Ish #3 (Main Dam)
Colorado — Larimer County — BIG THOMPSON RIVER-OS
Location
| State | Colorado |
| County | Larimer |
| River | BIG THOMPSON RIVER-OS |
| Coordinates | 40.26309, -105.09555 |
Physical Characteristics
| NID Height | 48 ft |
| Dam Height | 42 ft |
| Dam Length | 6,700 ft |
| NID Storage | 9,065 acre-ft |
| Max Storage | 9,065 acre-ft |
| Surface Area | 314 acres |
Safety Classification
| Hazard Potential | High |
| Condition Assessment | Satisfactory |
| EAP Status | Yes |
| Last Inspection | July 20, 2022 |
| Inspection Frequency | 1 |
Dam Information
| Year Completed | 1905 |
| Primary Purpose | Irrigation |
| Dam Type | Earth |
| Owner Type | Private |
| Owner | THE ISH RESERVOIR COMPANY |
| Other Name | Boulder-Larimer, Old Ish, New Ish |
Location Map
About This Dam Record
Dam safety data is maintained by the Army Corps of Engineers National Inventory of Dams (NID). High-hazard dams are those where failure could cause loss of life or major property damage downstream.