STRAIGHT RIVER MARSH:
Wetland and prairie restoration
The Straight River Marsh is a sight of restoration because the wetland was previously diverted into a ditch for agriculture, but as time progressed it was realized that the marsh would control flooding, filtering water and sediments better than the human-made modification.
Knowing the reasons that lead to Straight River Marsh restoration allows one to recognize its significance ecologically while giving it identity with reference to time. The Straight River region has experienced frequent flooding because its soils are composed of peat and used for corn and soybean agriculture. Since 1915, farmers have dug ditches to drain fields and pasture. Peat soils break up with time, causing fields to sink and overload the ditch with sediment. Water overloads from highland areas over flood the ditches and make them ineffective (Environmental Defense). This was realized in the 1980s, especially by downstream landowners, giving incentive for to remove the ditch and allow the native wetland to reform. Before agriculture the Straight River Marsh was an old migratory bird stopover, whereby its restoration has dramatically increased their current frequency (Frank). The Straight River Marsh area has changed over the years; it is a marsh that has been drained and reclaimed due to an unsatisfactory alternative use of the area.
The Straight River Marsh is a a basin wetland surrounded by mesic prairie. The water and sediment it filters is a part of the ground and river system of the Straight River Marsh, which connects to and becomes the Cannon River in the Cannon River Watershed.
The Straight River flows from Owotanna to
Faribault, about 30 miles through southeast MN (Environmental Defense).
Although the Straight River Marsh is located in the Straight River
Watershed, it is near its northern border with the Cannon River
Watershed. The Straight River becomes the Cannon River at the southern
part of the Cannon River Watershed, near Faribault. The Straight River
Marsh is a basin wetland
surrounded by mixed
height and tall
grass prairie in Steele County, MN; ten miles long and four miles
wide (Frank 2004). The wetland supports migratory waterfowl such as
tundra swans, sandhill cranes, canvasbacks, pintails, wigeons, wood
ducks, teal, mergansers, herons, snipes, bald eagles and owls.
(Environmental Defense). The ditch system does not adversely affect all
landowners the same, therefore restoration of the entire basin has not
been achieved. However, the fact that it is a
basin wetland makes it ideal for restoration. When water is allowed to
divert on its original pathway, the basin refills in a seed-retaining
basin that produces plant growth (Hammer 1992). Although the ditch
still remains, the wetland has allowed flooding to be controlled.
The Straight River Marsh was physically an ideal site for restoration because it was formerly a depression, or basin wetland.
Restoration takes time and energy, and
knowledge of this process gives understanding to the significance of a
place in its own context. Currently, 24 landowners and 1400 acres of
land have been restored since 1995. It takes one year to close a
property easement for restoration, one year to restore, and two or
three years for visible results. The Wetland Reserve Program (WRP)
provides funding for the initial 30-year easements, which are put into
the Reinvest in Minnesota easement program for permanency. Wetland
restoration requires removal of the underground tiles that channel
water away from the wetland, followed by native wetland seeding. Upland
prairie restoration involves seeding of native prairie species
(Environmental Defense). In basin wetlands buffers are important
because the main water source is surface highland runoff. The prairie
serves as a buffer zone that filters excess sediment and chemicals
before they reach the wetland, preventing wetland eutrophication while
providing habitat for wildlife. A buffer should be positioned from the
wetland perimeter to the periphery of the vegetated highland area (Shaw
2000; Marble 1992).