Woodbury County Roadgrade Dam 36-86-42 is an earth dam located in Woodbury County, Iowa, built in 1990. It carries a Significant hazard potential classification and has a satisfactory condition assessment.
Dam profile
NID height · 42 ft42 ft tall and 1,000 ft long, taller than 88% of U.S. dams with a recorded height. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic embankment section and the water level is illustrative.
About Woodbury County Roadgrade Dam 36-86-42
Woodbury County Roadgrade Dam 36-86-42 is a dam in Woodbury, Iowa. The dam is owned by Woodbury County Board of Supervisors (local government). It impounds the Tr- Maple River near Danbury.
The dam stands 42 feet tall and stretches 1,000 feet across, creates a reservoir covering 4 acres, has a maximum storage capacity of 540 acre-feet, and collects water from a drainage area of 1 square miles. Completed in 1990, the structure is 36 years old.
This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in loss of life. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. The most recent inspection on record was 06/23/2022.
At 42 feet, this dam is taller than 88% of dams nationwide.
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Location
| State | Iowa |
| County | Woodbury |
| Nearest City | Danbury |
| River/Stream | Tr- Maple River |
| Coordinates | 42.22280, -95.68670 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 42 ft |
| Dam Height | 42 ft |
| Dam Length | 1,000 ft |
| Year Completed | 1990 (36 years old) |
Storage & Hydraulics
| NID Storage | 540 acre-ft |
| Max Storage | 540 acre-ft |
| Normal Storage | 32 acre-ft |
| Surface Area | 4 acres |
| Drainage Area | 1 sq mi |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Other |
| Owner | Woodbury County Board of Supervisors |
| Owner Type | Local Government |
| Hazard Classification | Significant |
| Condition Assessment | Satisfactory |
| Last Inspection | 06/23/2022 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | IA02580 |
| Federal ID | IA02580 |
| More Info | State Dam Safety Program |