Producer/Manufacturer: Propex Geosynthetics
Primary Use: Main Fabric
Producer/Manufacturer: Propex Geosynthetics
Primary Use: Secondary Fabric
Engineer Company 1
Jones Carter & Propex
Please describe the project specifications
Brookshire-Katy Drainage District (BKDD) maintains a drainage channel that runs along Stalknecht Road in Waller County Texas. Extreme storm water flows caused by Hurricane Harvey caused the roadside drainage ditch to experience erosion and slope instability, reducing the channel’s capacity.
The severe erosion and reduction in channel capacity prompted BKDD to pursue permanent erosion protection. An early phase in the design process used rock-filled gabion baskets to armor the channel, however, the design engineer wanted a more economical and environmentally-friendly solution.
Stakeholders selected SCOURLOK® for the remaining phases of the project because it was a more cost-effective solution. SCOURLOK is a stabilization system that features rigid and interlocking cells armored with erosion protection from a highly UV stabilized High-Performance Turf Reinforcement Mat (HPTRM). The gravity wall system is engineered for applications that require toe and scour protection and provides geotechnical stability and soil retention to support sediment control and withstand intense hydraulic flows.
The design included an eight-foot wall comprised of two tiers of SCOURLOK that spans 500 feet along the eastern side of the channel. The bottom tier was constructed with two rows of SCOURLOK that were embedded three feet to protect against undermining and included an internal sand layer to provide relief from potential pore pressure build-up. The top tier consisted of a single SCOURLOK row filled on-site soils.
The design also included 300 square yards of ARMORMAX® along the channel side slope above the SCOURLOK to provide additional erosion protection. ARMORMAX is a solution for controlling erosion and stabilizing slopes adjacent to water, steep slopes with potential for shallow plane failure, and wave action. The system is composed of Engineered Earth Anchors that are designed and tested for compatibility and performance with High-Performance Turf Reinforcement Mat (HPTRM) to promote vegetation and increase slope stability for up to 75 years.
The severe erosion and reduction in channel capacity prompted BKDD to pursue permanent erosion protection and slope stabilization. An early phase in the design process used rock-filled gabion baskets to armor the channel, however, the design engineer wanted a more economical and environmentally-friendly solution.
Work under this contract included the following:
• Installation of construction entrances and Storm Water
• Pollution Prevention Features Repair of eroded side slopes
• Excavation for construction of drainage structures
• Establishment of vegetation in disturbed areas
• Restoration of all disturbed areas
What is unique or complex about the project?
An early phase in the design process used rock-filled gabion baskets to armor the channel, however, rock in the Texas gulf coast region is not readily available. Rock was transported to the site by rail car from hundreds of miles away, significantly increasing transportation costs and slowing the installation process. SCOURLOK® allows the reuse of on-site soil to fill the units. This reduces installation costs and drastically reduces the amount of carbon emissions from transportation.
Replacing rock-filled gabions with SCOURLOK and ARMORMAX also helped reduce the project's overall carbon footprint. The HPTRM component of both systems has a verified carbon footprint of 2.7 kgCO2e per 1m2 of material. Comparatively, the carbon footprint of rock riprap alternatives are up to 30 times higher. Once installed, these systems help to decrease sedimentation and pollutants and encourage infiltration of water back into the groundwater table. These are two reasons why the EPA has identified systems that utilize HPTRMs technology as a Best Management Practice (BMP) for improving water quality
SCOURLOK provides a vegetated gravity wall system that will resist sliding and overturning for up to 75 years. The combination of SCOURLOK and ARMORMAX has successfully mitigated flooding and stabilized Harvey Channel. Additionally, vegetation has established, providing an environmentally friendly and effective prevention of erosion and sediment runoff.
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