Increasing federal, state, and local regulations require that erosion control work must be done in a way that protects the environment. Using erosion control products made of natural materials can help achieve that goal, as the following projects show.
When Matt Kerkhof of Hoosier Aquatic Management first saw the 15-acre pond at Springmill Ponds subdivision in Carmel, IN, he knew that he could stop the erosion and make the site look and function much better.
“The shoreline of the pond had receded, up to 8 feet in some spots. The homeowners wanted to reclaim the shoreline, so we brought in soil,” Kerkhof says.
To stop the erosion, maintain the new shoreline, and beautify the perimeter of the pond, Kerkhof’s crew used Living Logs.
“It’s a way for us to introduce native plants while creating a protective factor for them to grow. It’s a soft revetment product,” Kerkhof explains.
The native plants sit within the Living Log, which is made of coir. The coir will train the plants to grow around it. As it biodegrades, the plants turn into a solid root mass.
“The Living Log instantly creates erosion control. Then in three to five years, the plants’ roots take over and stabilize the shoreline for the long term,” Kerkhof says.
The work on the pond took a few extra days because of having to add the soil. “We usually do 500 feet a day,” says Kerkhof. “The Living Log creates an instant toe, and then we can start to build it up.”
Kerkhof likes to put an erosion blanket under the Living Log. Within the logs, Kerkhof’s crew puts a native seed mix, but no fertilizer.
“We make sure there is good seed-to-soil contact. That’s a crucial step. We manually prepare the soil on the slope,” he says.
In selecting native plants, Kerkhof says, “We try to concentrate on plants that flower throughout the season. We include some that flower early, some at midseason, and some that flower late, aiming for a balance of color. Our whole concept is called “˜lakescaping,’ bringing a landscaping to the lake shore.”
The systems can be installed during most of the year. “We did installations during the last two major droughts. The native plants were slow to grow, but they have done well,” Kerkhof says.
The system creates a natural goose barrier. After the geese moved on, the swans moved in, along with some ducks. The bordering ring of plants also discourages children from getting into the pond.
“The plants grow up to about 3 feet in height, but because the ground slopes down to the pond, it’s visually appealing, not too tall,” Kerkhof says.
The border of plants outlines the pond, making it visible so that people are more likely to notice it. Kerkhof says that people have been known to drive into detention ponds in subdivisions, but the plants of the natural shoreline provide a deterrent against this happening.
Kerkhof’s project for the Wildcat Creek Watershed Alliance in Kokomo, IN, came about because of the need to protect an exposed power line. Erosion was creeping into a trail used by the public.
“We did installations in two separate areas,” Kerkhof says. “One wall was 14 feet in height by 60 feet in length, and the second wall was 4 to 5 feet in height and 90 to 100 feet in length. Both walls were of Living Logs stacked on top of each other with our staking system, to stabilize the shoreline.”
Native plant material was sandwiched between the coir logs. Kerkhof uses a mesic prairie mix suited for a transition zone between wetland and upland plants. Smooth leaf hydrangea is one of his favorite native plants to include because of its attractive flowers. As the plants grow, they cover the stakes supporting the bioengineered wall.”When the water comes up and recedes, it brings in more native seeds. Sediment washes in and fills voids in the coir. It’s great material for the plants to grow in,” says Kerkhof.
The Wildcat Creek project was done in the middle of winter. The cold temperatures and icy conditions made the work take a little longer, about three weeks. “We had to break the ice on the shoreline every morning,” Kerkhof recalls.
The first growing season after the installation was unusually rainy. “It went under water five times that season, but the system worked fine. Our system gets stronger as time goes on,” Kerkhof says.
Kerkhof offers a two-year warranty on plants and work his company does. “Ninety percent of the time, that’s just doing visual checks to see that the desired species are growing well and that there are no invasives.”
Kerkhof graduated from Indiana University with a degree in Fisheries and Wildlife Management. One of his professors in IU’s School of Public and Environmental Affairs recommended erosion control work to him. He’s been in business for 15 years.
