Dam Report

Bowman Arch dam

California, USA Canyon Creek Hazard High
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Dam height
105ft
Hazard rating
High
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Bowman Arch                                                       -- None dam
Bowman Arch None · Canyon Creek
About this dam

Bowman Arch

Bowman Arch, located in California's Nevada County, is a stunning arch dam constructed in 1927 for irrigation purposes. With a height of 105 feet and a storage capacity of 68,500 acre-feet, this dam plays a crucial role in water management in the region. The dam also serves multiple purposes including hydroelectric power generation, recreation, and water supply, highlighting its importance in the local ecosystem.

Managed by the Federal Energy Regulatory Commission, Bowman Arch has a spillway width of 114 feet and a maximum discharge of 19,500 cubic feet per second. The dam's hazard potential is classified as high, emphasizing the need for regular inspections and maintenance to ensure its safety and integrity. With a history dating back almost a century, Bowman Arch stands as a testament to engineering excellence and the importance of water resource management in mitigating climate challenges and supporting sustainable development in the region.

As a multi-purpose structure with a very high risk assessment rating, Bowman Arch embodies the intricate balance between water resource utilization and environmental conservation. Its association with controlled spillways and radial outlet gates underscores the technological sophistication of the dam. With a primary focus on irrigation, the dam continues to play a vital role in supporting agriculture and water supply needs in the area. For water resource and climate enthusiasts, Bowman Arch serves as a remarkable example of sustainable infrastructure that adapts to changing environmental conditions while meeting the diverse needs of the community.

StateNone
River / streamCanyon Creek
NID IDCA00245
Owner typePublic Utility
Primary purposeIrrigation
Dam typeArch
Year built1927
Dam height105 ft
Dam length567 ft
Max storage68,500 AF
Normal storage63,700 AF
Surface area810.0 ac
Drainage area29.0 sq mi
Hazard potentialHigh
ConditionNot Available
Last inspectionWed, 30 Sep 2020 00:00:00 GMT

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.
Detailed forecast

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.

Hourly detail

Next 5 days, hour by hour

Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.

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Deep dive

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.

TimeConditionTemp (°F)Snow (in)Rain (in)Humidity (%)Wind (mps)Wind dir
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Long-term outlook

15-day temperature & precipitation

Daily temperatures, snow, and rain projected over the next two weeks.

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Regional inflow

Nearby streamflow gauges

USGS streamgauges around Bowman Arch -- inflows here typically show up in storage 24-72 hours later.

Track Bowman Arch 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.

FAQ

About Bowman Arch

Where does the data for Bowman Arch 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.