Protection at the Water’s Edge

July 2, 2015

Shorefront Protection on Cape Cod
Located near the “elbow” of Cape Cod, the small town of Orleans, MA, is bordered on the east by the Atlantic Ocean and on the west by Cape Cod Bay. It is home to some 6,000 residents.

The property of one of those residents had suffered a substantial streambank collapse, and the owner called in local Coastal Engineering Co. to help. Roger Michniewicz, manager of the Marine Division of the company, describes the situation.

“It was a shorefront site on Cape Cod. It had a previous coconut-fiber roll shorefront protection system put in about 18 years ago. It was covered over in sand and earth material, and planted over. The previous system lasted many, many years—well beyond its expected timeline. But by now, it was essentially completely disintegrated, other than the synthetic netting.

The owner was interested in a similar system. “The product has been improved,” notes Michniewicz. “Those coconut-fiber rolls are packed really, really tightly. I believe they are now 20-inch-diameter rolls. The previous installation used 12-inch-diameter fiber rolls. They were stacked four or five rolls high, for a length of 100 feet or so, on a sloped angle of about 40 to 45 degrees. This was against the eroding toe of a vegetated embankment that had trees and other vegetation above.

“Due to storms, there was some scarping in that area. The system worked well for all those years, which is highly unusual. However, it is a somewhat benign location as far as susceptibility to erosion by storms.”

Perhaps due to the surprising success of the previous installation, Michniewicz decided to use a similar solution. The construction management firm NETCO, based in Lexington, MA, was selected to be the installation contractor for the job.

“This system was put in to pretty much match what was done previously, although we used larger coconut fiber logs,” says Michniewicz. “The previous system was actually held in place by a system of rope cable that went around the fiber rolls, and then they were attached to small helical piles. In those early days, these were actually agricultural items, and they have a 5-inch-diameter corkscrew blade. The shaft was of about a half-inch diameter with a loop at the end to attach a cable or a rope. These were then twisted into the ground, and they were probably around 40 inches long.

“For example, these might be used if you were planting a sapling tree, and you wanted to hold it down to an anchor from three sides. So this was really an agricultural landscaping product that was jerry-rigged to a system holding these fiber rolls against the embankment. There were a number of them.

“Nowadays, these helical piles are much more robust, more heavy duty. What we found on this particular application, however, was that after we cleared away debris, those helical anchors were still intact and still usable. They didn’t exhibit much corrosion, even being in this marine environment. So we were able to utilize those in the installation of the new fiber rolls. We tied the new fiber roll system to the embankment using the previously installed helical tiebacks.

“Our installation, like the previous installation, was covered with a foot or so of sandy soil, and this was planted with Native American beachgrass. This was put in to develop a root system that would help tie everything together and hold the soil together. For this particular location, it worked very well.”

Today, the coir logs can’t even be seen. Occasional maintenance, however, is required.

“Storms may, from time to time, remove surface materials,” explains Michniewicz. “Usually, the document from the conservation commission, called the order of conditions, mandates that you maintain them and keep them covered. Typically, the owner will want to do this, because the coconut-fiber rolls are organic and biodegradable, and susceptible to ultraviolet degradation when exposed to the atmosphere. So you want to keep these fiber logs covered, to extend their lifetime.”

Michniewicz notes that the type of work that was done on this project is very heavily regulated. Getting the necessary approvals can be a difficult task.

“There can be a little confusion among the public regarding why we are even putting in something biodegradable. It comes down to what’s allowed by environmental regulations, which are very comprehensive, especially in Massachusetts. It determines what is protectable and what is not protectable.”

Not only are projects such as this one regulated under the Massachusetts Wetland Protection Act, he says, but “virtually all towns in Massachusetts have enacted their own wetland protection bylaws. When we do a filing, we have to file for permission under two entities. The local conservation commissions have a tremendous amount of control. For this particular installation, only a soft solution for erosion control was allowed, not a rock revetment or a vinyl or wood bulkhead.

“Also, the permittability of these systems varies considerably from town to town, even in a region like Cape Cod. It’s based upon the feelings and philosophies of the conservation commission members who happen to be sitting on the commission at the time.”

So even though some of these “soft” solutions may not hold up as well under all conditions, property owners may well be limited in their options.