US 95 in Idaho
Wildlands, based in Richland, WA, completed a major erosion control highway project in Idaho. The project required installation of about 40 miles (200,000 linear feet) of compost wattles-FilterSoxx from Filtrexx-along the sides of US 95 between Lewiston and Moscow.The work lasted for three years. It involved blowing compost into synthetic netting wattles, using a bark-blowing machine from Express Blower, which is part of Finn Corp.Eric McCrea, president of Wildlands, says the toughest aspect of the Idaho project was “the sheer quantity of it. The crew of three people was required to put out 2,500 linear feet per day.”Besides having to cover a lot of ground every day, the crew often didn’t have easy access to do the work. Slopes were steep, measuring 2.5:1.”Some slopes were as high as 250 feet. They required 13 rows of the wattles,” McCrea says.
As for working conditions, the weather “was everything from the dead heat of summer to extreme cold,” McCrea recalls. During the fall, “we would see 62-degree temperature swings in one day. It would be 30 degrees in the mornings and more than 90 degrees in the afternoons.”In the coldest weather, he says, “either material was freezing in the truck or the ground was freezing. Digging a 4-inch trench to put the wattle in was difficult with the frozen ground. The guys had to go slower.”The clay soil added to the difficulty of the work. “Clay is as hard when it’s frozen as it is when it’s wet,” McCrea says.
Pressure was on everyone to get the work finished because of a state requirement that erosion control work be finished by a certain date each fall. Experience has shown that having all disturbed areas covered with an erosion control product before winter sets in prevents having to rework a site.McCrea likes to use blown-in compost wattles instead of straw wattles because they are long. The longer length means fewer gaps between wattles, and hence better coverage.On the US 95 project, the crew didn’t have to use erosion control blankets or mats. They did install a compost berm in place of a silt fence.”
One of the bigger pros of using compost is that you’re adding organic material,” McCrea says. “In eastern Washington, we have a lot of arid areas. Where we’ve used compost on projects, the grass has grown considerably taller.”A family company, Wildlands has 40 employees. The company works over the entire western US and has done projects as far east as the Dakotas.
Lakeside Erosion
The roadway adjacent to the eastern side of Fremont Lake in Princeton, MN, had become a material of concern to local officials. Erosion there had to be prevented.”The wave action was pushing against the road and could impact the structural integrity of the road,” explains Greg Halverson of Brock White’s St. Cloud, MN, division. “We used Curlex Blocs to stabilize the toe of the shoreline and then transitioned out into a wood fiber blanket above.”Curlex Blocs have “worked extremely well on the streambank restoration there,” says Halverson. “The contractors like the different shapes of the Blocs and that it’s easy to install them.” In addition, he says, “It’s easier to get local material quickly, and it’s cheaper.”
Seed-free and resin-free, Curlex Blocs are made of renewable Great Lakes aspen. The curled fibers have soft barbs that interlock, as compared with straight, hollow straw fibers. That means superior resistance to wind and water flow velocity and strong terrain contact.
Installing the Curlex Blocs took three workers a week to finish in the late spring of 2013. The project was finished in the fall when willow stakes were harvested and then put in place through the middle of the blocks into the sandy soil. It took two days to plant the willows.This was one of the first projects done with Curlex Blocs, and Halverson and other Brock White employees were favorably impressed with them. “They’re really easy to maneuver on the site, but once they’re saturated, they’re here to stay,” he says. “They tend to saturate more quickly than coir fiber.”
The challenging part of the project was that the product was new to the contractors. “We had a manufacturer’s representative onsite on the first day to give the contractors technical advice,” Halverson says.
Brock White also advised contractors to use American Excelsior’s Curlex Blocs on an erosion control project on the Vermillion River in northeast Minnesota. This project was done in 2011.”
The installation has performed well, and it’s been tested,” Halverson says. “It handled ice fine, the freezing and thawing. Spring thaw is always a critical time, the most stressful for erosion control projects. It’s also when we get major rain events,” he adds.
A 450-Mile Pipeline
Coping with summer heat, winter cold, and lots of wind goes along with the yearlong erosion control project that Rodenberg Diversified of Carrollton, MO, is doing for Tallgrass Energy. Work on the project began in fall 2013 and is expected to be finished by fall 2014.
The project is in support of a 450-mile pipeline that runs from Plainville, KS, through Nebraska and Colorado to Guernsey, WY. Terrain varies, as suggested by the elevation of Plainville (about 2,450 feet) compared with that of Guernsey (about 4,500 feet). The pipeline easement varies from about 50 to 100 feet in width.”
