May-June 2006

Wetlands

Lose or restore?

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By Roberta Baxter

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The Chelsea Green Space and Recreation Committee, NOAA, the City of Chelsea, and other local, state, and federal agencies and corporations came together to restore and maintain the wetlands.

According to Eric Hutchins, National Marine Fisheries habitat restoration coordinator, the first step was to persuade the Highway Department of its responsibility in the project. Stormwater runoff from the highway was piped into the salt marsh and sediments were clogging the marsh. In some places, the sediment was 5 feet deep. Debris such as shopping carts and trash also littered the marsh.

The Corporate Wetlands Restoration Partnership, pioneered in Massachusetts, led the way for this project. Local communities lacking matching funds depend on private companies to provide money. For the Mill Creek Restoration Project, five companies donated money or services, predominately in in-kind donations. Eastern Analytical offered sediment sampling; Charter Environmental handled the excavation; Waste Management waived many of its fees to truck the contaminated sediment away; ERM coordinated sediment sampling; and BSC Group took on permit coordination. Without the donations of these companies, the project would not have been feasible.

Before the project began, the grade of Mill Creek had built up to a high enough level that only two tides a month arrived in the upper reaches. Many sections received water only during stormwater events, so no fish could survive in the environment. The animals seen in the area were rats and skunks. The plant life was almost entirely invasive species.

The surface grade was reduced by 6 to 12 inches, allowing daily tidal flow. Pannes and pools were incorporated in the design to encourage diversity of wildlife, such as salt marsh minnows. Approximately 1,200 cubic yards of invasive plants were ripped up and disposed of. Planting of native species will occur in spring 2006.

Education of schoolchildren and nearby residents increases the likelihood that they will value the wetlands and fight to keep the area healthy. Schoolchildren are monitoring water quality and soil salinity levels and observing diversity of wildlife.

The project appears to be healing the marsh. Egrets and great blue herons have been sighted.

Going Natural in Virginia
In 1995, the EPA, the Natural Resources Conservation Service, the Fish and Wildlife Service, the Army Corps of Engineers, and NOAA issued “Federal Guidance for the Establishment, Use and Operation of Mitigation Banks.” This document has provided the guidelines for wetland mitigation banks. Marsh Resources Inc. is one of the largest mitigation banks, and it has contracted with Greenhorne & O’Mara Inc. for several projects in Virginia.

James Ingram, senior environmental scientist for Greenhorne & O’Mara, has managed several of the projects in the last six years, working in almost every Potomac watershed in Virginia. As project manager, Ingram identifies the potential mitigation sites, negotiates with landowners and drafts option agreements, performs technical studies and testing, and designs the project. The technical studies include Section 106 clearance with the state historical office because of possible artifacts from Civil War battles or earlier times.

Once a site has been identified, Ingram negotiates with landowners for either easement for the project or purchase of the site. Most of the areas were historically wetlands that have been drained by farmers. Some still are so wet most of the year that farmers use them as “summer pasture” during July, August, and September, the only months they are dry enough. One site that Ingram recently bought flooded frequently, and stormwater had deposited woody debris. The conditions made the site difficult for the farmer to use but invaluable as wetlands.

Extensive onsite soil testing provides clues to the historical wetland properties of each site. Ingram says he believes in doing minimal work to undo what human activity has done to a site over the last 200 years. If the right site is chosen, “We don’t do a lot of earthwork,” he says. Minimal disturbance will push a site back to wetland status. “The less push needed, the better the site is.”

Farmers have often dug ditches or installed French drains on the upland side of a property to handle the seepage. Ingram says that by choosing sites that were once wetlands, the areas can be restored easily. For many sites, simply installing ditch plugs provides the needed water for wetland restoration.

Another technique used in the restoration process is root raking. Removing the turf layer and restoring hydrology exposes seed banks, and native herbaceous plants begin to grow. For most projects in Virginia, trees and shrubs are planted to restore those species, but other seeds are present already.

