Derby Diversion dam
Derby Diversion
The Derby Diversion, located in Washoe County, Nevada, along the Truckee River, is a concrete arch dam completed in 1904 primarily used for irrigation purposes. Managed by the Bureau of Reclamation, this Federal-owned structure stands at 31 feet high and has a storage capacity of 2,500 acre-feet. With a low hazard potential and a very high risk assessment rating, the dam has not been assessed for its condition, emergency action plan, or risk management measures.
Despite its age, the Derby Diversion continues to play a crucial role in water resource management in the region. As a key feature along the Truckee River, it provides irrigation water to support agricultural activities in the area. The dam's controlled spillway type and lack of outlet gates indicate a basic design intended for water diversion and storage purposes. Although the structure's condition assessment is not available, its historical significance and continued operation underscore its importance in the local water infrastructure.
Water resource and climate enthusiasts can appreciate the Derby Diversion as a historic and functional piece of infrastructure that contributes to the agricultural landscape of Washoe County, Nevada. As a Federal-owned dam managed by the Bureau of Reclamation, its presence along the Truckee River highlights the ongoing efforts to manage and allocate water resources in the region. While the dam's risk assessment is noted as very high, further evaluation and updates to its emergency action plan and risk management measures may be necessary to ensure its continued safe operation in the face of potential hazards.
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 Derby Diversion -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Truckee R Bl Derby Dam Nr Wadsworth | 710 cfs | → |
| Truckee River Nr Tracy | 1,280 cfs | → |
| Truckee Ca Nr Wadsworth | 372 cfs | → |
| Truckee R At Wadsworth | 681 cfs | → |
| Truckee R At Vista | 1,140 cfs | → |
| Truckee R Nr Nixon | 703 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Derby Diversion.
Boat launches
Campgrounds
- Lahontan Reservoir State Rec Area 1
- Silver Springs Beach - Lahotan State Park
- Lahontan Reservoir State Rec Area 2
- Fort Churchill State Park
- Dayton State Park
- Davis Creek
Fishing spots
Track Derby Diversion 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 Derby Diversion
Where does the data for Derby Diversion 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 Derby Diversion.