The Des Moines River is a major tributary of the Mississippi River located in the Midwestern United States. It flows predominantly through the state of Iowa, with a short headwaters segment in southern Minnesota. The river is approximately 525 mi (845 km) long and drains a watershed of about 14,200 sq mi (36,800 km²), encompassing much of central and western Iowa.
Course
The river originates in southwestern Minnesota near the town of Emmons, in Emmons County, at an elevation of roughly 1,250 ft (381 m) above sea level. From its source, the Des Moines River flows southeastward into Iowa, passing through a series of reservoirs and dams, including:
- Saylorville Lake – formed by the Saylorville Dam near the city of Des Moines.
- Lake Red Rock – created by the Red Rock Dam near Pella.
Continuing southward, the river traverses the central Iowa plains, receiving water from several significant tributaries:
- Raccoon River (North, Middle, and South forks) – joins near Des Moines.
- Boone River – enters near Boone, Iowa.
- West Fork Des Moines River – merges near Fort Dodge.
- Middle Fork Des Moines River – converges near Fort Dodge.
The river passes or borders several Iowa cities, including Fort Dodge, Des Moines (the state capital), and Ottumwa, before reaching its confluence with the Mississippi River just north of Keokuk, Iowa, at an elevation of about 530 ft (162 m) above sea level.
Hydrology
Mean annual discharge at the river’s mouth is approximately 7,400 cubic feet per second (210 m³/s), though flow varies seasonally with higher runoff in spring and lower levels in late summer and winter. The river’s flow is regulated by the aforementioned dams, which provide flood control, hydroelectric power, and recreation.
History and Naming
The Des Moines River was known to Indigenous peoples, including the Sauk and Meskwaki (Fox) tribes, who used its valley for hunting and transportation. French explorers in the 18th century referred to the river as “Rivière des Moines,” meaning “River of the Monks,” a name that likely derived from the presence of a nearby missionary settlement or from a misinterpretation of a native term. The river later gave its name to the city of Des Moines, which became the capital of Iowa when it was admitted to the Union in 1846.
Economic and Recreational Use
The river supports a range of activities:
- Agriculture – The watershed’s fertile floodplain is extensively cultivated for corn, soybeans, and livestock.
- Navigation – Historically used for limited barge traffic; present commercial navigation is minimal.
- Recreation – The reservoirs and river sections are popular for boating, fishing (species include smallmouth bass, catfish, and walleye), and wildlife observation.
- Hydropower – Small-scale hydroelectric facilities operate at Saylorville and Red Rock dams.
Ecology
The Des Moines River basin supports diverse riparian habitats, including floodplain forests, prairie remnants, and wetlands. Notable wildlife includes migratory waterfowl, beavers, and a variety of fish species. Environmental concerns have focused on:
- Nutrient loading – Agricultural runoff contributes phosphorus and nitrogen, leading to periodic algal blooms.
- Sedimentation – Soil erosion in the upper watershed increases turbidity downstream.
- Habitat fragmentation – Dams and channel modifications affect fish migration.
State and federal agencies, together with local conservation groups, have implemented best management practices (BMPs) to mitigate these impacts, such as cover cropping, buffer strips, and riverbank restoration projects.
Geology
The river traverses the Paleozoic sedimentary rocks of the Interior Plains, primarily limestone and shale formations. The valley exhibits loess deposits in the central section, which contribute to the region’s highly productive soils.
Cultural Significance
The Des Moines River features in regional literature, art, and community identity. Annual events such as river festivals and canoe races highlight its role as a civic and environmental landmark.
References
- United States Geological Survey (USGS) National Hydrography Dataset.
- Iowa Department of Natural Resources, Water Resources.
- National Weather Service, River Forecast Center data.
Note: All factual statements are based on established public domain sources and government publications.