Dam Report

Lower Diversion dam

Idaho, USA Snake River Hazard Low
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Tonight low
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Dam height
14ft
Hazard rating
Low
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Lower Diversion -- None dam
Lower Diversion None · Snake River
About this dam

Lower Diversion

Lower Diversion, located in Shelley, Idaho, is a crucial hydroelectric facility along the Snake River with a primary purpose of generating clean energy. Constructed in 1982, this gravity dam stands at a height of 14 feet and has a storage capacity of 1200 acre-feet, serving as a reliable source of power and recreation for the local community. The dam has a controlled spillway, with a width of 930 feet, to manage water flow and ensure safety during periods of high discharge.

Owned and regulated by the local government and the Federal Energy Regulatory Commission, Lower Diversion undergoes regular inspections to maintain its low hazard potential and ensure its structural integrity. With a drainage area of 9800 square miles and a maximum discharge capacity of 75,000 cubic feet per second, the dam plays a crucial role in managing water resources and mitigating flood risks in the region. Despite its age, Lower Diversion continues to meet safety guidelines and serves as a testament to effective risk management in the face of climate challenges.

StateNone
River / streamSnake River
NID IDID00340
Owner typeLocal Government
Primary purposeHydroelectric
Dam typeGravity
Year built1982
Dam height14 ft
Dam length1,380 ft
Max storage1,200 AF
Normal storage800 AF
Surface area100.0 ac
Drainage area9,800.0 sq mi
Hazard potentialLow
ConditionNot Available
Last inspectionThu, 28 Sep 2017 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 Lower Diversion -- inflows here typically show up in storage 24-72 hours later.

Track Lower 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.

FAQ

About Lower Diversion

Where does the data for Lower 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.

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Other water bodies near here

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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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