Lake John Annex dam
Lake John Annex
Lake John Annex is a state-owned recreation reservoir located in Jackson County, Colorado. Built in 1994 by the Colorado Division of Wildlife, this concrete dam on Lake Creek has a height of 7 feet and a storage capacity of 881 acre-feet. With a surface area of 221 acres and a drainage area of 10 square miles, the reservoir offers ample opportunities for outdoor activities such as fishing, boating, and wildlife viewing.
Despite its low hazard potential, Lake John Annex is rated as having a high risk level due to its risk assessment score of 2. While the condition of the dam is currently not rated, regular inspections are conducted every 6 years to ensure its safety and integrity. With its serene surroundings and recreational amenities, this reservoir serves as a popular destination for water enthusiasts and climate advocates alike, highlighting the importance of sustainable water resource management in the region.
Visitors to Lake John Annex can enjoy its tranquil waters and scenic landscapes while also appreciating the efforts made by state agencies to regulate, inspect, and enforce safety measures for the dam. As one of Colorado's recreational gems, this reservoir exemplifies the balance between human enjoyment and environmental stewardship, showcasing the vital role that water resources play in the overall health of our ecosystems and communities.
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 John Annex -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Michigan River At Walden | 37 cfs | → |
| North Platte River Near Northgate | 167 cfs | → |
| Encampment River Ab Hog Park Cr | 417 cfs | → |
| Illinois Creek Near Rand | 62 cfs | → |
| Fish Cr At Upper Sta Nr Steamboat Springs | 292 cfs | → |
| Yampa River At Steamboat Springs | 1,080 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Lake John Annex.
Boat launches
- Cowdrey Lake Rec Site Boat Ramp
- Cowdrey Lake Rec Site Boat Dock
- Teal Lake Boating Site
- Tombstone Nature Trail Routt County
Campgrounds
- Sheep Mountain Rec Area
- Cowdrey Lake Rec Site
- Big Creek Lakes
- Big Creek Lakes Campground
- North Sand Hills Rec Area
- North Sand Hills Campground
Fishing spots
Paddle runs
- Roaring Fork (West Section Line Sec 28 T9n, R82w); Red Canyon (Nw1/4 Sec 5, T8n, R82w) To East Section Line Sec 34, T9n, R82w
- Headwaters Of North, Middle And South Forks To Confluence Of South Fork With Encampment River
- South Sec Line, Sec 2, T11n, R80w To Co/Wy Stateline
- Northgate Canyon
- Big Creek
Track Lake John Annex 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 John Annex
Where does the data for Lake John Annex 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 Low 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 John Annex.