Mary No. 1 dam
Mary No. 1
Mary No. 1 is a privately owned earth dam located in Carbon County, Wyoming, along the North Fork Watkins Creek. Built in 1948 by designer Jame T Fletcher, this dam serves primarily for irrigation purposes, with a storage capacity of 140 acre-feet and a maximum discharge of 0. The dam stands at a height of 38 feet with a hydraulic height of 35 feet, stretching 450 feet in length. Despite its low hazard potential, the dam is currently assessed to be in poor condition, highlighting the need for maintenance and improvements.
With its uncontrolled spillway and one outlet valve, Mary No. 1 has a surface area of 10 acres and serves as a vital resource for fire protection, stock, and small fish pond irrigation in the region. The dam's condition assessment conducted in July 2021 revealed a moderate risk level (3), prompting the necessity for risk management measures to ensure the safety and functionality of the structure. Despite being state-regulated and permitted, the dam's poor condition underscores the importance of regular inspections and maintenance to mitigate potential risks and ensure its long-term reliability.
As water resource and climate enthusiasts, it is essential to monitor and support the upkeep of crucial infrastructure like Mary No. 1 to sustainably manage water resources and adapt to changing environmental conditions. By recognizing the significance of dams like Mary No. 1 in facilitating irrigation and other essential purposes, we can work towards enhancing their resilience and effectiveness in the face of evolving challenges posed by climate change and water scarcity. With proper maintenance and risk management measures, Mary No. 1 can continue to play a vital role in supporting agricultural activities and ecosystem health in the region.
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 Mary No. 1 -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Rock Creek Ab King Canyon Canal | 129 cfs | → |
| L Medicine Bow R At Boles Spring | 10 cfs | → |
| Pass Creek Near Elk Mountain | 149 cfs | → |
| Little Laramie River Near Filmore | 671 cfs | → |
| North Brush Creek Near Saratoga | 57 cfs | → |
| Laramie River Near Bosler | 1,950 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Mary No. 1.
Boat launches
- Carbon County
- East Allen Lake Boat Ramp
- East Allen Lake Boat Launch
- Herrick Lane Albany County
- Wheatland Reservoir #3 Boat Ramp
- Palmer Canyon Road Albany County
Campgrounds
- Bow River Campground
- Bow River
- Bow River Ranger Station
- Deep Creek
- East Allen Lake Public Access - Wgf
- Brooklyn Lake Campground
Fishing spots
Paddle runs
More reservoirs
Track Mary No. 1 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 Mary No. 1
Where does the data for Mary No. 1 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 Mary No. 1.