Hard vs. Soft Solutions for Coastal Erosion
Waterfront property remains desirable for homes, condos, hotels, restaurants and office buildings. But growing threats from winter storms and rising sea levels from climate change are hastening the erosion of coastal property, leaving real estate investors and property managers to question the most environmentally friendly and cost effective approach to erosion control.Solutions are available and in terms of beach erosion, a number of options exist under the categories of “hard” and “soft” engineering solutions. The general consensus is that soft erosion control can better protect properties than can hard solutions, and from a regulatory point of view, better protect the beach fronting the property from erosion both in terms of shielding the property and also regarding coastal resiliency. In a nutshell, soft solutions are natural and may include fabrics, beach nourishment, beach dewatering systems, sand bags and specialty products. Hard solutions involve rock, concrete and steel, thereby increasing the potential of damage to beachfront properties due to wave reflection off of such hard structures.Rock structures, such as rock revetments, walls and breakwaters represent the traditional approach to shoreline and coastal protection and like sheet pile walls and geo tubes, provide a high degree of protection against strong storm conditions. That said, there is growing concern among coastal engineering professionals that hard measures may be accelerating erosion due to increased wave reflection and/or the impact these structures have on altering natural shoreline processes.The most significant disadvantages to hard solutions is beach deficit, the probable negative effect on adjacent beaches and potential loss of a recreational resource. In terms of cost, hard solutions are many times more expensive and still require periodic maintenance.These concerns have led to a growing tendency toward “soft” engineering measures to control and stabilize beach erosion through the use of biodegradable materials such as jute and coir products. The most common application is the fabrication of coir (a natural fiber extracted from the husk of coconut) mats into large envelopes and bags which are then filled with locally compatible beach sand and constructed into terraces extending up the face of the coastal bank. These soft materials absorb wave and surf impacts, help encourage sand to build up or accrete naturally and fosters reduced wave reflection. Coir envelopes can be planted with locally indigenous vegetation to restore coastal banks; and since those materials are in original vegetated condition they provide benefits for bird and wildlife habitats, in addition to being ecologically friendly.Coir envelope coastal bank stabilization programs have been known to slow down the rate of erosion. Placing beach compatible sand on coir envelopes at the same volume that would be taken by wave and surf action during the course of a year can result in a shoreline protection program that absorbs rather than reflects wave energy, is more compatible with the existing shoreline dunes and coastal bank, and continues to supply sand for on-shore/near shore coastal processes.The primary drawback to soft solutions is that they are more temporary in nature and while the initial cost is relatively low, ongoing replenishments is required. New solutions from around the globe are being developed and coming to market as countries around the world share a common threat of coastal erosion.Climate change, rising sea levels and human interference in the form of buildout can create a perfect storm for beach erosion, but solutions are available to help quell some of the ravages of time.
David Lager is CEO of NETCO (www.netcomanage.com), a coastal erosion/project management firm.