Cox Hollow Number One is an earth dam located in Iowa County, Wisconsin, built in 1961. It carries a Low hazard potential classification and has a fair condition assessment.
Dam profile
NID height · 37 ft37 ft tall and 625 ft long, taller than 83% 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 Cox Hollow Number One
The primary purpose of Cox Hollow Number One is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Wisconsin Department of Natural Resources (state). It impounds the Cox Hollow Creek.
The dam stands 37 feet tall and stretches 625 feet across, creates a reservoir covering 96 acres, has a maximum storage capacity of 1,040 acre-feet, and collects water from a drainage area of 7 square miles. Completed in 1961, the structure is well into its service life at over 50 years 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. Its condition is rated fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam. The most recent inspection on record was 11/09/2021.
At 37 feet, this dam is taller than 83% of dams nationwide.
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Location
| State | Wisconsin |
| County | Iowa |
| Nearest City | None |
| River/Stream | Cox Hollow Creek |
| Coordinates | 43.01350, -90.10528 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 37 ft |
| Dam Height | 37 ft |
| Dam Length | 625 ft |
| Year Completed | 1961 (65 years old) |
Storage & Hydraulics
| NID Storage | 1,040 acre-ft |
| Max Storage | 1,040 acre-ft |
| Normal Storage | 950 acre-ft |
| Surface Area | 96 acres |
| Drainage Area | 7 sq mi |
| Max Discharge | 860 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Recreation |
| Owner | Wisconsin Department of Natural Resources |
| Owner Type | State |
| Hazard Classification | Low |
| Condition Assessment | Fair |
| Last Inspection | 11/09/2021 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | WI00012 |
| Federal ID | WI00012 |
| More Info | State Dam Safety Program |