From the earliest days of settlement, the wetlands of southern Wisconsin were considered wasted land. While farmers might access them to hunt a few ducks, they were otherwise useless. The wetlands we see today are a shadow of their former glory. In fact, many of the creeks that flow freely today did not exist until they were created by dredges in the late 19th and early 20th centuries. These creeks drained the wetlands which allowed them to be farmed.
Even after ditching, these lands were often not productive. So, typically, the next step was tile draining. Tile drains are perforated pipes buried about eighteen inches beneath the surface and graded so the water that drains into them flows down gradient to a ditch, creek, or river. The tiles are laid out in parallel lines to efficiently remove excess water from an entire field. The use of ditches and tiles has opened up thousands of acres of former wetland to agriculture, but this has come at a price.
The hydrology of southern Wisconsin has been radically altered. Where once there were marshes and swamps, there are now streets, parking lots, farm fields and ditches. When rain falls on farmland, it moves quickly from field to ditch, from ditch to creek, from creek to river. When it falls on a paved surface, a pipe quickly takes it to the nearest stream. Today’s rivers run dark with silt and green with algae from excess nutrients. Moreover, they carry a far higher volume of water and flood much more readily than in earlier times. The great value that has been derived from the reclaimed wetlands turned farm fields, has been largely offset by the great losses, both financial and otherwise, that have resulted. Flooding is a major side effect of wetland destruction. And when the waters of lakes turn green and smelly in July, it is also in part, a result of these profound changes. This has cost millions of dollars and continues to exact a toll year after year.
Historically, these rivers and wetlands were incredibly productive. The Rock River was named because of its rocky bottom, clearly visible through ten or fifteen feet of water. Sturgeon, pike and all manner of smaller fish were common. When heavy rains came, the wetlands slowly filled up, then slowly released the water into the ground. The water migrated underground for miles, emerging in swales and valleys in what is called “base flow.” Base flow, having moved through the soil, is cold and clear. Today, much of the water in our rivers is surface flow full of silt, nutrients, pollutants, and heat. Carp and suckers are common. Sturgeon are not.
Wetland restoration can be a complicated process. The most critical variables are hydrology and invasive species. Careful attention to these issues is absolutely critical. If hydrology is problematic, the input of a civil engineer is required. Reed canary grass is the most pernicious invasive species and is frankly very difficult to control once established. For existing natural areas infested with RCG, a regimen of carefully formulated and timed herbicide applications along with carefully timed prescribed burning is required.
If a site has appropriate hydrology and is not overwhelmed by invasive species, the process becomes relatively straight forward. For certain wetlands that are not consistently inundated, such as wet prairies and sedge meadows, seeding is very effective. For emergent and marsh areas that are consistently inundated, live plants must be installed and protected from geese and possibly muskrats. However, once these plants become established, they will spread rapidly.
One of the greatest things about wetland restoration is how quickly wildlife responds. Usually, even within the first season frogs will breed and birds will nest. Check out this link to one of the most impressive wetland restoration projects we have been involved in. http://www.senecameadows.com/wetlands.php