Orville dam
Orville
Orville, also known as Lake Orville, is a privately owned dam located in Angwin, California. Built in 1959, this earth dam stands at a height of 28 feet and serves primarily for water supply purposes, with irrigation and recreation also being supported. The dam has a storage capacity of 89 acre-feet and is situated on Angwin Creek in Napa County.
Managed by the California Department of Water Resources (DWR), the Orville dam is regulated, permitted, inspected, and enforced by state agencies to ensure its safety and functionality. Despite being rated with a high hazard potential, the dam's condition assessment deemed it as satisfactory during the last evaluation in September 2017. The dam's emergency action plan status, risk assessment, and inundation maps are not publicly disclosed, indicating a need for further information on its emergency preparedness.
With its strategic location and critical role in water supply, Orville dam presents both opportunities and challenges for water resource and climate enthusiasts. As a key infrastructure in the region, monitoring its maintenance and safety protocols is crucial to prevent potential hazards and ensure the continuous availability of water for various purposes in the 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 Orville -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Napa R Nr St Helena Ca | 15 cfs | → |
| Sonoma Creek A Kenwood Ca | 3 cfs | → |
| Putah C Nr Guenoc Ca | 51 cfs | → |
| Matanzas C A Santa Rosa Ca | 3 cfs | → |
| Maacama C Nr Kellogg Ca | 22 cfs | → |
| Santa Rosa C A Santa Rosa Ca | 20 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Orville.
⚓ Boat launches
- Chaparral Cove Napa County
- Knoxville Road 1601, Napa County
- Napa Valley Vine Trail, Napa
- Cuttings Wharf Road 3175-3337, Napa
- Cuttings Wharf Road 3270, Napa
- Ball Park Avenue 14775, Clearlake
⛺ Campgrounds
- Bothe - Napa Valley State Park
- Napa County Fairgrounds
- Chaparral Cove - Lake Berryessa - Usbr
- Camp Site 36-55
- Camp Site 1-35
- Camp Site 56-72
🎣 Fishing spots
More fishing →Track Orville 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 Orville
Where does the data for Orville 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 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 Orville.