Buffalo Bayou Erosion Control & Bank Stabilization – Harris County Toll Road Authority
LAN designed approximately 1,400 LF of erosion control and bank stabilization measures to protect the existing bridge columns for the Sam Houston Tollway. The erosion was due, in part, to sandy soil and turbulent conditions produced at the confluence of Buffalo Bayou and Rummel Creek, which occurs beneath the Sam Houston Tollway main lanes. Additional causes of erosion included extensive surface runoff and side-slope failures. The final design also included trail system expansion and landscaping with native vegetation and trees to give an aesthetically pleasing and natural appearance to this portion of Buffalo Bayou.
Erosion control measures included rock riprap, gabion walls, and blankets, and the maintenance zones collect storm runoff and prevent erosion to the top of bank areas. In addition, many of the existing trees and vegetation were maintained to minimize erosion. Channel lining with rock riprap was used to mitigate adverse impacts caused by the additional bridge width and change in low chord elevation.
Early in the design phase, LAN organized meetings with the Harris County Flood Control District (HCFCD), Harris County Storm Water Quality, and Harris County Permit Office to establish and agree upon permitting requirements. LAN obtained the necessary permits from the US Army Corps of Engineers (USACE) Galveston District, and coordinated with the district to establish procedures for limiting release rates from Addicks and Barker reservoirs during the construction phase.
At a glance
24- to 72-inch thick boulder rip rap
1,400 LF of erosion control and bank stabilization
$3.5 million construction cost
Coordination with six agencies
LAN identified four causes of erosion at this location
Associated with the expansion of the Sam Houston Tollway from three to five lanes
Erosion control measures were selected — and, in some cases, eliminated — based on their ability to be constructed cost-effectively and their potential impact on the environment.
LAN developed a construction strategy that preserved the natural habitat while improving overall water quality
LAN coordinated with the USACE to limit release rates from Addicks and Barker reservoirs during the construction phase
Harris County Toll Road Authority