Scientists are not so bullish on nourishment

By on April 5, 2011

A 2009 nor'easter did serious damage in South Nags Head.

Coastal geologist Stan Riggs lived in South Nags Head in the early 1970s, when the beach was wide and houses were few.

“It was wild empty land, and lots of big dunes,” Riggs said in a recent interview. “So that shoreline has moved almost 1,000 feet since then.”

Over the course of his 46-year career, while conducting studies of the Outer Banks, Riggs has been witness to the rapid oceanfront development in Nags Head, the shoreline’s intractable erosion, its seasonal walloping by storms, its sad sandbag-littered diminishment.

A geology professor at East Carolina University, Riggs understands why the tourism-dependent town has aggressively pursued a beach widening project. He is sympathetic to property owners who desperately want to save their homes.

He just doesn’t believe Nags Head’s proposed $34 million beach nourishment project has much, if any, chance of being successful.

Stan Riggs. (ECU photo)

“If you go through a five-year period of no storms — it might last that long. But on the other hand, it’s not unusual to have two, three, five nor’easters,” he said.

“And if we do, it’ll be gone. If they get it on this spring, it could be gone this summer.”

Nags Head officials believe, however, that the sand will last much longer and are moving ahead with financing the project. The town has chosen Great Lakes Dredge and Dock Co. to do the work, which could start by mid-June. But that will depend on what happens to a lawsuit challenging the town’s process for obtaining easements.

No stranger to Outer Banks residents, Riggs has given numerous public presentations about coastal processes, sea level rise, and yes, beach nourishment.

Besides sheer luck in storm-dodging, success or failure with nourishment comes down to the underlying geology, the land under the seawater. Some of it does not lend itself to a stable beach that would respond to sand replenishment, he said. Kitty Hawk, for instance, is sitting on an inner stream divide, a high area between two valleys. Mirlo Beach is located on angled rock.

South Nags Head is often cited as a reason for pushing forward with beach nourishment. It is also viewed as a reason why pumping sand onto the beach could be a bad bet.

And South Nags Head, Riggs said, is part of an area that has always been dominated by inlets and old stream valleys. That means the town, essentially, is planning to put sand on a beach that geologically wants to move.

“I suggest those people never go to Las Vegas — they don’t understand risk at all,” he said.

At a March 16 panel discussion sponsored by the League of Women Voters of Dare County, Dorothea Ames, Riggs’ partner in the ECU geology department, emphasized that statistics may determine an “average” erosion rate, but in reality, an eroding beach may seem stable or even accrete part of the year.

Then one persistent nor’easter, or a series of northeast slams, or one big tropical storm during a spring tide can wipe out a shoreline and the dunes in a matter of hours or days. A powerful nor’easter in November 2009, for example, damaged or destroyed dozens of houses in South Nags Head and consumed much of the shoreline and dune.

Ames was giving her geologist’s counter to the town’s pitch that says its proposed beach nourishment would last 10 years based on erosion history.

“There’s no such thing as an average erosion rate,” she told the small audience. “Most of these projects do not last very long in northeastern North Carolina because there’s high energy.”

South Nags Head’s erosion rate, according to the state, averages 4 to 6 feet per year over 50 years, or a loss of about 275,000 cubic yards since 1994. Sea level rise, Ames said, is only going to worsen the rate.

Great Lakes Dredge and Dock Co. has completed several beach nourishment projects, including this one in Brevard County, Fla. (GLD&D photo)

But another veteran North Carolina coastal scientist was less pessimistic. In a series of slides, Spencer Rogers, an erosion specialist and coastal engineer with North Carolina Sea Grant, illustrated successful long-term, although larger, nourishment projects in locations like Carolina and Wrightsville beaches.

At the same time, he cautioned that beach fill “is a treatment, not a cure” that must be maintained, is not cost effective in high erosion areas and must be a community-scale project. He also said that smaller projects — like the one proposed in Nags Head — could be effective in addressing long-term erosion, but are “not particularly” effective in storm events.

Despite those factors, Rogers said that inaction could be the most expensive choice. At the very least, even if some or all of the sand is lost, nourishment would buy time for Nags Head.

