Coralville Milldam is a gravity dam located in Johnson County, Iowa, built in 1880. It carries a Low hazard potential classification.
Dam profile
NID height · 13 ft13 ft tall and 295 ft long. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic concrete gravity section and the water level is illustrative.
About Coralville Milldam
The primary purpose of Coralville Milldam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by City of Iowa City (local government). It impounds the Iowa River near Coralville.
The dam stands 13 feet tall and stretches 295 feet across, creates a reservoir covering 90 acres, has a maximum storage capacity of 758 acre-feet, and collects water from a drainage area of 3,271 square miles. Completed in 1880, the structure is over a century old.
This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected loss of life. The most recent inspection on record was 06/01/1999. That was over 27 years ago.
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Location
| State | Iowa |
| County | Johnson |
| Nearest City | Coralville |
| River/Stream | Iowa River |
| Coordinates | 41.67410, -91.56440 |
Physical Characteristics
| Dam Type | Gravity |
| NID Height | 13 ft |
| Dam Height | 13 ft |
| Dam Length | 295 ft |
| Year Completed | 1880 (146 years old) |
Storage & Hydraulics
| NID Storage | 758 acre-ft |
| Max Storage | 758 acre-ft |
| Normal Storage | 599 acre-ft |
| Surface Area | 90 acres |
| Drainage Area | 3,271 sq mi |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | City of Iowa City |
| Owner Type | Local Government |
| Hazard Classification | Low |
| Condition Assessment | Not assessed |
| Last Inspection | 06/01/1999 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | IA01275 |
| Federal ID | IA01275 |
| More Info | State Dam Safety Program |