Monday, October 7, 2013

Preventing Beach Erosion

Introducing a new question and answer column at Home Science called EarthTalk.

Dear EarthTalk: What are some steps we can all take to prevent beach erosion?  --Kyle Phillips, via e-mail.

Beach erosion is a huge issue for coastal areas in the U.S. and elsewhere. According to the non-profit American Shore & Beach Preservation Association (ASBPA), all beaches endure storms and other natural disturbances that cause them to lose sand, but the causes of beach erosion are not always the same. “On the West Coast, beaches are sand-starved when river dams block the flow of sand,” the group reports. That contrasts with Eastern beaches, they say, which often lack sand because inlets or navigation projects interrupt the movement of sand along the shore. “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.”

“Ultimately, a beach erodes because the supply of sand to the beach can not keep up with the loss of sand to the sea,” says Ken Rubin, Assistant Professor of Geology and Geophysics at the University of Hawaii. “Most sand is transported from inland via rivers and streams. The damming of most waterways in the U.S. has thus prevented a major supply of sand from getting to our beaches.”

Soil Science at North Carolina State, via Flickr
He adds that beach erosion can be exaggerated during periods of rapid sea level rise, such as that which we are expected to experience soon as a result of global warming melting the polar ice caps. “When the encroaching sea comes against people’s property, the tendency is for people to try and stop the encroaching sea,” Rubin reports. “They armor the shoreline with seawalls, revetments, jetties, etc. [which] have a negative effect on beaches because once sea water reaches them, it ‘bounces’ off them with more energy than a wave washing back off a normal sand beach.” The result is that more sand is carried off shore, promoting additional beach loss. And the increased severity and frequency of storms due to climate change only serves to further stir up the remaining sand at many beaches.

Unfortunately, beyond keeping our carbon footprints in check, there isn’t much that individuals can do to prevent beach erosion. Building bulkheads in front of individual homes, or along entire beachfronts, may provide some short-term relief from beach erosion, but as often as not these actions can cause worse problems in the long run. And land use regulations that require homes and buildings to be built with a big buffer zone to the beach can go a long way toward protecting personal property and home values in coastal areas, but they won’t help prevent beach erosion.

According to ASBPA, physically adding sand to beaches to replace losses is really the best fix: “Coastal scientists have years of experience with beach restoration projects and have learned that adding sand in the right quantities, properly engineered and maintained, can make a beach last forever.”

Of course the best solution to any problem, including beach erosion, is to address the causes, not the symptoms. Concerted global efforts to curb the emissions that are driving climate change and the elimination of dams along inland waterways are both urgently needed lest we want to keep spending millions of dollars on remediation projects that just have to be repeated over and over again in what is essentially a losing battle.

Contacts: ASBPA,; Ken Rubin,

EarthTalk® is written and edited by Roddy Scheer and Doug Moss and is a registered trademark of E - The Environmental Magazine ( Send questions to: Subscribe: Free Trial Issue:


Hidden River

A new green space along Philly's Schuylkill River brings calm to the stress of city life.

On a bike commute across Philadelphia the other day I came across a wonderful new park along the Schuylkill River, which is said to be part of an extensive placemaking project named Schuylkill Banks. The river was named the Schuylkill by Dutch explorer Arendt Crossen, the name translates to Hidden River in Crossen’s native language. Although it remains unclear why he chose this name, it has clearly remained a hidden river for many Philadelphians, including me.

The new park, located in the Greys Ferry area, is part of a city initiative to make green spaces along Philly's waterways, which the website describes as "part of the Schuylkill River Trail, a 23-mile link from Philadelphia to Valley Forge National Historical Park, and part of the nationally designated Schuylkill River National Heritage Area. Plans call for a continuous trail following the river, which starts in the headwaters of Schuylkill County and winds 130 miles down to its confluence with the Delaware River, at the southern tip of the city of Philadelphia." More

The above article was originally posted in our sister blog, Designer In Exile.


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