Howard A. Hanson Dam dam
Howard A. Hanson Dam
Howard A. Hanson Dam, located in Auburn, Washington, is a rockfill dam primarily designed for flood risk reduction along the Green River. Completed in 1962 by the US Army Corps of Engineers (USACE), the dam has a hydraulic height of 220 feet and a structural height of 235 feet, with a maximum storage capacity of 136,700 acre-feet. While the dam plays a crucial role in reducing flood risks, extreme rainfall events could still necessitate controlled releases through the outlet tunnel or spillway to prevent overtopping and potential failure.
USACE has implemented numerous risk management measures to ensure the dam's safety and reduce risks to life safety and property. This includes regular inspections, monitoring instrumentation, and maintenance activities to address any potential concerns. The agency also collaborates with local emergency managers to update the Emergency Action Plan annually, conducts emergency exercises, and hosts stakeholder meetings to keep the community informed. Despite the low likelihood of dam failure scenarios, USACE remains committed to safeguarding the dam and mitigating potential risks to downstream communities in Auburn, Kent, and beyond.
Overall, Howard A. Hanson Dam remains a vital infrastructure for flood risk reduction in the region, with USACE's ongoing efforts to maintain the dam's integrity and ensure its resilience in the face of extreme weather events. Through continuous monitoring, maintenance, and collaboration with local authorities, the dam serves as a critical asset in protecting communities from potential flooding disasters.
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 Howard A. Hanson Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Green River Below Howard A Hanson Dam | 378 cfs | → |
| Green River At Purification Plant Near Palmer | 256 cfs | → |
| Boulder Creek Near Cedar Falls | 0 cfs | → |
| Rex River Near Cedar Falls | 11 cfs | → |
| Taylor Creek Near Selleck | 28 cfs | → |
| Cedar River At Cedar Falls | 91 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Howard A. Hanson Dam.
Boat launches
See all →
Campgrounds
See all →
Fishing spots
See all →
River runs
See all →
About Howard A. Hanson Dam
Where does the data for Howard A. Hanson Dam 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 below 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.
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.