Michniewicz points out another important issue that property owners must be aware of when implementing erosion and sediment control measures. “The state Wetland Protection Act and other regulations recognize that erosion of certain areas is a natural process that provides sediment to other areas, such as coastal beaches and dunes. We’re armoring for protection of property and structures, although in doing so, we’re inhibiting the free, natural movement of material.

“When we work on these projects, we have to be cognizant of this loss of material. So most commissions require that if you armor, you also have to provide a sediment source on a regular basis. You may have to come back perhaps once a year to provide an estimate of what would have been the volume of sediment that would have left the site annually, by way of erosion, to continue on down the beach. Then you have to place an equivalent amount of a compatible-grain-size sand on the site, on an annual basis, to make up for the loss of sediment that otherwise would have reached the area.

“So we’re always playing a game of armoring—preventing erosion for one purpose—but the owners, through these conservation commissions, are required to provide augmentation, knowing that it will be washed away on a regular basis.”

So simply protecting one’s property from erosion can create new obligations for years to come.

“That’s part of the approval process. An issue also becomes, post-construction, how do you get the material there, year after year? An arrangement may need to be made for provisional access to a particular site. It can be cumbersome. But it is a requirement.”

Michniewicz was pleased with the work NETCO, the installation contractor, did with this property.

“On this project, we went through permitting, produced the plans, and then assisted the homeowner to put the project out to bid with a half dozen potential contractors. In this particular case, NETCO was the successful bidder.

“They are a very successful company, because they work on an awful lot of projects throughout New England.”

Rescuing a Pond in Indy
A homeowner in Indianapolis has a small pond, about an acre in size, on his property, used for swimming and fishing. But he was having a number of issues with the pond.

The outfall had been severely damaged, erosion was occurring on the banks, and the water was exhibiting high turbidity.

The pond had been treated a couple times for algae, but not very successfully. The property owner called in J. Eric Spangler of Hoosier Aquatic Management to try to resolve the various problems.

“We did two things,” says Spangler. “We used the vegetated Living Log, from Living Log Aquatic Services, around the shoreline, and we got that stabilized.

“Then on the outfall, we used vegetated soil tubes. These are like big sand bags made out of nonwoven geotextiles. We created a weir structure for the outfall, so we got the water running where it needed to be. The water had eroded the banks and then it blew out the outfall, so then it got too low, causing even more erosion.

“In addition, we also did some bacterial enzyme treatments to get rid of the organic solids and general muck that were at the bottom. This, in conjunction with the Living Logs, really helped out with the water quality and it increased the dissolved oxygen.”

Spangler estimates that turbidity was reduced by 60–70%.

“Previously, you could see a foot down or so. Now you can see to the bottom, and it’s about 10 feet deep.”

He explains that although the structural work is completed, he is still treating with the bacterial enzyme a couple of times a year.

“Because it’s in a wooded area, there’s a lot of leaf litter in the fall, and this breaks down. So it’s an ongoing treatment from the bacterial enzyme standpoint.”

Spangler estimates that he used about 250 feet of the Living Logs around the pond shoreline, and roughly another 30 feet for the weir structure. The Living Logs were built with a variety of wetland species, including marsh milkweed, different sedges, and some iris plants.

To build the weir, he had to dewater a bit, dropping the water level perhaps 18 inches below where it had been. But after the weir was in place, the water level rose about 3 feet, thereby going above its prior level.

Other than the occasional bacterial enzyme treatment, not a great deal of maintenance is required. “We do go through to see if any invasive species are trying to get established on the shoreline,” he says. “So far, this hasn’t been a major issue. We go out about four times a year, so we’ve got a pretty good handle on it.”

Fortunately for the property owner, no special approvals were required. Spangler notes that most projects under 300 linear feet are exempt from the permitting process in Indiana, and this project fell just under that threshold.

He adds that the work was scheduled outside the rainy season to avoid the need for bypass pumping. The project was completed within a couple of days. With the material Spangler used, access wasn’t a problem, either.

“That’s the nice thing about the logs and the soil tubes. We can get them into areas with very difficult access. It’s often a ‘throw it over your shoulder’ thing. We don’t really use any heavy equipment.”

As for the property owner, he is “ecstatic” according to Spangler. After less than satisfactory results from the earlier algae treatment, he is now thrilled with the appearance of his private pond.

