The Pecatonica Watershed, located in Wisconsin and Illinois, has a land area of approximately 2,360 square miles. The hydrology of the watershed is influenced by the freeze-thaw cycle, which causes fluctuations in streamflow during the winter months. The watershed receives an average of 36 inches of snow each year, with the heaviest snowfall occurring in January and February. Surface water in the watershed includes numerous streams and rivers, including the Pecatonica River, which flows through the heart of the watershed. Reservoirs within the watershed are used for both flood control and recreation. Interesting climatic facts include the fact that the area experienced record-breaking rainfall in the summer of 2018, leading to flooding in many parts of the watershed. There has also been a trend of increasing winter precipitation in recent years.