The Oak Orchard Twelvemile Watershed (HUC 04130001) covers an area of approximately 239 square miles in western New York. It is primarily a rural agricultural region, with a mix of forested and developed areas. The watershed's hydrology is influenced by several small streams that converge and flow into Lake Ontario. The region experiences a moderate snowfall, with an average snowpack of around 50 inches during the winter months. Surface water quality is generally good, with low levels of pollutants and only a few areas of concern. There are several small reservoirs in the watershed, which are used for water supply and recreation. Climatically, the region experiences four distinct seasons, with average temperatures ranging from the low 20s in winter to the mid-70s in summer. In recent years, the region has seen an increase in extreme weather events, including heavy rainfall and flooding.