“Different materials to protect canal liners had been tried in irrigation canals across the West over the past 15 or 20 years. One typical method uses a low cost earthen material like clay. Over time, however, these systems begin to crack and start to leak. It’s not a very efficient way to convey water,” notes Joe Kaul, Kaul Corporation, Presto Geosystems’ Western States represen‐ tative and geosynthetics supplier.
Usbor Testing Performance
A 10‐year canal lining study by the US Bureau of Reclamation (USBOR) tested four canal types for a multitude of fac‐ tors including construction and maintnenace costs, durability, and effectiveness against seepage reduction. One of the tested categories, “geomembranes with a concrete cover” offered the highest long‐term performance results.
The Geoweb Solution
Kaul introduced the concrete‐filled 3D GEOWEB system to the USBOR as an effective geomembrane cover solution. With over 30 years of proven success protecting geomembranes, Kaul was confident they could design and construct a better long‐term solution with the GEOWEB system.
Gary Kennedy, Superintendent with the Mancos Water Conservancy District in Colorado noted that the region had been rehabilitating their canal systems for a number of years. Regular lining material with a shotcrete cover was considered as well as individual con‐ crete tiles for several sites. Ultimately, the concrete‐filled GEOWEB solution was chosen as it would offer the best protection from expansion and contraction issues caused by freeze‐thaw cycles and reduce long‐term maintenance costs.
The Flexible Mat Solution
Unlike typical reinforced concrete where whole sections can crack and uplift, the flexible nature of the GEOWEB system allows it to flex and conform to minor subgrade movement. Concrete cracks are controlled along the line of the GEOWEB cell walls. With the proven success of the GEOWEB system as part of a “geosynthetics” solution (geotextile, geomembrane, GEOWEB geocells), the USBOR and Bureau of Land Management (BLM) see opportunities to incorporate this solution in more of their irrigation canals.