When people talk about flooding in Ottumwa, the flood of 1851 often gets most of the attention. It was an extraordinary event, remembered as one of the greatest floods in the history of the Des Moines River Basin.
But 1851 was far from the last time the river threatened Ottumwa.
Over the next century, the Des Moines River would rise again and again, testing homes, businesses, bridges, railroads and the people who lived along its banks. Three floods — 1903, 1947 and 1965 — help tell the story of how Ottumwa changed while the river remained much the same.
The Flood of 1903
The flood of 1903 was one of the first major Des Moines River floods for which reliable measurements were available. The U.S. Army Corps of Engineers notes that actual flood records began in 1903, although historical accounts document major floods going back decades earlier.
The May and June 1903 flooding followed weeks of extremely wet weather. Heavy rain between May 24 and May 31 pushed rivers throughout the region out of their banks.
The flood was not limited to Ottumwa or even Iowa. The same storm system produced serious flooding across several watersheds, including the Mississippi River.
Farther downstream, the flood was particularly powerful. At Keosauqua, the estimated peak discharge of the 1903 flood was later revised to approximately 146,000 cubic feet per second.
For Ottumwa, 1903 was a different world than 1851.
The city had grown considerably. The railroad had arrived in Ottumwa in 1859, and additional railroads later made the community an important transportation center.
That meant the river was no longer threatening a small frontier settlement.
By 1903, Ottumwa had factories, businesses, homes, railroad infrastructure and a growing population — all concentrated around a river that could still rise with little regard for what had been built beside it.
The flood also marked an important change in how flooding was documented. Unlike the flood of 1851, which is known largely through historical accounts and physical evidence, the twentieth century brought increasingly systematic river measurements.
In other words, Ottumwa was beginning to keep better records of something residents had already learned the hard way:
The river could not be ignored.
1947: When the River Climbed Above 21 Feet
Nearly half a century later, Ottumwa experienced another extraordinary flood.
Federal records show the Des Moines River at Ottumwa reached 21.1 feet on June 7, 1947. Another crest that month reached 21.0 feet on June 15.
The 1947 flooding was significant across the Des Moines River Basin. The Army Corps of Engineers describes 1903 and 1947 as among the most damaging basinwide floods since 1851.
Imagine Ottumwa in 1947.
The city had changed dramatically since the flood of 1903. Automobiles were common, industry was important to the local economy and the railroad remained a major part of Ottumwa’s transportation network.
Yet despite all those changes, the Des Moines River still had the ability to overwhelm the community.
The river’s rise also demonstrated something that would become increasingly important in the decades ahead: flooding was not simply a nineteenth-century problem.
It was an ongoing part of life along the Des Moines River.
The 1965 Flood
Then came 1965.
Federal records show the Des Moines River reached 18.3 feet at Ottumwa on April 11, 1965.
While that crest was lower than the 1947 peak at Ottumwa, the 1965 flood was part of a much larger period of flooding across Iowa and the Midwest.
By this point, flood control was becoming a much bigger part of the conversation.
The federal government had already begun developing major flood-control projects on the Des Moines River. Lake Red Rock was completed in 1969, while Saylorville Lake was completed in the 1970s. Both reservoirs became important parts of the Des Moines River flood-control system.
So the story of Ottumwa’s floods isn’t simply a story about water.
It’s also a story about how the city, state and federal government gradually changed the way they prepared for that water.
From 1851 to 1965
Put the major floods side by side and you can see how much Ottumwa changed:
1851 — A young river community experienced a devastating flood that occurred before modern river-gauge records.
1903 — Ottumwa was a growing industrial and railroad city, and the flood became part of the earliest era of systematic river measurements.
1947 — The river climbed to 21.1 feet at Ottumwa, one of the city’s largest recorded crests.
1965 — Another major flood struck as Iowa was moving toward a new era of large-scale flood-control projects.
And the story didn’t stop there.
Ottumwa would experience major flooding again in 1993 and 2008. Today, the U.S. Army Corps of Engineers lists the record crest at the Ottumwa gauge as 22.15 feet, recorded July 12, 1993.
A River That Shaped Ottumwa
For generations, the Des Moines River has been both an asset and a threat to Ottumwa.
It helped shape the city’s history, transportation, industry and development. But the same river could also turn into a powerful force capable of shutting down roads, damaging property and forcing residents to protect what they had built.
The floods of 1903, 1947 and 1965 are reminders that the famous flood of 1851 was not an isolated event.