What Goes On at the Fertilizer Plant Stays at the Fertilizer Plant
About 15 minutes south of Burlington, IA, in the southeast corner of the state, a large 300-acre fertilizer plant rises from what had previously been farmland.

“This is one of the largest active job sites in the country,” says Nate Parks, Soil-Tek project manager for eastern Iowa. “We were in charge of doing the erosion control, particularly around the perimeter. They have roads throughout this job site. They’ll install a road to get cranes somewhere, then they’ll remove it. So we’ll come in and put in silt fence or filter tubes filled with wood mulch.

“We’ve got quite a bit on our contract—about 3,000 feet of our 12-inch Soil-Tek filter tubes. This last go-around, they had us do a bunch of checks down a ditchway, about 100 feet apart. They had a grass waterway that came through the whole site. It was protected wetlands.

“At the very end of this waterway, where it met the road, they had put rock down. It’s triple-stacked now with 12-inch filter tube, to act as a sediment barrier at the very limit of the project.”

Originally, he says, crews placed double-tubes, but the flow of water was great enough that it began to overtop the tubes. “So we put a third level on. We used steel posts on either side to pinch all the layers in, so no sediment can get through.”

He adds, “This is one of the only jobs where I’ve had to triple-stack 12-inch fiber tubes. It’s one of the first things you see when you come to this job site—it’s at the access point for all contractors, so the first thing you see when you pull up are the triple-stacked tubes on the wetland.”

Although most of the sediment control at the site concerns the perimeter of the area, some internal measures have also been necessary.

“Some of those roads they make are just for a short period of time. They’ll put a culvert in, put rock down, have a crane drive over it, and two weeks later the road is torn out. We’re not as involved with those, but for some of the main ditches that are more permanent, we’ll put filter tube check dams through them to slow down the water flow. We’ll put a U-shaped structure in the ditch to maintain the soil in the center of the ditch and keep it from escaping. We stake those in with inch-wide wood stakes to keep the filter tubes in place.”

According to Parks, the area doesn’t drain particularly well, so a lot of water ends up in ditches and other low-lying areas.

“This water goes through all the culverts, and our mission is to have all the water that leaves the site be crystal clear, not full of sediment. We all realize that the water has to go somewhere. We’re just trying to make it completely clear as it goes over our last barrier, our last filter sock. It’s working pretty well.”

He notes that sediment has been of particular concern on the site.

“The EPA is watching the entire project very carefully. They actually came last summer and caught one of the contractors (it wasn’t us!) who was pumping water off from the site, dumping dirty water into a ditch outside of the job site. So the EPA audited the project and did an inspection, going through the whole job site, checking all of our controls.

“The fertilizer company having the site built began to get worried—maybe got wind of a violation or big fine coming—so we went down and fixed everything for them. That’s when the double-stack and, later, triple-stack, of fiber tubes went in. That was actually an idea from the EPA.

“We have 12-inch tubes in the ground to stop anything inside the site from coming out to the exterior ditch. There are still a couple sections that are double-stacked. All throughout the main road, the EPA is watching over things very closely, so everyone’s trying to stay on top of it.”

In addition, because the site is on a protected wetland, there are other issues to contend with.

“When we first came in and it was just farmland, we installed all of the silt fence and filter tubes to basically protect the wetlands,” says Parks. “We were told that if we came across any bird nests or similar things, we need to report it and leave it alone.

“In addition, we had to put up special signs and install orange snow fence. This is a 4-foot-tall orange fence that is highly visible. We installed this around the wetlands. It gave a clear warning to the dirt movers and the bulldozer operators that if you’re getting close to this orange fence, you’re getting a little too close.

“On most job sites with wetlands, something similar is usually needed. It depends on each city and how strongly they enforce this. Sometimes, the site may be so tight and congested that they can’t realistically put up this fence. But if it’s in the specs, then it has to be there.”

Depending on the level of retained sediment, occasional simple maintenance may be required.

“In certain areas, where there is dirt actually hitting them, we may go in with a shovel and just clean out the area in front of the tubes, or we may lift the tube up, clean in front of it, and re-install it so that it’s not at capacity.

“In other areas where it is all muck and muddy, they’ll dig it out with a backhoe or an excavator where all the sediment has built up. It depends on the job site and the site conditions.”

