Guernsey dam
Guernsey
Guernsey, located in Platte, Wyoming, is a federal-owned dam along the North Platte River with a primary purpose of hydroelectric power generation and irrigation. Built in 1926, this earth dam stands at 135 feet high and has a storage capacity of 45,612 acre-feet. With a surface area of 2,380 acres and a drainage area of 15,008 square miles, Guernsey plays a crucial role in water resource management in the region.
Managed by the Bureau of Reclamation, Guernsey has undergone structural modifications in 1984 and 2016 to ensure its safety and functionality. The dam is equipped with a controlled spillway and tainter gates for water release, with a high hazard potential due to its location and design. Despite its age, the condition assessment of Guernsey is currently not available, highlighting the need for ongoing monitoring and maintenance to safeguard against potential risks and ensure its continued operation for both hydroelectric power generation and irrigation purposes.
With Liz Cheney (R) as the congressional representative for the area, Guernsey remains a vital component of the water infrastructure in Wyoming. As a key player in regulating and inspecting the dam, the Bureau of Reclamation is responsible for its operations and ensuring compliance with state regulatory agencies. Water resource and climate enthusiasts can appreciate the engineering feats and environmental impact of Guernsey, a historic structure that continues to serve the community while facing challenges of aging infrastructure and evolving safety standards in the face of climate change.
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 Guernsey -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| North Platte River Below Whalen Diversion Dam | · | → |
| Laramie River Near Fort Laramie | 41 cfs | → |
| North Platte River Below Glendo Reservoir | 5,710 cfs | → |
| North Platte River At Orin | 392 cfs | → |
| Sybille Creek Ab Canal No. 3 | 93 cfs | → |
| Sybille Creek Ab Mule Creek | 143 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Guernsey.
Campgrounds
- Guernsey State Park
- Larson Park
- Grayrocks Reservoir Public Access - Wgf
- Glendo State Park
- Lewis Park
- Lewis Park Campground
Fishing spots
- Guernsey Reservoir
- Grayrocks Reservoir
- Glendo Reservoir
- Wheatland Reservoir #1
- Rock Lake
- Toltec Reservoir
Track Guernsey 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 Guernsey
Where does the data for Guernsey 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 Guernsey.