Iowa Water Features

An Overview of Iowa's Rivers and Lakes

Largest and Most Notable Rivers & Lakes

Iowa is framed by two great boundary rivers — the Mississippi River on the east and the Missouri River on the west — with the Big Sioux River forming part of the northwest boundary. Interior drainage is led by the Des Moines River (with Raccoon branches), the Cedar–Iowa system, the Skunk River, and northern tributaries like the Wapsipinicon, Turkey, Upper Iowa, Maquoketa, and Shell Rock. Western basins include the Little Sioux, Boyer, Nishnabotna (East & West), Nodaway, and Chariton. Signature lakes include the Iowa Great Lakes (West & East Okoboji, Big Spirit), Clear Lake, and major reservoirs: Lake Red Rock, Saylorville Lake, Coralville Lake, Rathbun Lake, Storm Lake, Big Creek Lake, and Lake Manawa.

Water Sources & Flow

Flows are driven by rain and snow across glacial till plains and loess hills. Most interior rivers meander southeast toward the Mississippi; western streams trend south to the Missouri. Locks and dams on the Upper Mississippi maintain navigation pools; interior rivers are generally not navigable by large vessels.

River & Lake Types

Iowa features:

• Glacial‑formed natural lakes in the north (Okoboji chain, Big Spirit, Clear Lake).
• Large multipurpose reservoirs (Red Rock, Saylorville, Coralville, Rathbun) for flood control, water supply, and recreation.
• Oxbow and backwater complexes along the Mississippi and Missouri.

Recreation

Boating and fishing thrive on the Okoboji–Spirit lakes, Clear Lake, Storm Lake, and the big reservoirs. Paddling highlights include the Upper Iowa, Turkey, Wapsipinicon, Maquoketa, and reaches of the Raccoon and Cedar.

Flooding & Water‑Quality

River flooding affects many basins (levee overtopping, backwater on major pools). Nutrient runoff management is a priority in agricultural watersheds feeding the Mississippi and Missouri systems.

Iowa Rivers, Lakes, Streams and Water Features