Raccoon River, IA

The Raccoon River is a 30.8-mile-long (49.6 km) tributary of the Des Moines River in central Iowa in the United States. As measured using the longest of its three forks, its length increases to 226 miles (364 km). Via the Des Moines River, it is part of the watershed of the Mississippi River.

During the Great Flood of 1993, the Raccoon River flooded the water treatment facility of Des Moines, shutting off the city's supply of drinking water.

The Raccoon River flows for much of its length as three streams:

The North Raccoon River is, by far, the longest of the three, at 196 miles (315 km). It rises north of Marathon in northeastern Buena Vista County and initially flows southwardly into Sac County, where it turns southeastward for the remainder of its course through Calhoun, Carroll, Greene and Dallas counties. It passes the towns of Sac City, Jefferson, Perry and Adel. The Adel Island dam in Adel is the only dam along its course.

The Middle Raccoon River, 92 miles (148 km) long, rises in northwestern Carroll County and flows generally southeastwardly through Guthrie and Dallas counties, past Carroll, Coon Rapids, Springbrook State Park, Panora, Linden, and Redfield. The three dams located along its course are the Lake Panorama dam and the Lennon Mill dam at Panora, and the Redfield dam at Redfield. Even though the Lake Panorama dam, completed in 1970, was built for recreational purposes only, it has provided some additional benefits by controlling flooding along the Middle Raccoon River. The Middle Raccoon River flows into the South Raccoon River about 1 mile (1.6 km) south of Redfield.

The South Raccoon River, about 72 miles (116 km) long, rises in northeastern Audubon County and flows generally southeastwardly through Guthrie and Dallas counties, past the town of Guthrie Center. South of Redfield, after the Middle Raccoon River flows into the South Raccoon River, a flow gage operated jointly by the United States Army Corps of Engineers (Rock Island District), the United States Geological Survey (Iowa District), and the Iowa Department of Transportation provides data about potential flooding threats.
 
The north and south forks join in Dallas County just west of Van Meter, and the Raccoon River flows generally eastwardly into Polk County, past Walnut Woods State Park and West Des Moines. It joins the Des Moines River just south of downtown Des Moines.