Gibson dam
Gibson
Gibson, also known as Beaver Creek or Gibson Reservoir, is a federal-owned structure located in Simms, Montana. It was completed in 1928 by the Bureau of Reclamation for the primary purpose of irrigation on the North Fork Sun River. This concrete dam stands at a height of 199 feet and has a storage capacity of 121,981 acre-feet, with a normal storage level of 99,059 acre-feet.
The reservoir covers a surface area of 1,420 acres and has a drainage area of 575 square miles. With a maximum discharge capacity of 50,000 cubic feet per second, Gibson has a controlled spillway with a width of 204 feet to manage water flow. The dam's hazard potential is classified as high, and it underwent modifications in 1981 for both hydraulic and structural enhancements.
Although the condition assessment of Gibson is currently not available, the risk assessment for the dam is rated as very high. Emergency action plans have been prepared, with the last revision in November 2014. With its significant role in irrigation and water resource management in the region, Gibson remains a key infrastructure for water supply and climate resilience efforts in Montana.
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 Gibson -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Sun River Bl Diversion Dam Nr Augusta Mt | 641 cfs | → |
| South Fork Sun River Near Augusta Mt | 685 cfs | → |
| North Fork Sun River Near Augusta Mt | 564 cfs | → |
| Sun River Bl Willow Cr Nr Augusta Mt | 561 cfs | → |
| Teton River Bl South Fork Nr Choteau Mt | 167 cfs | → |
| Sun River At Simms Mt | 588 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Gibson.
Campgrounds
Fishing spots
- Sun River Slope Canal
- Dry Creek-Krezelok Reservoir
- Big Salmon Creek
- Big Salmon Lake
- Davis Lake
- Duck Creek
Paddle runs
- Wilderness Boundary To South Fork Sun River, Sec. 26, T22n, R10w
- Headwaters, Sec. 4, T18n, R10w To North Fork Sun River, Sec. 26, T22n, R10w
- Fool Creek, Sec. 24, T25n, R11w To Wilderness Boundary
- Headwaters, Sec. 15, T18n, R10w To Straight Creek, Sec. 25, T19n, R10w
- Dobrota Headwaters, Sec. 23, T18n, R10w To Mainstem, Sec. 31, T18n, R9w
- Cooney Cr Headwaters, Sec. 17, T19n, R9w To Mainstem, Sec. 1, T17n, R10w
Track Gibson 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 Gibson
Where does the data for Gibson 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 Gibson.