“The controversy over beach nourishment, in my experience, has less to do with beach nourishment than with who’s paying the bills,” he said, responding to an audience question about cost-benefit analysis. “If the issue is who pays, then the other issue is who benefits?”

Some contend that the project, especially one that is not full-scale, will not survive 10 years without having sand replenishment every few years. In addition, federal funds will not be available to rebuild a storm-damaged project without a maintenance component built in from the onset.

In the unfunded 14.1-mile federal nourishment project authorized in 2000 for Kitty Hawk, Kill Devil Hills and Nags Head, the Army Corps of Engineers planned to use about 8 million cubic yards of sand on the 10-mile Nags Head section, with renourishment planned in intervals of about three years. Nags Head plans to use a total of 4.6 million cubic yards in its proposed project.

Surf can come precariously close to the Comfort Inn.

The 50-year total cost of the federal project was estimated at $72 million for construction, with about $18.2 million annually for maintenance. Only $500,000 was appropriated for pre-construction.

Charles “Pete” Peterson, marine science professor at UNC-Chapel Hill, said in a 2006 interview that nourishment projects on average last about five years, with huge variance. One project, he recalled, still had pipeline on it when a storm wiped all the pumped sand away.

A beach must be engineered to certain specifications and maintained regularly to be eligible for permanent repair under Federal Emergency Management Agency rules. The repair must be needed to protect improved property from immediate threat.

But Rogers sidestepped the significance of scale and degree, saying it is too difficult to accurately estimate how a beach like Nags Head will respond.

“The way you really find the performance is to build it and see how it performs,” Rogers said after the presentation.

“One of the nice things about beach nourishment is it doesn’t commit you forever.”

Beach nourishment works great in some places: It’s been very successful in Miami Beach, where the flat nearshore and ocean waves are comparable to those in the Outer Banks’ sounds. Longtime nourishment of about three miles of beach in nearby Sandbridge, Va., has been credited with expanding the shoreline and jacking up property values.

Other effective beach-widening projects in North Carolina were built on less-energetic southeast-facing beaches, and were usually fully-engineered large-scale projects with regular maintenance schedules.

But much of the Outer Banks, including South Nags Head, Riggs said, has steep northeast-facing high-energy beaches. Sediment transport from north to south is some of the highest on the coast. Mirlo Beach, known for having the biggest waves on the East Coast, has a rock offshore that runs north-northeast at an angle that causes storm-driven waves to focus energy toward the beach.

“Nobody goes to Miami Beach to surf,” Riggs said. “I think people need to keep perspective where they are.”

Riggs also has been a member of numerous state science and coastal policy panels. He and Ames co-authored, “Drowning the North Carolina Coast: Sea Level Rise and Estuarine Dynamics” and are two of four authors of “ The Battle for North Carolina’s Coast, ” scheduled for release in September.

Considering that South Nags Head is in the same neighborhood as Oregon Inlet, a stubbornly unruly waterway, Riggs said that beach nourishment there would require a long-term, costly commitment that he compared to having children.

Instead, he believes Nags Head should do what Kitty Hawk has done: start getting the houses off the beach and keep them off the beach. Keep infrastructure on the west side, far from the reach of damaging surf.

“We don’t need to abandon the barrier islands,” he said. “We just have to get smart about living on them.”

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Comments

ekim

April 14, 2011 7:58 am

TC how about the new dunes in front of the old NH head dunes?

Pimpernel

April 12, 2011 8:02 am

It’s interesting that since the beginning of this quest the voters (taxpayers) have consistently said “no” to beach nourishment, more often than not, joined by scientists who have no dogs in the fight. But the tax-eaters, who can mostly be found in the phone book under ‘Real Estate,’ will never be dissuaded. And what is the result?

Concerned

April 11, 2011 7:04 am

One major storm and you can kiss all the taxpayer dollars dumped onto the beach and into the contractors pockets goodbye, then what raise the sand tax even more and do it again?

Chris

April 10, 2011 9:59 am

Should be required viewing for those in the debate:

http://coastalcare.org/2010/03/north-carolina-the-beaches-are-moving/

Sounds like what Dr. Pilkey is preaching…

TC

April 10, 2011 9:06 am

Is anyone aware of the fact that sand dunes (in the present form) did not even exist along our coast until they were put there by man ?
If you block the natural occurring action of the ocean it has no way of releasing it’s energy so it takes what’s in it’s way, that being the beach.

