Annis dam
Annis
Annis is a privately owned irrigation dam located in Natrona, Wyoming, along Arkansas Creek. Completed in 1948, this earth dam stands at 25 feet high and has a storage capacity of 332 acre-feet. The dam serves the primary purpose of irrigation and has a spillway width of 12 feet. Despite its age, Annis is in fair condition with a low hazard potential, making it a crucial water resource for the surrounding area.
Managed by the Wyoming State Engineer's Office, Annis is regularly inspected with a frequency of 5 years to ensure its structural integrity. The dam has one slide gate for outlet control and a moderate risk assessment rating. With a drainage area of 0 square miles and a surface area of 26 acres, Annis plays a vital role in water management in the region, particularly in the city of Alcova. The dam's location in Congressional District 00, Wyoming, highlights its importance in water resource management at the federal level.
Overall, Annis represents a significant piece of infrastructure in Wyoming's water management system, providing crucial irrigation water and flood control along Arkansas Creek. With its stone core and soil foundation, the dam continues to serve its purpose effectively, meeting state regulatory requirements for inspection, permitting, and enforcement. As a key component of the Sacramento District's water infrastructure, Annis stands as a testament to the importance of sustainable water resource management 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 Annis -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Sweetwater River Near Alcova | 27 cfs | → |
| Medicine Bow R Ab Seminoe Reservoir | 38 cfs | → |
| N Platte Riv Ab Seminoe Reservoir | 1,640 cfs | → |
| Deer Creek In Canyon | 60 cfs | → |
| L Medicine Bow R At Boles Spring | 10 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Annis.
Boat launches
- Natrona County
- Gray Reef Road Natrona County
- Ledge Creek Boat Stopoff
- Trapper Route Road Natrona County
- Miles Landing Boat Ramp 2
- Miles Landing Boat Ramp 1
Campgrounds
- Bishops Point - Pathfinder Lake
- Diabase - Pathfinder Lake
- Sage - Pathfinder Lake
- Weiss - Pathfinder Lake
- Fremont Canyon - Alcova Reservoir
- Westside - Alcova Reservoir
Fishing spots
More reservoirs
Track Annis 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 Annis
Where does the data for Annis 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 Annis.