Upper Lake Oahe
Watershed Hydrology
The Upper Lake Oahe watershed (HUC 10130102) covers an area of approximately 14,000 square miles in South Dakota and North Dakota. The hydrology of the region is characterized by the Missouri River and its tributaries, including the Grand River and the Moreau River. The region experiences significant snowfall during the winter months, which contributes to the surface water in the spring and summer. The Lake Oahe reservoir, which was created by the Oahe Dam on the Missouri River, provides water for irrigation, hydroelectric power, and recreation. The reservoir also contains significant levels of sediment and nutrients, which can impact water quality downstream. Interesting climatic facts include the region's susceptibility to drought and the increasing frequency of extreme weather events. In recent years, the area has experienced both record-breaking snowfall and prolonged periods of drought.