The Owasco Flats is a 1500-acre wetland complex adjacent to the southern end of Owasco Lake, to the north of the village of Moravia and bordered by Route 38 and Rockefeller Road. Of this 1500-acres, there are several different ecosystems, including swamps, marshes with cattails and willows, forested wetlands and cropland.

In the 1940s, the Army Corps of Engineers widened and straightened the main channel of the Owasco Inlet through the wetland complex. They did this based on old methodologies in order to control flooding. Unfortunately, these actions have resulted in an increase in the flow of the river, causing a variety of issues.

Floodplains are important to the proper functioning of a river system.

During periods of high water, like heavy rainstorms or fast snow melts, the water in a river peaks and starts to “spill over” into its floodplain. In a properly functioning floodplain, plants like trees and shrubs slow the flow of the water.

With the water slowed, sediment is able to settle out of the water, bringing with it nutrients like phosphorus and nitrogen.

These trees and shrubs of the floodplain also help to minimize erosion, especially along the stream bank.

But, it is important to remember that even properly functioning floodplain forests will experience some erosion, which is proportionate to the amount of rain and/or snowmelt and how quickly it occurs, how saturated the soil is and the type of soil.

When floodplain forests are removed, it can have detrimental effects on the river ecosystem. First, when there is a flooding event, water runs over open spaces, like fields or lawns.

As the water runs over the open ground, it picks up things like phosphorus, nitrogen, fertilizers, herbicides, pesticides and bacteria. So, as this water re-enters the river, it contains these nutrients and chemicals.

On the other hand, when the river is separated from the wetland and unable to “spill over,” the velocity and amount of water flowing increases, causes excessive erosion.

Erosion will cause an increase in sediment in the stream. When the floodplain is lacking vegetation along its banks, soil is easily eroded because there are no roots holding it in place.

This causes the water to be muddy and brown. Very muddy water is harmful to fish because it can clog their gills.

Too much sediment in the water is also bad for fish eggs because it can smother them.

Not only does the high amounts of sediment decrease the quality of the river, but it also has a devastating effect on the water body it drains into.

In the case of the Owasco Inlet, all of the water drains into Owasco Lake, which serves as a drinking water source for more than 50 percent of the people of Cayuga County.

In June of 2007, the Finger Lakes Land Trust (www.fllt.org) released a report about the Owasco Flats titled “The Owasco Flats: Comprehensive Planning and Stakeholder Survey Project.” To view a copy of the report, visit www.cnyrpdb.org/fingerlakes/.

Jessica Miles is the Owasco Lake Watershed inspector.