Taking a hint from Mother 



You shouldn't try to fool mother nature, but 

 sometimes it pays to steal from her. 



Sea Grant researchers Steve Broome, Ernie 

 Seneca and Vince Bellis are taking nature's ideas 

 for protecting the estuarine shores and experi- 

 menting with planting grasses and trees. They 

 figured if it worked naturally, it would work with 

 a little help from man, too. And natural protection 

 would be less expensive than bulkheading, they 

 reasoned. 



"We've 'proved' it works, at least we've proved 

 it works in some places," said NCSU soil scientist 

 Broome. "And we say it usually costs less than $1 

 a linear foot." Broome and Seneca have been plant- 

 ing marsh grass on eroding estuarine shores for 

 the past two years. They have 11 test sites, some 

 of which have been successful and some of which 

 haven't. 



Leroy Voris, is a Pine Knoll Shores resident who 

 lives in back of an experimental Spartina alterni- 

 flora and Spartina patens patch facing Bogue 

 Sound. The plot is working and Voris is extremely 

 satisfied with the venture. 



"It's been very gratifying. We were having some 

 erosion, but we didn't want to bulkhead. We prefer 

 the natural shoreline, as long as it doesn't wash 

 away. The grass seems to be doing fine and we 

 enjoy the big white herons that come in. There 

 have been a lot more birds since the grass was 

 planted." 



Seneca and Broome also planted grasses near 

 Uncle Henry's Oyster Bar at Masonboro Sound. 

 The Army Corps of Engineers was having erosion 

 problems in the intercoastal waterway there and 

 wanted to try grass planting. So far, it seems to 

 work. 



Doubly good 



"By using a natural substance such as Spartina 

 you accomplish two things at once," said David 

 Frankensteen, a fishery biologist with the Corps. 

 "Spartina is one of the most productive systems in 

 the world in terms of energy and biomass and it 

 provides detritus for all the little estuarine organ- 

 isms which eventually go into the commercial fish 

 species. So we're contributing to the detrital food 

 chain as well as preventing erosion." 



Seneca and Broome intend this year to find out 

 what exact conditions are needed for Spartina 

 plantings to successfully slow erosion. 



Meanwhile, ECU biologist Vince Bellis is ex- 

 perimenting with using cypress and tupelo trees as 

 natural erosion barriers. He has planted trees in 

 the laboratory, in the swamps and on the beach. He 

 has also planted on the beach behind inexpensive 

 bulkheads to give the trees time to flourish. The 

 lab plantings are booming, the swamp trees have 

 all died and success varied on the beach. 



Research is continuing. 



A typical bulkhead 



Bulkhead booboos 



Bad bulkheads are easy to spot. 



The purpose of a bulkhead is to hold soil to the 

 shore. When bulkheads fail, it's obvious: the soil 

 slips into the water and the bulkhead eventually 

 follows. 



Bulkheads generally fail by water eroding be- 

 hind the wall either from the sides or the bottom. 

 If the bulkhead isn't protected or placed deeply 

 enough, water will dig under the wall and make it 

 fall. Water in the soil behind bulkheads must be 

 able to drain or the weight may push the bulkhead 

 over. If the draining water isn't filtered, the soil 

 will escape with the water leaving the bulkhead 

 without any back support. 



Bulkheads also fail when inadequate side walls 

 allow water to cut behind and steal the back sup- 

 porting soil. Inadequate tiebacks, or anchoring 

 systems, can also make a bulkhead give. And if the 

 wall material is too flimsy it can simply be broken 

 by the waves. 



So how do you do it right? 



"You can't give a canned design that will work 

 everywhere. A bulkhead is an engineering problem 

 that needs to have an engineered design that is site 

 specific," according to Jay Langfelder, engineer 

 and director of the NCSU Center for Marine and 

 Coastal Studies. 



Building a bulkhead is expensive — costs range 

 from $20 to $200 a linear foot— and many people 

 cannot afford to add an engineer's fee to a small 

 bulkheading project. Langfelder urges anyone 

 building a bulkhead to choose a contractor with 

 care. Walk around and see a few bulkheads he or 

 she has built before. 



(See "Bulkhead," page 6) 



Bulkhead lore . . . helpful clues and an address for more 



(Cont.from page 5) 



It's also useful to know a "few things to think 

 about" that can apply to any bulkhead project. The 

 first thing to consider is what forces will be work- 

 ing on the bulkhead. How deep should the pilings 

 be driven, what type and size pilings do you need? 

 Do you need to add wing walls to avoid side erosion 

 and how far back do they have to go? How strong 

 must the wall sheets be? Do you need tiebacks? 

 How many and how deeply should they be buried? 



What materials will work best? Make sure you 

 use corrosion-resistant hardware such as wrought 

 iron and galvanized steel and be sure all wood is 

 treated for use in the water. 



And, again, always make sure a filter medium 



Sad tales of erosion 



(Cont.from page 1) 



Stallings has tried planting exotic cypress and 

 grasses and building jetties and still the shoreline 

 recedes, dropping tons of soil into the sound. 



"Nobody knows what we could do," he said. "A 

 bulkhead would probably work but the cost would 

 be prohibitive. You're talking about more than the 

 farm would sell for." 



The stories could go on for pages. There's the 

 Lane farm in Perquimans County which has one 

 of the highest rates of estuarine erosion in the 

 state: it's lost 150 acres since 1950. Elsewhere, 

 there's the old house pump sitting in the middle 

 of the sound where a house once also sat. There's 

 Batts Island which in 1749 had 40 acres covered 

 with orchards and houses and is now reduced to a 

 shallow shoal and a lonely cypress snag. 



"Estuarine erosion is quite a problem," said 

 Thomas Harrell, of the Chowan County Soil Con- 

 servation Service office. "It's a problem and if 

 someone comes up with an answer for it, we'd like 

 to know about it." 



is behind the walls. Filter cloth keeps the soil be- 

 hind the bulkhead while allowing water to pass 

 through. Be sure there are no cracks in the wall. 

 Always be sure that heavy equipment is kept off 

 the wall. 



Understand what is happening to your shoreline 

 before you begin work. Many homeowners over- 

 build their bulkheads while others seriously under- 

 build. And remember that portions of the coast are 

 acting as units. Try to work with your neighbors 

 or local government to get comprehensive shore 

 erosion action. 



For more hints on bulkheading write for "Help 

 Yourself, a discussion of the critical erosion prob- 

 lems on the Great Lakes," available from the U.S. 

 Army Corps of Engineers, 536 South Clark Street, 

 Chicago, Illinois 60605. 



Closer to home, Sea Grant has appropriated 

 money for a coastal engineer to start work after 

 the first of the year. We'll let you know when he 

 or she is here and ready for questions. 



Come one, come all 



Three free workshops on an "Introduction to 

 Aerial Photoghaphic Interpretation and Remote 

 Sensing" will be held from 9 a.m. to 4:30 p.m. on: 



Dec. 7 and 8 — Marine Resources Center near 

 Manteo 



Dec. 16 and 17 — Marine Resources Center, Pine 



Knoll Shores 

 Dec. 21 and 22 — Marine Resources Center, Fort 



Fisher 



For more information call Simon Baker at 919- 

 737-2578. 



University of North Carolina 

 Sea Grant College Program 

 1235 Burlington Laboratories 

 North Carolina State University 

 Raleigh, N.C. 27607 



Mrs. Linda C. Smith 



Librarian 



Office of State Planning 

 116 West .lones St. 

 Raleigh, NC 27603 



