Public Meeting: Bridges and Meander Bypasses on Buffalo Bayou

Date is Oct. 17 to Find Out Study Results

And More

Oct. 13, 2019

 

In the wake of disastrous flooding along Buffalo Bayou during and after Harvey in 2017, particularly on upper Buffalo Bayou after the opening of the floodgates on the federal dams, some west Houston residents urged the Harris County Flood Control District to look into whether meanders downstream and bridges across the bayou had blocked the flow, causing them to flood.

In response, using up to $350,000 in public funding from the 2018 Flood Bond election, the District in November of 2018 hired the engineering firm Huitt-Zollars to study the thirty-three bridges and four pipelines that cross the bayou between Highway 6 at Barker Dam and Congress Street some twenty-six miles downstream in downtown Houston.

More controversially, the study also examined the possibility of constructing bypass channels or culverts in thirteen locations, cutting through natural bends in the river. This would be below Beltway 8 where the bayou twists and turns, as rivers naturally do, for good reason. (p. 36) Meandering streams are longer and carry more water. Meanders also help dissipate the force of the stream during floods. Such is the power of the underlying geology that even if altered or straightened, rivers will seek to return to their natural channel, breaking through concrete if necessary. (See Tropical Storm Allison, Tranquility Garage, 2001.)

In the 1960s, environmentally-minded property owners on the bayou, including Terry Hershey and Save Buffalo Bayou’s founding president, Frank Smith, joined forces to stop the Corps of Engineers from stripping, straightening and covering in concrete this winding, wooded stretch of the bayou—as the Corps had done earlier, destroying White Oak and Brays bayous.

The Flood Control District is holding a public meeting to discuss the results of the meanders and bridges study on Thursday, Oct. 17, from 6 to 8 p.m. at the Memorial Drive Presbyterian Church, 11612 Memorial Drive, in Houston 77024.

 

Comparison of Buffalo Bayou at Beltway 8 in 1944 and during Harvey in 2017. Note the engineered channel bypassing the original meander and flooding along the oxbow remnant. Graphic by Diane Masterson

 

Maligning Meanders

In the early morning of Aug. 28, 2017, after the peak of the flooding from Harvey had passed downstream on Buffalo Bayou, the Corps of Engineers made the unprecedented decision to open the floodgates on Barker and Addicks dams in far west Houston. Rising water flowing from the rapidly developing north and west of the city threatened to overwhelm the earthen dams. When the gates were opened, residents living along the six-mile plus channelized stretch of the bayou just below the dams were badly flooded. This stretch of the river had been narrowed and straightened by the Corps in the Fifties, essentially reducing its capacity.

But a popular belief continues that the meanders below Beltway 8 caused the bayou to backup and flood homes upstream adjacent to what is now Terry Hershey Park, hence the push to construct channels to bypass or cut through meanders. (Another popular belief, which also persists, is that the “rich people downstream” did not flood. There was, of course, massive flooding along Buffalo Bayou all the way through downtown Houston during Harvey. But that flooding, fed by the rapid accumulation of rain runoff from the city and suburbs below the dams, occurred before the floodgates were opened.)

In October of 2018 Save Buffalo Bayou published a report in response to this widespread mistaken belief about meanders downstream. The report explained why people flooded upstream and how meanders are beneficial and actually reduce flooding. You can read the full report here.

Read the rest of this post.

Leave a Reply

Your email address will not be published.