Post Falls South Channel dam
Post Falls South Channel
Post Falls South Channel is a gravity dam located in Greenacres Subdivision, Idaho, on the Spokane River. Built in 1906, this hydroelectric dam stands at a height of 25 feet with a hydraulic height of 18 feet and a structural height of 25 feet. It serves multiple purposes including fish and wildlife pond, recreation, and hydroelectric power generation, with a normal storage capacity of 225,000 acre-feet.
With a hazard potential rated as high and a risk assessment indicating a very high risk level, the dam is under the regulatory oversight of the Federal Energy Regulatory Commission. It boasts a spillway width of 127 feet and features six vertical lift outlet gates. The dam's drainage area covers 3,784 square miles and its surface area spans 48,000 acres, making it a significant water resource structure in the region.
Despite its age, Post Falls South Channel remains a vital component of the water infrastructure in Kootenai County, Idaho. With its rich history and ongoing importance for both water management and energy production, this dam exemplifies the intersection of hydrology, engineering, and environmental stewardship in the face of changing climate conditions.
Dam data reference
Condition Assessment
- Satisfactory
- No existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
- Fair
- No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action.
- Poor
- A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency.
- Unsatisfactory
- A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
- Not Rated
- The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Hazard Potential Classification
- High
- Dams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
- Significant
- Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environmental damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
- Low
- Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
- Undetermined
- Dams for which a downstream hazard potential has not been designated or is not provided.
Plan around the weather
Same NOAA / yr.no feed Snoflo's iOS app uses. Watch the precipitation column on the meteogram -- rain on the basin upstream typically lifts inflow 24-72 hours later.
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
5-day forecast table
Every 3 hours, broken out across temperature, snow, rain, humidity, and wind. Each cell is colour-coded relative to the column min/max.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day temperature & precipitation
Daily temperatures, snow, and rain projected over the next two weeks.
Nearby streamflow gauges
USGS streamgauges around Post Falls South Channel -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Spokane River Nr Post Falls Id | 5,420 cfs | → |
| Spokane River Blw Blackwell Nr Coeur D Alene Id | 5,850 cfs | → |
| Coeur D Alene River Nr Harrison Id | 47 cfs | → |
| Little Spokane River At Dartford | 163 cfs | → |
| Spokane River At Spokane | 5,570 cfs | → |
| Hangman Creek At Spokane | 52 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Post Falls South Channel.
Boat launches
- Spokane River Centennial Trail Spokane County
- Blackwell Island Recreation Site
- Northeast Newman Lake Drive 12801, Newman Lake
- East Fernan Boat Ramp
- West Twin Lakes Road 9832, Kootenai County
- North Idaho Centennial Trail Coeur D'Alene
Campgrounds
- Liberty Lake Regional Park
- Mica Bay Boater Park
- Mokins Bay Campground
- Mokins Bay
- Mount Spokane State Park
- Beauty Creek Campground
Track Post Falls South Channel in the Snoflo app
Save this dam as a favorite and get the local NOAA / yr.no forecast plus regional flow context wherever you are.
About Post Falls South Channel
Where does the data for Post Falls South Channel come from?
Structural and regulatory data come from the U.S. Army Corps of Engineers' National Inventory of Dams (NID). Weather forecast comes from NOAA / yr.no -- the same feed Snoflo's iOS app uses.
How often is the report updated?
NID structural data refreshes annually as the Corps publishes updated assessments. The weather forecast refreshes throughout the day.
What does the High hazard rating mean?
The Corps of Engineers' hazard potential classification grades probable consequences if the dam fails: High = probable loss of human life; Significant = no probable loss of human life but possible economic loss / environmental damage; Low = no probable loss of human life, only minor economic / environmental losses. See the Dam Data Reference card above for the full definitions.
What's "% of normal"?
The current storage value compared to the historical average storage on this calendar day. 100% = right on average; values above 100% mean above-normal storage (wet year); values below mean below-normal (dry year or drought).
Can I get alerts when storage crosses a threshold?
Yes -- alerts are managed in the Snoflo iOS app. Favorite this dam, set a threshold, and you'll get a push the moment conditions cross.
Other water bodies near here
Snoflo-tracked reservoirs and dams within driving distance of Post Falls South Channel.