Feb 14, 2012
Contact: Ken or Kate Gooderham, ASBPA executive directors -- (239) 489-2616
Harry Simmons, ASBPA president -- (910) 200-7867
Beaches Q&A, part 1
The first in a series of frequently asked questions concerning common coastal issues
QUESTION: Why do beaches erode?
ANSWER: The simple answer is they do not have enough sand. However, the causes are different in different parts of the country. On the West Coast, beaches are sand starved when river dams block the flow of sand. Eastern beaches often lack sand because inlets or navigation projects interrupt sand’s along-shore movement. All beaches suffer from storms and other natural events that cause erosion. Things as disparate as storm-driven waves or a simple change in an offshore sandbar may cause one coastal area to lose sand while another gains.
QUESTION: Why do coastlines have to be “managed”?
ANSWER: Well, they don’t have to be… but the alternative is they’ll move around wherever winds and waves (and other forces) push them. That works on uninhabited and unimproved islands – of which there are fewer and fewer. Put in some buildings, roads, sewer pipes and power lines, and all of the sudden a wandering shoreline can become a problem. Sometimes, people deal with that problem on a site-by-site basis… which can work for a while but can often have negative impacts on adjacent properties. (The rip-rap you put in on your beach will protect your upland structure, but will cause the property downdrift from yours to erode even faster.) Because of this, many communities finally decide that coastal issues need to be addressed as a system – not a collection of individual fixes, but something that works for the larger shoreline area. That’s the start of coastal management.
QUESTION: Is beach restoration – pumping sand from other sites onto the beach – the only solution?
ANSWER: Depends on the state of your shoreline. If overall there’s plenty of sand in your coastal system and you just need to work on isolated “hot spots” of erosion, there may be small-scale solutions that will solve the problem. However, if your erosion issues are long-term and significant, your choices are limited to three options: Add more sand, build a hard line to stop erosion (and probably lose the sandy beach), or pack up and move back from the waves.
QUESTION: Why are hard structures – seawalls, revetments, etc. – a bad choice?
ANSWER: Structures are a choice… whether or not they’re bad is a decision each community needs to make. Many areas have moved away from using seawalls and revetments to control coastal erosion because of the rapid loss of sandy beaches seaward of the hard structures, when erosion continues and no new sand comes into the system in front of the structure. When they’re used along a stretch of shoreline – what is called “armoring” – that shoreline is fixed in place but the lack of sand means a lack of beaches. Upland properties are protected (unless the structures fail, which can happen in storms), but the natural beach is gone – with the resulting loss of habitat, recreational area and distance from storm-driven waves.
However, some coastal engineers are now bringing back hard structures on a small scale – as a way to address very specific erosional hot spots or as part of a larger restoration project where the structures are engineered into the overall design of the beach and its performance in years to come.
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ABOUT ASBPA: Founded in 1926, the ASBPA promotes the integration of science, policies and actions that maintain, protect and enhance the coasts of America. For more information on ASBPA, go to www.asbpa.org, facebook or www.twitter.com/asbpa.