Denver's creeks can flood, and dams upstream hold them back

Denver grew up where Cherry Creek meets the South Platte, and the water that built the city has also flooded it.

Cherry Creek flooded Denver repeatedly in the city’s early decades. To hold it back, the U.S. Army Corps of Engineers built Cherry Creek Dam upstream, finishing it in 1950. The South Platte was a different story: in June 1965 it flooded badly, taking lives and wrecking buildings along the river. After that flood, the Corps built Chatfield Dam on the South Platte above the city, completing it in 1975. Together, these dams greatly reduced the danger.

But flood risk did not vanish. Low ground near the rivers and creeks can still flood in a big storm, and that is exactly where some of the oldest and lowest neighborhoods sit. If you are buying near the South Platte, Cherry Creek, or one of the smaller creeks, it is worth knowing whether the property is in a mapped floodplain.

Why care: floodplain status can affect insurance and what you can build, and it is simply good to know before water rises.

To check a specific address, look at FEMA flood maps, and for the dams see the Army Corps of Engineers’ pages on its Tri-Lakes projects.