Lake Ann dam
Lake Ann
Lake Ann, also known as Dinkle Lake, is a private reservoir located in Pitkin County, Colorado, near the city of El Jebel. The dam, completed in 1912 and designed by BOND Engineering, stands at a height of 40 feet and serves primarily for irrigation purposes. With a storage capacity of 562 acre-feet, the reservoir covers an area of 20 acres and is fed by the West Sopris Creek.
Despite its age, Lake Ann has been regularly inspected and maintained by the Colorado Department of Water Resources (DWR), with a fair condition assessment as of July 2020. The dam's spillway, an uncontrolled type with a width of 40 feet, has a high hazard potential but is considered to have a moderate risk level. The reservoir's emergency action plan (EAP) was last revised in December 2015, and the facility is equipped with a slide (sluice gate) outlet gate for water release.
Lake Ann offers not only essential irrigation functions but also recreational opportunities for the local community. With its picturesque location and historical significance, this reservoir serves as a vital water resource in the region while maintaining a balance between water management and environmental preservation.
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 Lake Ann -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Roaring Fork River Near Emma | 372 cfs | → |
| Crystal River Ab Avalanche C | 712 cfs | → |
| Fryingpan River Near Ruedi | 117 cfs | → |
| Hunter Creek Near Aspen | 8 cfs | → |
| Roaring Fork River Near Aspen | 130 cfs | → |
| Roaring Fork River At Glenwood Springs | 1,060 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Lake Ann.
Boat launches
- Wingo Boat Ramp
- Grizzly Creek Garfield County
- South Canyon Boat Ramp
- I 70 Garfield County
- Dotsero Landing Boat Ramp
- Community Boat Ramp
Campgrounds
- Upper Prince Creek Campground
- Lower Prince Creek Campground
- Avalanche Campground
- Avalanche
- Thompson Creek Camp
- Redstone
Fishing spots
- Christine Lake
- Fryingpan River
- Beaver Lake Swa (Marble)
- Ruedi Reservoir
- Emerald Lake (Crested Butte)
- Sylvan Lake
Track Lake Ann 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 Lake Ann
Where does the data for Lake Ann 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 Lake Ann.