Tuesday, June 7, 2011

Owasco Flats Restoration

THE OWASCO FLATS RESTORATION PROJECT

In the spring of 2011, Cayuga County received $712,500 in funds from the New York State Environmental Facilities Corporation’s Green Innovation Grant Program for the Owasco Flats Wetland Restoration and Riparian Buffers Initiative. This project will be located on City of Auburn owned land off of Route 38 in the Town of Moravia. A portion of the Owasco Inlet will be reconnected with its floodplain with water control structures and the water will flow into existing and created wetlands to filter out nutrients and sediment. Riparian buffers will also be planted along agricultural drainage ways and along the Owasco Inlet to further reduce nutrients and sediment inputs. This work will also improve habitat for invertebrates, reptiles, amphibians and birds while reducing phosphorus and sediment that reaches Owasco Lake. The overall objective of restoration efforts is to reduce phosphorus and sediment loads to Owasco Lake. (Link to the Auburn Citizen article from 4/26/11:) http://auburnpub.com/news/local/article_4f8df484-6fb2-11e0-8c10-001cc4c002e0.html

Since its inception, the Owasco Lake Watershed Association has supported the restoration of the Owasco Flats. OWLA has helped finance land-use studies, road improvements and informational sign placement in this special area. Continuing this support, we will be soon be mailing all OWLA members with a copy of the inaugural newsletter from the Owasco Flats Nature Reserve.

HISTORY OF THE OWASCO FLATS

The Owasco Flats encompass approximately 1,500 acres of land within the Owasco Inlet floodplain. The Owasco Flats occur within the valley of the Owasco Inlet. As the name suggests, the topography of the Flats is almost level, with a change in elevation of less than 20 feet over the 2.8 miles between the southern end of Owasco Lake and the northwestern portion of the Village of Moravia and across the approximately 0.6-mile valley width. Land cover within the Flats includes swamps, forest, emergent marsh, active agricultural fields, successional old field communities, and sparse residential development. The Flats support 11 identified ecological communities and provide habitat for a wide diversity of plants and animals, including a number of state and federally protected species.

Almost the entire Owasco Flats and roughly half of the Village of Moravia occur within a 100-year floodplain. Natural functions of a floodplain include temporary storage of floodwaters, attenuation of peak flows, water quality improvement, and groundwater recharge, among many others. When undisturbed by human activities, the low lying, flat expanses of floodplains reduce sediment and nutrient loading by slowing down the velocity of water as it approaches the receiving water body, allowing sediment to settle and nutrients to be absorbed by floodplain vegetation.

However, the functionality of the floodplain wetlands has been compromised by human activity. Prior to the onset of agriculture, the Flats most likely consisted of a forested ecosystem that did not contain the present-
day diversity of ecological communities that have inadvertently resulted from the area’s agricultural history (e.g., clearing areas for agricultural fields that have since been left fallow). As the area slowly reverts to a forested landscape, a reduction of the present-day diversity of plants and animals may occur.

Prior to departing the Owasco Lake Watershed in the late 1700’s, the Cayuga Indians had an effect on the Owasco Flats ecosystem. The Cayugas subsisted on hunting and fishing, and cultivating corn, beans, pumpkins, tobacco, sunflowers, hemp, and fruit trees. Clearing and cultivation of the Owasco Flats by Native Americans created a rich meadowland throughout much of the area. The Village of Moravia was originally called Owasco Flats but was re-named Moravia in 1819.

The Southern Central Railroad was completed and opened in 1869. It passed through the western portion of the Town of Moravia along the valley of the Owasco Inlet and crossed the Inlet at two locations. The railroad made significant efforts to control the course of the Owasco Inlet.

The City of Auburn began managing the lake levels in 1886. As a result of industrial water use, the lake levels were drawn down significantly during the summer season in the 1800’s/early 1900’s before electricity became available from other sources. The summer drawdowns provided drier soils for agricultural use in the Flats during this time period. In some areas, additional wetlands have been drained for the purposes of agricultural use.

In 1938, aerial photographs reveal that approximately 70% of the land was cleared for agricultural use. Since that time, some of the wetter land has been allowed to revert back to forest and shallow marsh so that now only about 25% of the land is classified by the Cayuga County Real Property Services database as agricultural. Much of the land that was apparently actively engaged in agriculture in 1938 is now used intermittently for pasture, hay or is fallow; the rest of the Flats today is covered by forest (30%) and open marshland (20%).

In addition, the Owasco Inlet was hydrologically separated from the Owasco Flats floodplain as a result of 1948 and 1960 Army Corps of Engineers flood control projects along the Owasco Inlet, Mill Creek, and Dry Creek in the Village of Moravia. “Improvements” to the Inlet included widening and straightening of the channel, enlargement of bridge openings, and removal of trees, gravel bars, and debris jams. Today, the Flats’ wetlands no longer filter floodwaters before they enter Owasco Lake to the extent that they would under more natural conditions, thereby increasing sediment and nutrient loads and impairing the water quality of the lake.

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