The Chicago watershed (HUC 07120003) covers an area of approximately 2,500 square miles and is primarily a flat, urbanized region. The hydrology of the watershed is dominated by the Chicago River system and Lake Michigan. The snowpack in the region varies depending on the severity of winter weather, but can impact water levels in the rivers and reservoirs during the spring melt. Surface water in the watershed is heavily influenced by urbanization and pollution, which can negatively impact aquatic ecosystems. The reservoirs in the watershed are primarily used for drinking water and recreational purposes, and their constituents are closely monitored to ensure water quality. The region experiences a humid continental climate with four distinct seasons, and has seen an increase in average temperatures and precipitation over the past few decades. Climate change is expected to continue impacting the region, with potential implications for water resources, agriculture, and infrastructure.