.
Greens was the second most heavily damaged watershed in five major storms (Allison, Tax Day, Memorial Day, Harvey, Imelda). Those storms damaged more than 29,000 Greens structures.
58% of the population of Greens has low-to-moderate income (LMI). That ranks 6th on the LMI scale of Harris County watersheds.
Posted Bob Rehak on 7/19/22
1785 Days since Hurricane Harvey