The San Gabriel Watershed covers an area of approximately 1,281 square miles in Southern California. It is a critical source of water for the region, supplying water to over 3 million people. The hydrology of the watershed is influenced by the San Gabriel Mountains, which receive significant amounts of precipitation and snowpack during the winter months. This snowpack gradually melts during the spring, providing a reliable source of surface water. The watershed also contains several reservoirs, including the San Gabriel Reservoir, which is used for drinking water and recreation. Interesting climatic facts include the region's Mediterranean climate, with hot, dry summers and mild, wet winters. However, trends in recent years suggest a decrease in precipitation and snowpack, which has led to concerns about water scarcity and the need for effective water management strategies.