Houses and dunes are like a bulkhead that the waves slam against and it in effect digs out what’s in front of it. But everyone loves an ocean front home so that won’t change until they all fall into the sea.

At least Nags head came come and dig their sand out of Oregon inlet next year and put it back on the beach because that’s where it will end up.
How many jobs will beach nourishment create versus opening the inlet so folks can continue to work ?
It’s all politics.

ekim

April 9, 2011 10:32 am

MOST of us didnt need a scientist to tell us IT AINT GONA WORK!!!

outerbanker

April 8, 2011 7:02 am

Typical politics, forgot the facts, do what they want. Any moron knows that the sand will not stay, when has it ever. Can we get that 8% sales tax any higher, please. And tax the tourists alot so they will go elsewhere. Great plan, whose running nags head, Obama? Nags Head officials are idiots and should be kicked out of office.

Kinnakeeter

April 7, 2011 1:59 pm

Has anyone eastmated what impact the dredging of offshore sand in Nags Head will have on Hatteras Island in general and Pea Island in particular?

charlie

April 6, 2011 5:15 pm

Mary has the obviously simple answer. Dig it up and move it back…

Ray M.

April 6, 2011 12:10 pm

If our local newspapapers and internet editions could make money on subscriptions alone, and not have to sell advertising, you would see a big difference in the way news is reported on the Outer Banks. Sad, but true.

David

April 6, 2011 11:09 am

GW thanks for posting info re. Holberg Tech method. Very interesting – hope it’s been fully investigated for use on the OBX and if not, it positively should be.

chuck

April 6, 2011 10:39 am

here in the northeast (NJ) beach fill is seen as the be all and end all of shoreline repair. generally, beach nourishment consists of pouring lots of money on the shoreline about every other year and they watching it move away till the shoreline is back where you started and then pouring more money in the form of sand on the shoreline again. it looks great for one summer and then gets worse and worse for the next few years till you back where you started. there are other solutions but they are not ‘acceptable’ by the COE or most mainstream advisiors, therefore they will never get a trial. sea level is rising and sand will move southward and offshore…these are givens……..it’s your money, NO wait, IT’s my money too!!!!!

Tide master

April 6, 2011 8:04 am

Russ, you are and have been a strong supporter of nourishment, that is no secret and it’s OK.

But you are also the voice of this site. All of your commentaries lean your way, and that’s fine, between that and where your ad money comes from, we expect it. And we appreciate the forum very much.

The issues I believe the majority would like discussed from a neutral standpoint are:

How is it that only one engineer, Mr. Kana, who is raking in money fron this project, says that it is a good idea, an no one prints other opinions? (until now, again, kudos).

This “catchphrase” that the beach is doomed, print the real numbers please. We add far more houses each season than we could ever lose from erosion. Our occupancy climbs steadily. We could lose half of South Nags Head and never even feel the dent. Question Mr. Oakes on those outlandish claims.

Someone needs to speak for the majority. Voters here are not behind this project. We understand the issue. The vocal propoenents tend to be vacant homeowners or those with serious oceanfront real estate businesses. The locals feel as if their opinion does not count as the mayor and Mr. White and Mr. Judge continue to run end-around after end-around to try to get this done. (You did a good job on that reporting that they should take a breather, but with elections looming for Oakes, good luck).

Again, in each of the stories above, you have a problem with the PATH to nourishment, not the intelligence of actually dumping sand on our beach (again). Nothing stays put out there. “Compatible sand?” What? There is no scientific proof or evidence that is even a real thing.

Anyway, please keep up the better work. Kozak’s article was solid, but it should have been run years ago, in the beginning of the process.

ekim

April 6, 2011 7:53 am

This isn’t about beach norihsment this about N.H. taxing everybody for their pockets, And when B. N. doesnt work do you think they’ll drop the tax! NO! Just like the yanks do with bridge tolls they put the toll up to pay for the bridge, not one has ever taken down!

