URBANIZATION AND WATERSHED HEALTH: A CASE STUDY OF THE SOUTH FORK OF BEARGRASS CREEK, LOUISVILLE, KENTUCKY

The urbanized Beargrass Creek watershed covers approximately 60 square miles in Louisville, KY. Many sections of the stream are channelized and at several different points the creek comes in to contact with sewage overflow gates. These overflow gates are connected to the combined sewer system of Louisville, and are used to relieve stress on the system when heavy rains occur. The aim of this study was to determine how the urbanization of this waterway, in combination with natural fluctuations in temperature and rainfall, affected basic parameters of stream health. The field area of this study is the South Fork of Beargrass Creek, located directly next to Bellarmine University. This stretch of stream exemplifies the changes that urbanization and channelization can have in a stream environment. Specifically, this section of the creek is partially channelized, receives direct sewage overflow from the combined city sewer system, and is surrounded by many impervious surfaces like busy roadways and the multiple parking lots associated with the university. To quantify some of the effects that an urbanized environment has on this watershed, we gathered turbidity, water temperature, dissolved oxygen, alkalinity, ammonia, carbon dioxide, chloride, hardness, nitrite, and pH levels on a bi-weekly basis at the three different sampling sites over a five month period from June to October, 2011. The results from the three sampling sites were then compared to determine the degree to which this stretch of Beargrass Creek had been affected by urbanization, and specifically establish if the proximity of a sewer system discharge gate has any impact on localized creek health. With the results of this study it will be possible to make recommendations on how to improve the health of the Beargrass Creek watershed and lessen the negative impact that the surrounding community has on the creek and surrounding ecosystem.