Let’s get the word out!
By Mark Marienfeld, P.E.
I have been watching the TV news coverage of the flooding in the Midwest these past few days. What I see is unprecedented, I believe: TV reports showing the use of geotextiles for temporary flood-control dike building. As background, for those not familiar with the application, this is a geotextile laid out on the ground where a raised dike is needed and an earthen berm, up to 5-7ft high is placed partially onto the geotextile along its horizontal direction. Then, the geotextile is folded back over the berm material and a few sandbags are placed to hold the geotextile wrapping in place. The result is the construction of long, geotextile-covered temporary dikes to stop rising floodwaters. The advantage is rapid construction, compared to piling thousands of sandbags; furthermore, this system is removed quickly and cleanly after the flood. The continuity of the geotextile-wrapped berm is also extremely resistant to local shifting or movement—the downfall of many berms constructed with small, individual sandbags.
I just watched a TV story about a reconstructed emergency dike made with a geotextile, with just a few sandbags used to hold down the geotextile draped over the berm. The reporter stated that there were literally miles of this “plastic sheeting” being installed, and then he went on to talk about “sandbags,” a term with which we have all become very familiar. If this “plastic sheeting” was correctly called a “geotextile” by all the news coverage, the entire country would know what a geotextile is—including those in Washington, D.C., to whom we are currently trying to lobby all the benefits of geosynthetics.
I feel we have a tremendous opportunity to get the word out about the use of geotextiles for this purpose. We should tell the story of how much more quickly installed, structurally efficient, and environmentally friendly this system is compared to the old sandbag methods. I believe that the use of geotextiles for this application still represents only a small amount of emergency dike building, but its use would grow rapidly if this information gets out.
Any coverage we get could also state that the largest application for geotextiles is actually for underneath roads “where smart transportation officials have recognized its benefit in separating and stabilizing the road structure from the soil below, saving thousands of dollars in every mile of road and making the road last much longer.” And, maybe we could get a plug in for the American textile industry and specifically GMA, where there is more information at gmanow.com.
The point is to get the term “geotextile” known to everyone.
As a follow-up, I believe the EPA should address the problem associated with the removal of sandbags after floods recede. Sandbag removal is hard, anti-climatic work done without the enthusiasm and adrenaline that is apparent in the building of sandbag dikes. We all know these bags are made from low-end fabrics without much strength or UV protection and, I would suspect, many of them ultimately just fall apart, with the yarns causing subsequent damage to wildlife and the environment. So, if the EPA does not mandate the timely removal of sandbags, they should, and then local emergency agencies would have more incentive to look for an alternative, such as geotextile-wrapped berms.
I also saw TV footage showing a geotextile placed onto the side of an existing levee where the encroaching water had the potential of eroding a breach at the top of the levee. This is a very good concept as well but unfortunately, in the scenes I saw, the geotextile was not anchored well and erosion was still a threat. This is also an opportunity to state how properly toed-in and anchored geotextiles and durable erosion-control products are helping to maintain the integrity of existing levees against the piping and erosive forces of rising floodwaters.
Anyway, I hope this does not sound like the rantings of a semi-retired geo-guy, but I was excited to finally see the geotextile- wrapped berms on TV since I was involved in the development of this system several years ago.