Jackson #1 dam
Jackson #1
Jackson #1 is a significant earth dam located in Twin Bridges, Montana, along the Wisconsin Creek. Built in 1924 for irrigation purposes, this dam stands at a height of 19 feet and has a storage capacity of 38 acre-feet. It is regulated by the Montana Department of Natural Resources and Conservation, with state jurisdiction, permitting, inspection, and enforcement in place to ensure its safety and compliance with regulations.
With a controlled spillway and slide gate outlet gates, Jackson #1 has been deemed to have a significant hazard potential and a very high risk assessment rating. Despite its age, the dam's condition has not been formally assessed, but it remains operational and serves its intended purpose effectively. The dam has not undergone any modifications in recent years and is not owned or funded by any federal agencies, making it a unique and locally managed water resource structure in the area.
For water resource and climate enthusiasts, Jackson #1 offers a fascinating glimpse into the history and engineering of irrigation infrastructure in Montana. Its location in the beautiful Madison County, surrounded by natural landscapes, adds to its appeal as a point of interest for those interested in the management and conservation of water resources. As one of the older dams in the state, Jackson #1 serves as a reminder of the importance of maintaining and monitoring aging infrastructure to ensure the safety and sustainability of water systems for future generations.
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 Jackson #1 -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Jefferson River Near Twin Bridges Mt | 2,830 cfs | → |
| Ruby River Near Twin Bridges Mt | 55 cfs | → |
| Willow Creek Near Harrison Mt | 10 cfs | → |
| Beaverhead River Near Twin Bridges Mt | 62 cfs | → |
| Madison River Bl Ennis Lake Nr Mcallister Mt | 1,400 cfs | → |
| Ruby River Bl Reservoir Nr Alder Mt | 421 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Jackson #1.
Boat launches
- Mt 359 Jefferson County
- Us 287 Gallatin County
- Trail Creek Day Use
- Power House Boat Launch
- Fall Creek Day Use
- Montana Highway 84 Madison County
Campgrounds
Fishing spots
Paddle runs
- Beaverhead Boundary Sec. 22, T4s, R4w To Upper Branham Lake, Sec. 5, T4s, R3w
- Madison River
- Beartrap Canyon - Madison Dam To Route 84
More reservoirs
Track Jackson #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 Jackson #1
Where does the data for Jackson #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 Significant 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 Jackson #1.