Morrison Dam dam
Morrison Dam
Morrison Dam, also known as Morrison Reservoir, is a historic gravity dam located in Malheur, Oregon, built in 1911 by the Bureau of Land Management for water supply purposes. With a height of 38 feet and a length of 425 feet, the dam holds a maximum storage capacity of 115 acre-feet and covers a surface area of 15.5 acres. It is situated on the South Fork of Little Willow Creek, contributing to the irrigation of the surrounding farm and ranch lands.
Despite its low hazard potential, Morrison Dam is in a poor condition according to the latest assessment in 2020, indicating a need for maintenance and repairs to ensure its continued functionality. The dam has not been modified in recent years and lacks certain emergency preparedness measures such as an Emergency Action Plan (EAP) and updated inundation maps. However, with a regular inspection frequency of 5 years, the Bureau of Land Management is actively monitoring the dam's integrity and safety to mitigate any potential risks.
As an integral water resource infrastructure in the region, Morrison Dam serves as a critical component of the local water supply system. With its historical significance and continued operational importance, efforts to maintain and enhance the dam's condition are essential for ensuring sustainable water management and climate resilience in the area.
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 Morrison Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Malheur River Below Nevada Dam Near Vale Or | 19 cfs | → |
| Snake River At Weiser Id | 19,100 cfs | → |
| Payette River Nr Payette Id | 7,870 cfs | → |
| Snake River At Nyssa Or | 10,000 cfs | → |
| Sand Run Gulch Nr Parma Id | 129 cfs | → |
| Owyhee River Below Owyhee Dam Or | 158 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Morrison Dam.
Boat launches
- Bully Creek Campground
- Malheur Reservoir
- Oasis Rv Park
- Spring Recreation Site
- Ontario State Park
- Nyssa River Park
Campgrounds
- Bully Creek Reservoir County Park
- Oasis
- Catfish Junction Rv Park
- Steck Park
- Spring
- Spring Recreation Site
Paddle runs
Track Morrison Dam 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 Morrison Dam
Where does the data for Morrison 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 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 Morrison Dam.