Eleven Mile Canyon dam
Eleven Mile Canyon
Eleven Mile Canyon is a concrete dam located in Park County, Colorado, serving as a vital water supply source in the region. Completed in 1932, this dam stands at a height of 128 feet, with a hydraulic height of 126 feet and a structural height of 151 feet. It has a storage capacity of 128,000 acre-feet and a normal storage level of 97,800 acre-feet, covering a surface area of 3,500 acres. The dam is situated on the South Platte River, managed by the Department of Water Resources (DWR) in Colorado.
With a high hazard potential but a satisfactory condition assessment as of June 2020, Eleven Mile Canyon is a crucial infrastructure for water resource management in the area. The dam's spillway is uncontrolled, with a width of 75 feet, and it has a maximum discharge capacity of 3,500 cubic feet per second. The risk assessment for the dam is moderate, indicating the need for ongoing monitoring and maintenance to ensure its safety and reliability for the community it serves. The dam is regulated, permitted, inspected, and enforced by the state of Colorado, demonstrating a commitment to upholding stringent safety standards and protocols.
Eleven Mile Canyon offers a glimpse into the intersection of water resource management and climate adaptation efforts in Colorado. As a primary water supply structure, it plays a vital role in ensuring water security for the region. With its historical significance and ongoing monitoring and maintenance efforts, the dam stands as a testament to the importance of sustainable water infrastructure in the face of evolving climate challenges.
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 Eleven Mile Canyon -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| South Platte River Near Lake George | 228 cfs | → |
| S Platte R Ab 11-Mile Canyon Re | 264 cfs | → |
| South Platte River Above Cheesman Lake | 263 cfs | → |
| Fourmile Creek Below Cripple Creek Near Victor | 5 cfs | → |
| West Cr. Abv Shrewsbury Gulch Nr Westcreek Co | 1 cfs | → |
| South Platte River Below Cheesman Lake | 138 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Eleven Mile Canyon.
Boat launches
- Forest Road 96.I Park County
- Thirtynine Mile Road Park County
- Tarryall Road Park County
- Skagway Road Teller County
- Ahra - Parkdale Rec Site
- Ahra - Spikebuck Rec Site
Campgrounds
Fishing spots
- Elevenmile Canyon Reservoir
- Eleven Mile Reservoir
- Spinney Mountain Reservoir
- North Catamount Reservoir
- Cheesman Reservoir
- South Catamount Reservoir
Track Eleven Mile Canyon 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 Eleven Mile Canyon
Where does the data for Eleven Mile Canyon 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 Eleven Mile Canyon.