THE MIND-BOGGLING UNDERGROUND MULTI-BAYOU TUNNEL DRAINAGE SYSTEM NOW PROPOSED FOR HARRIS COUNTY
The Harris County Flood Control District is considering digging the nation’s largestnetwork of high-volume tunnels 100 to 200 ft. underground to drain stormwater from several waterways, including — write the Chronicle‘s Mike Morris and Mihir Zaveri — Buffalo Bayou, White Oak Bayou, Hunting Bayou, Greens Bayou, Halls Bayou, Clear Creek, and Cypress Creek. “The goal under the plan,” they report, “would be for those waterways to be able to keep a 100-year storm event within their banks.” Flood czar Steve Costello argues that despite the project’s enormity, the tunnels might actually be the cheapestway to bring the all the county’s major waterways up to 100-year capacity. Even if such a one-shot solution does cost less than a series of smaller mitigation efforts, the pricetag for the tunnels would still be in the billions, or “perhaps $100 million per mile,” Costello says. On Tuesday, the Commissioners Court is set to vote on whether to pursue a contract with Fugro USA Land — a global engineering firm — for a feasibility study of the proposed project that would cost around $400,000. [Houston Chronicle ($)] Photo of Harvey flooding near UHD: Kelsie H. Dos Santos
FUNDING FOR DOWNTOWN HOUSTON’S NEW ISLAND
Houston’s flood czar Steve Costello tells the Chronicle’s Mike Morris that the city plans to apply for FEMA resiliency grants in order to build the North Canal Bypass — the long-whispered diversion channel that would relink White Oak and Buffalo bayous between Main and Elysian streets. The waterway concept bubbled up last year in Plan Downtown where its course formed an island northwest of Allen’s Landing indicated in the imagined map above. By bypassing the bayou’s oxbow, the channel is expected not only to reduce flooding downtown — it could also “help lower the water level in White Oak Bayou all the way to the 610 Loop and in Buffalo Bayou as far west as Gessner,” according to a county study. The result: “A little more than half of the 854 structures in the 100-year floodplain along White Oak and an adjacent tributary, Turkey Gully, would be removed from the floodplain.” [Houston Chronicle; previously on Swamplot] Map: Plan Downtown
With the completion of the once-missing link shown above, the paths lining Buffalo Bayou are now fully connected to the Heights Hike and Bike Trail. Making use of the new route, you can now ride all the way from Shepherd to Heights Mercantile — provided rising floodwaters have not blocked the path. The photo at top, snapped from the southern section of the Main St. bridge, shows a new railing along the path in place of the temporary fencing that lined the edge last year. Travis and Milam streets are visible in the distance in the second photo. The elevated building to the right of the path is part of UHD’s campus.
The purple curve on the map below marks the location of the new connection, while the gray line running northwest indicates the Heights Hike and Bike Trail:
COMMENT OF THE DAY: THE REAL REASON WHY BUFFALO BAYOU SMELLS AND LOOKS THE WAY IT DOES “If Buffalo Bayou stunk so much, then no one would have built a bunch of expensive homes all along it (west of downtown). Most of the Houston area’s waste water effluent flows into the Bayou east of downtown anyways. The Clinton/69th plant (the largest in the city) is just east of downtown, and the Sims and Braes plants don’t enter until well past downtown. With that said, I don’t think the treatment plants are the big contributors to the overall unpleasantness of the Buffalo Bayou water (flood events not withstanding). Most of the effluent (when the plants are properly operating) is nearly clear and usually only has an ‘earthy’ odor to it if any at all. I think the big issue with the bayou’s water quality is the regular runoff and trash that flows into it and eventually lines the shores of it all along downtown.” [nmj, commenting on The North Canal, a New Downtown Island, and Other Secret Plans for Downtown Houston’s Future] Photo: Swamplot inbox
Construction is almost complete on a missing link between the bike paths lining Buffalo Bayou Park and the Heights Hike and Bike Trail,according to passer-by Christopher Andrews — who snapped the above photo from the southern span of the Main St. bridge, looking towards the back of the UH–Downtown campus. The purple curve just north of Allen’s Landing marked on the map below is the segment of the bayou trail that’s in the works. You can see where that portion will intersect the Heights trail, marked below in gray, after it crosses White Oak Bayou’s southerly meander to the east of UHD:
More new features are imagined for the center of Houston than just the new Green Loop highlighted in the just-released Plan Downtown proposal. There’s also a mysterious new Downtown island. Where did it come from?
It’s the result of digging the long-whispered North Canal Channel Bypass, a re-linking of White Oak and Buffalo Bayous north of Downtown. Existing bends and narrow banks along the 2 bayous just east of Main St. restrict the flow of stormwater during flooding events. According to reports, engineering studies have estimated that cutting a straighter diversion channel to bypass the oxbow could reduce flooding Downtown by 3.5 ft.
But digging a new canal while maintaining the existing path of the bayou would create an island out of the area just north of Commerce St. An imagined map of the area in Plan Downtown’s report (rotated so North is aimed down and to the right) shows what car and pedestrian bridges might link it to the mainland:
It’s coming a little late for many homes in Meyerland, but excavation crews are once again at work widening the segment of Brays Bayou just downstream of that flooded neighborhood. Work on the segment between Buffalo Speedway and S. Rice Ave.began this past summer. The widening is a part of the decade-plus-old Project Brays, begun before but accelerated as a result of flooding during Tropical Storm Allison in 2001.
Water levels on the bayou have returned to a manageable level; this photo, sent in by a Swamplot reader, shows an excavator at work on its south bank just west of the inlet between Timberside Dr. and Bevlyn Dr.
The retreat of floodwaters has revealed the extent of the silt that Harvey-triggered flooding deposited along Buffalo Bayou. A beachgoing reader sends Swamplot these pics of the new dust-colored landscapes that have taken shape along Buffalo Bayou Park and adjacent former green spaces.
The silt-covered bench shown above sits across Buffalo Bayou from the Houston Police Officers Memorial, near Glenwood Cemetery. Here’s a view from further back:
The Galveston District of the U.S. Army Corps of Engineers has made public a set of interactive maps — normally used by emergency personnel — that show which areas along the length of Buffalo Bayou are predicted to remain under water or emerge from it as officials continue to release water from the Addicks and Barker reservoirs upstream. Individual interactive map panels cover each day from September 5th through the 16th, but as of this date all rely on data developed on Tuesday, when the maps were created.
The embedded version above mimics the view from a mobile browser; you can zoom in to view the projected water line on any street. To switch days, click on one side or the other of the panel at the bottom of the frame — or choose the date directly from the menu that appears after you click on the icon in the top left corner.
To view the map in its own browser window, click here.