Sylvan
Sylvan is a gravity dam located in Cass County, Minnesota, built in 1913. It carries a High hazard potential classification and has a fair condition assessment.
About Sylvan
The primary purpose of Sylvan is hydroelectric. The dam generates hydroelectric power by channeling water through turbines, converting the energy of flowing water into electricity. The dam is owned by Allete, Inc. (private). It impounds the Crow Wing near Little Falls.
The dam stands 35 feet tall and stretches 1,154 feet across, creates a reservoir covering 1,280 acres, has a storage capacity of 9,216 acre-feet, and collects water from a drainage area of 3,575 square miles. Completed in 1913, the structure is over a century old.
This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. 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 09/20/2021.
At 35 feet, this dam is taller than 82% of dams nationwide.
Living Downstream
If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Minnesota dam safety program can provide more specific information about emergency planning for this structure.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Minnesota |
| County | Cass |
| Nearest City | Little Falls |
| River/Stream | Crow Wing |
| Coordinates | 46.30490, -94.37800 |
Physical Characteristics
| Dam Type | Gravity |
| NID Height | 35 ft |
| Dam Height | 35 ft |
| Dam Length | 1,154 ft |
| Year Completed | 1913 (113 years old) |
Storage & Hydraulics
| NID Storage | 9,216 acre-ft |
| Normal Storage | 9,216 acre-ft |
| Surface Area | 1,280 acres |
| Drainage Area | 3,575 sq mi |
| Max Discharge | 22,000 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Hydroelectric |
| Owner | Allete, Inc. |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Fair |
| Last Inspection | 09/20/2021 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MN00601 |
| Federal ID | MN00601 |
| More Info | State Dam Safety Program |