Big Rock Detention Dam
Low HazardUnsatisfactory ConditionEmergency Action Plan: Not Required
Location
| State | Montana |
| County | Valley |
| Nearest City | NASHUA |
| River/Stream | WILLOW CK./MILK RIVER |
| Coordinates | 48.08686, -106.95780 |
Physical Characteristics
| Dam Type | Gravity |
| NID Height | 13 ft |
| Dam Length | 1,793 ft |
| Year Completed | 1961 (65 years old) |
Storage & Hydraulics
| NID Storage | 265 acre-ft |
| Max Storage | 265 acre-ft |
| Surface Area | 62 acres |
| Drainage Area | 0 sq mi |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | DOI BLM |
| Owner Type | Federal |
| Hazard Classification | Low |
| Condition Assessment | Unsatisfactory |
| Last Inspection | 11/02/2019 |
| Emergency Action Plan | Not Required |