Once plant life has been restored, animal life follows. Amphibians, eagles, coyotes, fox, deer, and wood duck return to the wetland. One benefit of the approach, according to Ingram, is that these areas with tall plants are not attractive to Canada geese, a nuisance species for the region. Canada geese require large open spaces, which are not found in these wetlands. The habitat is more conducive to wood ducks and other native birds.

Working with Ingram on several projects was Gary Jellick of Acorn Environmental Inc. The Bender Farms project involved an active dairy farm. Cows roamed near and in the stream, Cedar Run, and sediment flowed into the creek during storms. For the farmer, the wet field was more trouble than it was worth, according to Jellick. The EPA requested that some pretreatment be done for the water before it entered the wetlands that were being restored, so a ponded area was created to capture the first flush of stormwater. Shrubby plants, such as buttonbush, were planted to increase the uptake of the nutrient load. The pond is only about 6 inches deep to provide a good growth environment for the shrubs. Two outlets at grade level of the pond provide overflow into the wetlands during rain events. The setup mimics natural wetlands.

The Howser’s Branch project was undertaken at the request of the Mount Zion Church Preservation group. The property was slated to be developed, but the group wanted to preserve the church and have a place for cavalry reenactment troops to practice. They sold an easement for 45 acres of floodplain that had been used to grow hay. By waiting until the wetland credits through the mitigation bank were sold, they received a higher price for the land. According to Jellick, an acre of wetlands usually equals one credit. If the project is preserving an existing wetland, 10 acres equals one credit; for upland components needed for the project, the amount is 20 acres for one credit. Designs for the project have been submitted to agencies, and construction is to start soon.

Jellick states that the process is all about how much water comes into a site, how much leaves, and how fast. Ingram mentions what he calls “Jellick’s 180 Rule”—you face the stream and then turn around to see what the land 180 degrees away is like—adding, “We let the information confirm the design, not drive the design.”

Dredging From Kansas City
It may seem strange to find a dredging company in Kansas City, MO, but that’s where Dredge America Inc. is located. President Dan McDougal says the advantage is that the company can have a dredge anywhere in the country in about two hours because of its central location. The company owns five portable dredges. One project that Dredge America tackled was on the backside of Galveston Island in Texas.

Photo: Eric Hutchins, National Marine Fisheries
Observing the Mill Creek wetlands before restoration

Wave action was causing severe erosion of the bank, so Dredge America personnel installed 9,000 feet of geotubes to create a backwater. Then marsh buggies were used to create a matrix for plant growth. The area was replanted with wetland plants, and the plant life is thriving. This project was contracted by the Texas Parks and Wildlife Department.

Along the Mississippi Gulf Coast, a wetland channel had filled in with sediment, obstructing flow from uplands into the gulf. Dredge America was contracted to dredge an 8-foot-wide channel. Managing the job without negative impact on the wetlands is the goal of Dredge America. If the project is designed properly with the geotubes placed correctly and the sediment pumped behind them, the wetland area is stabilized even during high tides, according to McDougal.

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“Once dredging was seen as a bad thing,” McDougal says. Now people have seen that it can be a useful tool for wetland preservation and restoration. Once dredging is finished, the wetland habitat begins to recover and the number of species just explodes. Dredging can create channels for recreational or industrial use and provide good habitat.

Minnesota Wetlands
North American Wetland Engineering LLC (NAWE) of White Bear Lake, MN, has designed and constructed several created wetlands and restored others. According to Vice President Scott Wallace, one very successful project began in 1997. Rahr Malting Co. needed a waste discharge permit to expand the company’s operations. However, the Minnesota River was limited from any more point-source discharges. NAWE developed a nonpoint-source trading program and proposed it to the Minnesota Pollution Control Agency. The trade stated that for every pound of organic nutrients discharged, 2 pounds of nonpoint-source organics would be reduced. Next Page >

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