Harriet Lake dam
Harriet Lake
Harriet Lake, located in Clackamas County, Oregon, is a privately owned reservoir primarily used for hydroelectric power generation. Constructed in 1923, this arch dam stands at 68 feet tall and spans 186 feet in length, with a storage capacity of 400 acre-feet. The lake covers an area of 22 acres and is fed by the Oak Grove River, with a maximum discharge rate of 11,200 cubic feet per second.
Despite its age, Harriet Lake boasts a low hazard potential and a moderate risk assessment rating. While the condition assessment is not currently available, the dam is inspected annually by the Federal Energy Regulatory Commission to ensure its safety and compliance with regulations. The spillway, with a width of 134 feet, is uncontrolled, adding to the recreational opportunities and potential for downstream water management.
Although privately owned, Harriet Lake offers not only hydroelectric power but also recreational opportunities for visitors. With its scenic location and historical significance, this dam serves as a vital resource in the region's water management infrastructure while providing a picturesque backdrop for those who visit.
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 Harriet Lake -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Oak Grove Fork Above Powerplant Intake | 296 cfs | → |
| Oak Grove Fork At Ripplebrook Campground | 111 cfs | → |
| Clackamas River Above Three Lynx Creek | 931 cfs | → |
| Oak Grove Fork Near Government Camp | 71 cfs | → |
| Bull Creek Near Wilhoit | 0 cfs | → |
| Nate Creek Tributary Near Colton | 0 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Harriet Lake.
Boat launches
- Harriet Lake
- Sandstone Bridge Boat Access Day Use
- Hoodview Campground
- Clackamas Highway Clackamas County
- Hole In The Wall Boat Access Day Site
- Gone Creek Campground
Campgrounds
- Lake Harriet Campground/Day Use
- Shellrock Creek Campground
- Hideaway Lake Campground
- Ripplebrook Campground
- Rainbow Campground
- Riverford Campground
Paddle runs
- Timothy Lake Dam To Slackwater Of Harriet Lake
- North Fork Clackamas River
- Salmon River Canyon (Split Falls To Road Access)
- Welches Run
- Headwaters To North Section Line Of Sec 17, T4s, R5e
- North Section Line Of Sec 17, T4s, R5e To Slackwater North Fork Reservoir
More reservoirs
Track Harriet Lake 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 Harriet Lake
Where does the data for Harriet Lake 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 Low 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 Harriet Lake.