This is a turnover project for Tallgrass, not a full-blown new line. Some sections are being lowered. The pipeline has been a transportation line for natural gas. It will become a way to ship crude oil,” says Bill Dooley, construction manager for Rodenberg Diversified.”We’re providing all of the erosion control work for the project. We’re using the Etubes for as many applications as possible,” Dooley says.
The Etubes, from Soil-tek in Grimes, IA, are mesh filter socks, either permanent (of polypropylene) or biodegradeable (cotton). They’re filled with wood mulch for sediment capture and water filtration. The biodegradeable Etubes will break down in two to three years.
Examples of biodegradeable Etube applications on the Tallgrass Energy project include creek crossings, waterway crossings, and around soil piles. Keep the topsoil in place not only keeps it out of waterways but also maintains it in convenient spots until it’s needed for the restoration phase of the project.Tallgrass Energy specified the use of Etubes. “The environmental specialist at Tallgrass Energy is very happy with this product,” Cooley says. “Our guys seem to be happy with using it, too.”
A family-owned business in operation since the 1950s, Rodenberg Diversified specializes in pipeline construction and maintenance. The company handles projects ranging from small urban sites to large cross-country, multistate areas.
Two in St. Louis
The details behind two projects in the St. Louis, MO, area illustrate the way staff members of distributor ASP Enterprises in Fenton, MO, like to recommend erosion control products to their customers.”We do not use straw wattles for bioengineered projects. We use them for sediment control or shorter-term work,” says ASP’s Don Thieman. “We like to use coir logs to protect toes of shorelines. They’re better for longer term.”
When the former St. Andrew’s Golf Course in O’Fallon, MO, was sold to developers, it was turned into a subdivision of upscale houses and renamed the Villages of St. Andrew’s. To deal with stormwater runoff, a new retention pond about one-half to three-quarters of an acre was installed below some steep slopes. The engineers’ original plan called for a silt fence over the top of the slopes while they were being revegetated, having been turned into mud during the construction phase.The silt fence presented a problem, though. It would be an unattractive sight for prospective homebuyers to see. Instead, says Thieman, “We talked them into using straw wattles from Earth Saver [of Woodland, CA] because they looked nicer.”
The slopes’ terracing was done with a couple of levels of wattles. They were connected to the pond to slow rainwater down and not allow it to drive sediment into the pond.
“All the slopes needed vegetation. We eliminated the silt fence, and we eliminated the need for an erosion control blanket,” says Thieman. “We just used blown straw and revegetated the site.”
The wattles also provided protection for a retaining wall. Because the entire site was residential, the appearance of the vegetation was significant. Seeding was done with a mix of residential fescue and rye plus a small amount of annual rye to provide some quick cover.
“Everybody wanted a mowable, lush lawn,” Thieman says. “Now it’s fully developed and it [all the yards] looks like a manicured lawn. There’s even some resemblance to the golf course it was.”
The most challenging aspect of the project was “the phasing of it-getting the retention pond built and then getting the erosion and sediment control measures on it right away,” says Thieman.
The soil on the site is a silty loam, with very little clay in it. The retention pond drains into a creek. “We had to be very careful that no sediment went into the creek,” he notes.
Weather was on the side of the workers. The seeding was done in early September, prime seeding season for the St. Louis area.
An erosion control project for the golf course at Bellerive Country Club in St. Louis County was also done with materials and advice from ASP.
It was a small project, covering only 50 feet between two bridges. Its purpose was to protect the stability of the downstream bridge.The creek that runs through a nonplaying area of Bellerive’s golf course is a flashy stream, given to sudden rises and falls. It had been eroding its banks for some time.
“They had done a variety of treatments, but they had continued to have problems with the site, so they called us in, and we gave them options,” says Thieman.
When the work was done in May 2007, the water in the creek was 2 to 3 feet deep.
Fortunately, no rain fell during the three days it took to complete the job.
“Because of the grade, a construction structure downstream held the water [after storms]. We were fortunate it didn’t rain, because the creek would have gotten deeper,” Thieman says.
Turf reinforcement mats from North American Green were used. The mat right against the toe check was a P550 made of polypropylene fiber matrix. Coir logs were placed about 6 feet up, then an SC250 mat of straw and coconut fiber was placed.
“A good mulch mat grows great vegetation,” Thieman says.
