Dam Report

John Orr dam

California, USA Tr Jackson Cr Hazard Low
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Tonight low
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Dam height
20ft
Hazard rating
Low
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John Orr -- None dam
John Orr None · Tr Jackson Cr
About this dam

John Orr

John Orr is a privately owned dam located in Ione, California, specifically on the Tr Jackson Cr river. Completed in 1959, this earth dam stands at 20 feet high with a hydraulic height of 16 feet and a length of 590 feet. Its primary purpose is for water supply, serving irrigation, recreation, and water supply needs in the area.

Managed by the California Department of Water Resources, John Orr is regulated, permitted, inspected, and enforced under state jurisdiction. With a storage capacity of 152 acre-feet and a drainage area of 0.85 square miles, this dam has a low hazard potential and is assessed to be in satisfactory condition as of September 2017. Despite its age, John Orr remains a vital infrastructure for water resource management in Amador County, California.

The dam's last inspection was conducted in October 2020, with a regular inspection frequency of once per year. While no emergency action plan (EAP) or risk assessment information is currently available, the dam's condition and hazard potential are continuously monitored to ensure the safety and reliability of its operations. As a key component in the water supply infrastructure of the region, John Orr plays a crucial role in sustaining water resources and adapting to the challenges of a changing climate.

StateNone
River / streamTr Jackson Cr
NID IDCA00615
Owner typePrivate
Primary purposeWater Supply
Dam typeEarth
Year built1959
Dam height20 ft
Dam length590 ft
Max storage152 AF
Surface area36.0 ac
Drainage area0.9 sq mi
Hazard potentialLow
ConditionSatisfactory
Last inspectionThu, 22 Oct 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 John Orr -- inflows here typically show up in storage 24-72 hours later.

Track John Orr 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 John Orr

Where does the data for John Orr 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.

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Premium feature

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Manage alerts in the Snoflo app

Custom alerts are configured in the iOS app -- favorite this dam, set a threshold, and you'll get a push the moment conditions cross.

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