226— Analysis of Soil at a Flooding Site in Avon, NY

A residential area in East Avon frequently floods in response to rainfall or snowmelt events and the water remains pooled in place long afterwards. This study seeks to determine the cause of the flooding. Soil samples were collected from several locations at the site and analyzed to determine the array of grain sizes present. It was determined that approximately 47% of the sediment at the site is smaller than 63 microns, which is the threshold for silts and clays (mud), meaning that approximately 53% of the sediment is sand sized or larger. The large amount of smaller grain sizes, combined with poor sorting within the soil, result in small pore spaces and a lack of connectivity between the pores. This makes it difficult for the soil to drain water, and hence, ponding occurs.