A mixture of turf grasses-ryes and fescues-was seeded into the mulch mat going up the slope. Trees were planted along the top of the slope.The most difficult part of the work was dealing with the coir logs. “When coir logs are dry, they tend to float, but they absorb water easily. Trying to get them installed, trying to get them on top of the toe [as they were floating back to the surface] wasn’t easy,” Thieman says.
The coir logs, made by King Fiber (now D2 Land and Water Resource), were 12 inches by 7.5 feet.
“We like to use coir logs because there’s a density to them. Per cubic foot, they weigh 9 pounds,” Thieman adds.
ASP’s solution to Bellerive’s erosion problem has worked beautifully. When Thieman checked the site later, he says, “You couldn’t see it. The site was so well grown with woody vegetation-just what we wanted.”
Golden Ears
The Golden Ears Bridge is a $1.1 billion dollar project involving the construction of a 1-kilometer (slightly more than one-half mile) high-level bridge spanning the Fraser River in the Canadian province of British Columbia. It connects the towns of Langley and Pitt Meadows.The bridge bears a distinctly regional name. The Golden Ears peaks are at the top of Mount Blanshard in Golden Ears Provincial Park, part of the lower Fraser River Valley.Golden Ears Bridge has a clearance of 40 meters (130 feet) and a total length of 2,410 meters (7,910 feet), including approaches. Its three main spans, each 244 meters (801 feet) long, and two shoreline spans, each 122 meters (400 feet) long, measure a total length of 976 meters (3,202 feet).
That distance makes Golden Ears the longest extradosed-a cross between girder and cable-stayed-bridge in North America.Eight pylons stand within the Fraser River. The four tallest pylons rise 90 meters (300 feet) high. The bridge has six traffic lanes and bike- and pedestrian-protected lanes on each side. Two golden eagle sculptures made of metal adorn its highest point.Golden Ears Bridge is part of British Columbia’s TransLink, which was created to ease the movement of traffic throughout the metro Vancouver area. This area is sensitive to the environment, especially for salmon and other species of fish.
TransLink made specific environmental commitments to the Canadian government authorities responsible for fisheries and the environment. Those commitments included strategies to filter stormwater runoff to improve water quality, protect drinking water sources, and provide wildlife habitat.
Every effort was made to minimize the impact on all bodies of water from sediment, concrete, and fuels during construction. Erosion and sediment control and revegetation on the project were done by Denbow of Chilliwack, BC.The project also involved the development of 13 kilometers (just over 8 miles) of roadway and infrastructure in fisheries-sensitive areas adjacent to the Fraser, the world’s richest salmon river.
“There were no special techniques in doing the work, because it was in a sensitive area, but that was the reason we were called in, because it was fish-sensitive,” says Jared Taylor, Denbow’s manager of landscape and environmental services.
“We were called in as needed, sporadically,” Taylor says. Denbow’s crews worked most consistently “at the end of the work, placing the compost blanket. At the height of our work we had 12 people there.”
A large portion of the area was covered with 35,000 square yards of EcoBlanket, a compost blanket from Filtrexx International. Composted bark mulch-3,200 cubic yards’ worth of it-was applied as well.About 23,000 square yards of land were treated using the Terraseeding process from Express Blower. The 2-inch-deep mulch goes on dry and seed is injected into it. A native riparian seed mix with deep-rooted plants to prevent erosion was used. All the medians and boulevards within the project’s area were revegetated through Terraseeding.About 3,200 linear feet of FilterSoxx (filled with compost) from Filtrexx were used around the concrete on bridge pilings to contain the concrete. Both 8-inch and 12-inch sizes of the synthetic fabric type of FilterSoxx were needed.
Denbow is also involved in the processing and manufacturing of landscape growing medium onsite, created from stripping material and ground woodwaste. The project required 19,000 cubic yards of the growing medium
.The biggest challenge of the project was “probably the timing, coordinating everything,” Taylor says. “One advantage of the composting socks is that we can fill them onsite with the blower truck.”Another challenge of working on the project was getting access with the blower truck. “There were pipes and lots of equipment to get through to where we were working,” Taylor explains.
Construction by Bilfinger Berger (Canada) Inc. of Vancouver, BC, began in June 2006. The bridge was opened to traffic in the summer of 2009. It is the first electronic toll bridge in western Canada.