Mary

April 5, 2011 11:40 pm

Pump the sand out of Oregon Inlet and put it in South Nags Head. Problem solved in both areas.

Russ Lay

April 5, 2011 8:31 pm

Tide master: You should read more often:

http://outerbanksvoice.com/2010/01/24/take-the-warranty/
http://outerbanksvoice.com/2010/01/22/a-visual-commentary/
http://outerbanksvoice.com/2011/02/21/beach-plans-seem-to-come-and-go-like-the-tide/

These are just a few. We have also invited beach nourishment opponents to write op-eds and so far, they have all declined.

Elihu

April 5, 2011 7:17 pm

Does anyone know why an artificial reef isn’t even being studied as a possible alternative? I know the current laws prohibit beach hardening (except when the govt decides it is necessary), but if both beach nourishment in Nags Head and additional dredging at Oregon Inlet are being simultaneously considered, then why not also consider adding an offshore buffer zone to possibly protect both investments?

Truck

April 5, 2011 4:43 pm

The obvious issue is overdevelopment, but we’ve know that for years. Few people criticized the development, and a few in the area made A LOT of money on it. Now that the area is so dependent on tourism, the local economy is hooked on the tourism drug and there appears to be little option, other than nourishment, to support that industry i.e. no beach, no economy. One could take the “natural” approach and let things erode, yet if that’s done, why spend money continuing to dredge Oregon Inlet ? The only benefits only a few and costs a ton.

GW

April 5, 2011 3:34 pm

There’s so many sides to this argument that I wonder if the public is even aware of all the options and implications. Everyone knows that nourishment is expensive and temporary. That’s not even up for debate. HOW temporary is the biggest question. Maybe there’s other options that aren’t being actively considered.

There’s no doubt that the OBX is a special place in many ways and it’s geologic make-up is no less special. We all know that waves are created by wind and the OBX is one of the windiest places on the east coast of the U.S. (that’s why the Wright Bros came here – remember?)

9 years ago, John Harris of KHK and I traveled to Grandfather Mtn. to meet with it’s owner – Hugh Morton. Mr Morton was one of the best known promoters of the state of NC (you can google him to see his accomplishments) and Mr. Morton introduced John and I to the work of Mr. Holmberg (of Holmberg Technologies). John and I took the info back to the OBX and it was batted around for a while until a single man who had a lot of clout – Dr. Orrin Pilkey – shot it down.

There’s a tremendous amount of politics surrounding Mr. Pilkey and I wonder why the Holmberg method has not even been considered for a test area. It may not work, OR it could be a semi-permanent solution. You can read about the Pilkey controversy here: http://www.erosion.com/armycorp.asp

You can also browse the Homberg method on their website: http://www.erosion.com/index.asp

It seems that the “Outer Banks Voice” not only has the power of the press, but also (from what I’ve read) has the balls to challenge authority. Possibly it would be worthwhile to investigate the Holmberg system and ask publicly why it’s not being considered.

Just a thought.

glennk1949

April 5, 2011 3:13 pm

“We don’t need to abandon the barrier islands,” he said. “We just have to get smart about living on them.” Duh! But, that’s just the pt. the sand millionaires like Weeks marine and Great Bay Dredging don’t want us to be smart, they want us to be stupid and scared. Putting sand on the beaches @ the Outer Banks is just plain stupid! Why not put sand on the North Shore of Hawaii then, both places have the same kind of wave energy environment. Of course it would be easier to just move the homes back and prohibit building in those areas, but that might offend a few rich folks and we can’t have that can we?

jonh

April 5, 2011 3:09 pm

“Nags Head officials believe, however, that the sand will last much longer and are moving ahead with financing the project.” Typical politician mindset, they know more than the experts. Where did the Nags Head Town Council & Mayor receive their coastal geology degrees from?

Tide master

April 5, 2011 2:27 pm

I never thought I’d see the day that this site ran a story asking whether or not the nourishment idea is a good one to begin with. History says no, but it goes largely ignored.

Instead, your editorial has always been, “Nourishment is so super-GREAT!!!! but the plan concerns me because ______ ”

Thank you. In my mind, you just took a huge step toward balanced reporting. By the comments I read, this is the key question a majority of your readers wants to discuss.

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