Green Castle Dam
Green Castle Dam is an earth dam located in Marshall County, Iowa, built in 1954. It carries a Significant hazard potential classification and has a satisfactory condition assessment.
About Green Castle Dam
The primary purpose of Green Castle Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Marshall County Conservation Board (local government). It impounds the Tr- Brush Creek near Ferguson.
The dam stands 30 feet tall and stretches 650 feet across, creates a reservoir covering 17 acres, has a maximum storage capacity of 263 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1954, the structure is well into its service life at over 50 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 06/05/2020.
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Location
| State | Iowa |
| County | Marshall |
| Nearest City | Ferguson |
| River/Stream | Tr- Brush Creek |
| Coordinates | 41.93070, -92.86040 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 30 ft |
| Dam Height | 30 ft |
| Dam Length | 650 ft |
| Year Completed | 1954 (72 years old) |
Storage & Hydraulics
| NID Storage | 263 acre-ft |
| Max Storage | 263 acre-ft |
| Normal Storage | 150 acre-ft |
| Surface Area | 17 acres |
| Drainage Area | 0 sq mi |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | Marshall County Conservation Board |
| Owner Type | Local Government |
| Hazard Classification | Significant |
| Condition Assessment | Satisfactory |
| Last Inspection | 06/05/2020 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | IA02418 |
| Federal ID | IA02418 |
| More Info | State Dam Safety Program |