Erosion Control and Hydraulic Performance

Rainfall Erosion Control Testing on ClosureTurf™

Rainfall Erosion Control Testing on ClosureTurf®

Rainfall Erosion Control Testing

The ClosureTurf® System was tested for performance against rainfall-induced erosion in accordance with ASTM 6459. ClosureTurf® stood up to a rainfall intensity of over 6.5 in/hr with only 0.04% loss of the sand infill. The typical design criterion for sediment runoff on a traditional landfill soil cover is 3 tons/acre/year. The measured loss of sand infill (0.04%) of the ClosureTurf® is approximately 0.03 tons/acre for a 6.5 in/hr rainfall intensity. Using ClosureTurf® will significantly reduce sediment loads and runoff turbidity. Also, the ClosureTurf® System filters the storm water and provides “clean” runoff.

Steady State Hydraulic Testing of HydroTurf® at CSU

Steady State Hydraulic Testing of HydroTurf® at CSU

Large Scale Flume Testing of HydroTurf®

In areas of channelized flow (bench drains, downchutes, and perimeter channels), Watershed Geosynthetics suggests that the ClosureTurf® be infilled with HydroBinder® instead of sand. We refer to the resulting product as HydroTurf®.

HydroTurf® has been extensively tested at Colorado State University Engineering Research Center(CSU). CSU tested it in accordance with ASTM D 7277 – Standard Test Method for Performance Testing of Articulated Concrete Block (ACB) Revetment Systems for Hydraulic Stability in Open Channel Flow. The results of the testing were analyzed in accordance with ASTM D 7276 – Standard Guide for Analysis and Interpretation of Test Data for Articulating Concrete Block (ACB) Revetment Systems in Open Channel Flow. Testing was performed to the 5-ft overtop flume capacity which resulted in over 29 fps in velocity. At this flow, there was no instability, deformation, loss of intimate contact, or damage of the HydroTurf® system, and there was no erosion of the underlying subgrade.

Wave Overtop Hydraulic Testing of HydroTurf® at CSU

Wave Overtop Hydraulic Testing of HydroTurf® at CSU

Full-scale Wave Overtopping Testing for Levee Landward Side Slope Protection was also performed on the HydroTurf® at CSU. CSU has the worldʼs largest Wave Overtopping Simulator which they developed for the US Army Corp of Engineers. Testing was performed up to the maximum capacity of the simulator (4.0 cfs/ft which represents a generic hurricane with a 0.2 percent annual exceedance probability – 500 year event).

Additional detailed information concerning the performance of HydroTurf® can be on the HydroTurf® Performance page of our website.

Critical Slope Length Diagram

Critical Slope Length Diagram

Critical Slope Length

The critical slope length is defined as the length of overland flow where the sand infill of the ClosureTurf® stays in place. HydroTurf® bench drains and channels should be used at distances that are less than the critical slope length so that the runoff is channelized prior to movement of the sand infill. Upon request, Watershed Geosynthetics is able to provide sample calculations for critical slope length.