The Walla Walla Watershed, located in southeastern Washington and northeastern Oregon, covers a total land area of 1,980 square miles. The area receives an average annual precipitation of around 20 inches, with a significant portion of it coming in the form of snowfall in the winter months. The watershed is fed by several small streams and tributaries, which eventually flow into the Walla Walla River. The river is the primary source of surface water in the region and is also used for irrigation purposes. The watershed is home to several reservoirs, including Bennington Lake, which was created by the Bennington Dam. The reservoirs provide water for irrigation, municipal, and industrial uses. The area experiences hot summers and cold winters, with average temperatures ranging from 30°F to 90°F. The climate in the region is changing, with increasing temperatures and more extreme weather events being observed in recent years.