Willow Lake Dam
Willow Lake Dam is an earth dam located in Harrison County, Iowa, built in 1976. It carries a Low hazard potential classification.
About Willow Lake Dam
The primary purpose of Willow Lake Dam is debris control. The dam is designed to catch sediment, rocks, and debris carried by flowing water — particularly important in areas prone to mudslides or heavy erosion. The dam is owned by Harrison County Conservation Board (local government). It impounds the Tr-willow Creek near Missouri Valley.
The dam stands 31 feet tall and stretches 390 feet across, creates a reservoir covering 19 acres, has a maximum storage capacity of 44 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1976, the structure is 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.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Iowa |
| County | Harrison |
| Nearest City | Missouri Valley |
| River/Stream | Tr-willow Creek |
| Coordinates | 41.77510, -95.78470 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 31 ft |
| Dam Height | 31 ft |
| Dam Length | 390 ft |
| Year Completed | 1976 (50 years old) |
Storage & Hydraulics
| NID Storage | 44 acre-ft |
| Max Storage | 44 acre-ft |
| Normal Storage | 21 acre-ft |
| Surface Area | 19 acres |
| Drainage Area | 0 sq mi |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Debris Control |
| Owner | Harrison County Conservation Board |
| Owner Type | Local Government |
| Hazard Classification | Low |
| Condition Assessment | Not Rated |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | IA01566 |
| Federal ID | IA01566 |
| More Info | State Dam Safety Program |