Post Falls South Channel
Post Falls South Channel is a gravity dam located in Kootenai County, Idaho, built in 1906. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Post Falls South Channel
The primary purpose of Post Falls South Channel 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 Avista Corporation (private). It impounds the Spokane River near Greenacres Subdivision.
The dam stands 25 feet tall and stretches 127 feet across, creates a reservoir covering 48,000 acres, has a storage capacity of 225,000 acre-feet, and collects water from a drainage area of 3,784 square miles. Completed in 1906, 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 satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 08/17/2022.
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 Idaho 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 | Idaho |
| County | Kootenai |
| Nearest City | Greenacres Subdivision |
| River/Stream | Spokane River |
| Coordinates | 47.70370, -116.95569 |
Physical Characteristics
| Dam Type | Gravity |
| NID Height | 25 ft |
| Dam Height | 25 ft |
| Dam Length | 127 ft |
| Year Completed | 1906 (120 years old) |
Storage & Hydraulics
| NID Storage | 225,000 acre-ft |
| Normal Storage | 225,000 acre-ft |
| Surface Area | 48,000 acres |
| Drainage Area | 3,784 sq mi |
| Max Discharge | 3,600 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Hydroelectric |
| Owner | Avista Corporation |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 08/17/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | ID00497 |
| Federal ID | ID00220S002 |
| More Info | State Dam Safety Program |