Nine Mile dam
Nine Mile
Nine Mile is a captivating hydroelectric facility located in Spokane, Washington, along the picturesque Spokane River. This privately owned dam, completed in 1908, boasts a gravity design with a height of 58 feet and a hydraulic height of 68 feet. With a storage capacity of 4,600 acre-feet and a surface area of 440 acres, Nine Mile serves multiple purposes including hydroelectric power generation, fish and wildlife conservation, and recreation.
Managed by the Federal Energy Regulatory Commission, Nine Mile is a significant contributor to the region's energy production, with a maximum discharge capacity of 60,000 cubic feet per second. The dam's controlled spillway, with a width of 225 feet, ensures efficient water management during periods of high flow. However, the dam is classified as having a high hazard potential and a very high risk assessment due to its age and condition, highlighting the importance of regular inspections and emergency preparedness.
As a key player in the region's water resource management, Nine Mile is not only a source of renewable energy but also a vital contributor to the local ecosystem and recreational activities. Its historical significance and engineering marvel make it a must-visit destination for water resource and climate enthusiasts looking to witness firsthand the intersection of human ingenuity and natural beauty.
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 Nine Mile -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Spokane River Below Nine Mile Dam At Spokane | 6,100 cfs | → |
| Little Spokane River Near Dartford | 408 cfs | → |
| Little Spokane River At Dartford | 163 cfs | → |
| Spokane River At Spokane | 5,570 cfs | → |
| Hangman Creek At Spokane | 52 cfs | → |
| Chamokane Creek Below Falls Near Long Lake | 27 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Nine Mile.
Boat launches
- North Aubrey L White Parkway Spokane
- South Gorge Trail Spokane
- West Fancher Road, Medical Lake
- Northeast Newman Lake Drive 12801, Newman Lake
- Spokane River Centennial Trail Spokane County
- Viewpoint Road 61, Newport
Track Nine Mile 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 Nine Mile
Where does the data for Nine Mile 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 Nine Mile.