Dutch Flat Afterbay dam
Dutch Flat Afterbay
Dutch Flat Afterbay, located in Nevada County, California, is a rockfill dam completed in 1965 with a primary purpose of irrigation. With a height of 165 feet and a storage capacity of 2037 acre-feet, this dam plays a crucial role in providing water for agricultural purposes in the region. The dam is regulated by the Federal Energy Regulatory Commission and inspected by the same agency to ensure its safe operation.
The Dutch Flat Afterbay dam has a low hazard potential and a moderate risk assessment, indicating that it is well-maintained and poses minimal threat to surrounding areas. The spillway of the dam is uncontrolled with a width of 100 feet, allowing for the controlled release of excess water during periods of high flow. The dam is also equipped with emergency action plans to ensure preparedness in case of any unforeseen events.
Overall, Dutch Flat Afterbay serves as a vital water resource infrastructure in the region, supporting irrigation, hydroelectric power generation, and water supply needs. Its design by Ebasco Services, Inc. and regulation by state and federal agencies demonstrate the commitment to maintaining the safety and reliability of this important water management structure for the benefit of 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 Dutch Flat Afterbay -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Nf American R A North Fork Dam Ca | 773 cfs | → |
| N Yuba R Bl Goodyears Bar Ca | 663 cfs | → |
| Deer C Nr Smartville Ca | 59 cfs | → |
| Pilot C Bl Mutton Canyon Nr Georgetown Ca | 2 cfs | → |
| Pilot C Ab Stumpy Meadows Res Ca | 3 cfs | → |
| Donner C A Donner Lk Nr Truckee Ca | 10 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Dutch Flat Afterbay .
Boat launches
- Iowa Hill Road Placer County
- Lake Spaulding Road 10260, Nevada City
- Fuller Lake Boating Site
- Oxbow Raft Put-In Site
- Mosquito Ridge Rd, California
- Meadow Lake Road Nevada County
Campgrounds
Fishing spots
Paddle runs
- Chamberlain Falls (Iowa Hill To Yankee Jim)
- One-Half Mile West Of Confluence With Fall Creek To Confluence With Jefferson Creek
- Langs Crossing Bridge To One-Half Mile West Of Confluence With Fall Creek (Boundary Of Nf And Private Land)
- Yankee Jim Road To Ponderosa Way (Shirttail)
- Generation And Giant Gaps (Tadpole To Colfax-Iowa Hill Road)
- Tunnel Run (Ralston Powerhouse To Greenwood)
Track Dutch Flat Afterbay 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 Dutch Flat Afterbay
Where does the data for Dutch Flat Afterbay 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 Dutch Flat Afterbay .