As a Civil Engineer I have done numerous erosion projects albeit none on the beach, but all with similarities to the one mentioned in the study. There are a few different ways to design a solution and even more ways to interpret the intent of those solutions once they are in place. Most people want hard solutions, i.e. concrete and steel, when their property is threatened by erosion, be it on the bank of a stream, or abutting the beach. They want to see something physically protecting their investment. Structures such as seawalls or lined channels are always very strongly stated short term solutions. They almost always cause more problems then they solve; just look at New Orleans. Nature has a way of reclaiming its property. Erosion occurs for basically two reasons, one is just the natural process of time as you can see in the grand canyon and the other is caused human intrusion. Nature tends to take millions of years while human caused erosion can take a very short time. Concrete and steel can be thought of as just adding more human intrusion in the mix and thus causing more long term problems. Letting nature take its course will inevitably remove the offending human intrusion of houses on dunes or paving over fields, and the end results are usually not acceptable to the property owners. Correct usage of soft structures such as geotube, geofabrics etc. is an attempt to help nature mend with the results that are desired by the community. They are generally put in as temporary measures with a long term goal of helping naturally occurring plants reestablish and secure the eroding soils. The plants and accompanying root structure armor the dunes, stream banks etc. These type projects are long term solutions, but also require a longer time for the plants to reestablish to the point of fully stabilizing the repair. There are also plenty of people out there that will put in a soft structure as if it were a piece of concrete, that is, without the long term goal of restoration in mind?only the short term protection in mind. If you go back through the report and look at the photographs you will notice that the geotubes in the study did help to prevent a lot of undercutting of the dunes, and probably have helped to keep the area in a better position for a quicker recovery and to continue to build back the dunes.
I am not about to say that geotubes are the only way to accomplish beach restoration. Grayton had good results with the sand fence and sea oats program. Ultimately that would provide a more or less all natural solution, but it takes a long time. Not building houses on the beach or dunes would be a good step too, but probably not one that property owners, nor vacationers, would like. Generally speaking if the funds can be devoted to developing a good solution rather than funding legal fights everyone wins. Regional solutions that allow a comprehensive approach are often better than a confederacy of projects where one undermines the other.
