The Lake Chelan Watershed (HUC 17020009) covers approximately 378 square miles in north-central Washington State. The area is characterized by a Mediterranean climate with hot, dry summers and cool, wet winters. The watershed is fed by snowmelt from the surrounding Cascade Mountains, which provides surface water to Lake Chelan, a natural glacier-fed lake that is over 1,400 feet deep. The lake water is used for irrigation, hydroelectric power, and recreation. The snowpack in the watershed varies from year to year, with the deepest snowpacks occurring in the higher elevations. The reservoir constituents of Lake Chelan include dissolved oxygen, pH, turbidity, and temperature, which are monitored to maintain water quality. Interesting climatic facts and trends in the area include an increase in temperatures and a decrease in snowpack over the past few decades, which has implications for the local ecosystem and water supply.