Cottonwood Creek Upper dam
Cottonwood Creek Upper
Cottonwood Creek Upper, also known as Cottonwood Detention Dam #1, is a key water resource infrastructure owned by the local government in Boise, Idaho. This structure plays a vital role in flood risk reduction, serving as a barrier to protect the surrounding areas from potential flooding. Completed in 1961, the dam stands at a height of 18.1 feet and has a hydraulic height of 13.1 feet, with a length of 840 feet and a storage capacity of 17 acre-feet.
Situated on Cottonwood Creek in the Boise River watershed, this earth dam with stone core is regulated by the Idaho Department of Water Resources and undergoes regular state inspection and enforcement to ensure its structural integrity. With a significant hazard potential and fair condition assessment, the dam's risk management measures are crucial to maintaining its functionality in the face of moderate risk levels. The last inspection in September 2018 revealed no major issues, but the structure is monitored closely to prevent any potential emergencies and ensure the safety of the surrounding community.
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 Cottonwood Creek Upper -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Cottonwood Creek Bel Fivemile Cr Nr Boise Id | 1 cfs | → |
| Boise River At Glenwood Bridge Nr Boise Id | 1,760 cfs | → |
| Boise River South Channel At Eagle Id | 1,120 cfs | → |
| Dry Creek Nr Eagle Id | 0 cfs | → |
| Eagle Drain At Eagle | 44 cfs | → |
| Mores Creek Ab Robie Creek Nr Arrowrock Dam Id | 227 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Cottonwood Creek Upper.
Boat launches
- Robie Creek Road Boise County
- Parnell Recreation Site
- Upper Embankment Road Canyon County
- Beehive Bend
- Look Lane 21723, Canyon County
Campgrounds
- Gowen Field Military
- Shafer Butte Cg And Group Sites - Reserve - Tent
- Macks Creek
- Shafer Butte
- Arrowrock Reservoir Dispersed
- Indian Creek Reservoir
Paddle runs
- Boise Nf Boundary To Confluence With Willow Creek
- Confluence With Granite Creek To Confluence With Pine Creek
- Trail Creek To Confluence With Crank Creek
- Confluence With Rabbit Creek To Confluence With Middle Fork Boise River
- Mennecke Creek To Confluence With Trail Creek
- Boise Nf Boundary (1 Mile East Of Banks) To Boise Nf Boundary (1 Mile South Of Banks)
Track Cottonwood Creek Upper 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 Cottonwood Creek Upper
Where does the data for Cottonwood Creek Upper 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 Cottonwood Creek Upper.