The Upper Grand Watershed (HUC 10280101) covers approximately 1,120 square kilometers in south-central Ontario, Canada. The watershed is home to several significant rivers, including the Grand, Irvine, Conestogo, and Speed Rivers, which provide important water resources to the surrounding communities. The hydrology of the Upper Grand Watershed is heavily influenced by precipitation, which falls mainly as rain in the summer and as snow in the winter. The watershed receives an average of approximately 1,000 mm of precipitation per year. Snowpack in the watershed can accumulate up to two meters in depth during the winter months. Surface water in the watershed is heavily regulated, with several large reservoirs, including the Guelph Lake Reservoir and the Conestogo Lake Reservoir. These reservoirs are used for drinking water, flood control, and recreation. Climatically, the Upper Grand Watershed experiences a moderate continental climate, with warm summers and cold winters. Over the past century, the area has experienced a significant increase in annual precipitation, particularly in the winter and spring months. This increase in precipitation has been attributed to climate change.