Perhaps because the Soil-Tek filter tubes are made of durable material, other workers tend to drive over them. They’re not intended for such continued use, though, and may rip over time, spilling the mulch inside.

Should this occur, Parks’ team comes in and reinstalls the damaged section. He notes that he has a company stormwater inspector visiting the site weekly who takes care of these minor repairs.

Credit: NEDIA
Before work began on the Ivanhoe golf club

Restoring #7 at Ivanhoe
The beautiful Ivanhoe golf club on the north side of Chicago traces its beginnings to 1949. Having recently undergone a multimillion-dollar renovation, it regularly earns the distinction of being recognized as one of the top championship courses in Illinois.

Three distinct nine-hole courses occupy the grounds, with the Forest Nine marking the highest topographic position in Lake County. It was hole #7 on this Forest course that was recently part of a lake bank restoration process.

“It was a pond that had eroded over time,” explains Ryan Ochs, assistant superintendent at the Ivanhoe Club.

In deciding how to stem this problem, Ochs ended up using 120 of the 10-foot long KoirLogs from Nedia Enterprises, a Virginia-based company that has been supplying biodegradable erosion control products nationwide for almost two decades.

The KoirLogs are natural coconut-fiber logs made from double-cleaned, unsorted coconut fiber encased in high-tensile-strength coir twine netting. The logs can be prevegetated with seedlings or plant cuttings, and this was done with the Ivanhoe Club project.

Credit: NEDIA
The finished site

The inherent nature of the coir fibers to absorb and retain moisture provides an ideal medium for vegetative establishment and growth.

“We started in the early spring of 2014 and finished about a month later,” says Ochs. “We used 1,200 feet of these logs.

“We staked it out first, in the water near the shoreline, with wooden stakes, and we put those stakes all the way around the pond about every 2 feet, so we knew what line we were going on. After we were done with the stakes, we added 1- to 3-inch limestone rock all the way along the base of the lake, about a foot past where we put the stakes.

“So from the eroded lake bank to a foot past the stakes, we had our limestone rock at the base. We put this from the edge of the lake bank to a foot past our desired location.”

The positioning of the stakes relative to the water varied along their course.

“It depended on how far we wanted to take out the lake bank,” says Ochs. “Some areas were a little bit farther than others. Along the green, we took it out a little bit farther, so it gave a little more leniency to the golfers if they mis-hit their shot on the green and it hit on the lefthand side. It provided a little bit of a ‘give’ there.

“After everything was staked and the rocks were positioned, we put the coir logs in, and we abutted those against the stakes, with the back of the logs right up against the stakes, and then we zip-tied the logs together. Wherever the logs bumped up against each other, we put another stake right there for additional support.”

Ochs notes that the rocks were still below the water’s surface, so the bottom of some of the logs sat in the water itself.

“After we put down the logs,” he continues, “we used a clay fill to fill in the area from the eroded lake bank to the logs. We used a packing plate to pack all that clay in there, right against the logs.

“Once we were finished with that, we draped sod over the logs; the sod grows into the logs. When you’re finished, it looks all natural, as if you hadn’t done anything to the lake. It’s like it had been there forever. That’s how it’s supposed to look.”

He notes that the club chose Nedia KoirLogs because they offered a 100% green solution as well as the best value for the money. “We weren’t going to put a sea wall in, because that would have been too expensive. We wanted a natural look, and this was the best method, in our eyes, to accomplish that.”

Ochs says he didn’t face any particularly difficult challenges with this project, but he notes that experience with this type of bank restoration has proven very helpful.

“One of the things that we learned from the past was to use a compacting plate to really pack things in. If you don’t, you’re going to have some indentations over the winter.

“Another thing we learned was to add a stake where the logs come up against each other for more support, so things don’t move when we’re dumping the clay between the lake bank and the coir logs.

“It went really smoothly. It’s held up over this Chicago winter very well.”

To date, no maintenance has been required. In fact, there has been a savings because in the past, the club wasn’t able to use its riding lawnmowers between the green and the lake. Now they are able to do so, resulting in a cost savings for the club.

As for the club members, the golfers absolutely love the upgrade, says Ochs. “In fact, there are a number of other golf courses in the Chicago area using the same kind of logs, with the same process that we used.” 
About the Author

Steve Goldberg

Steve Goldberg writes on issues related to erosion control and the environment.