Dam Report

Lower Monumental Lock And Dam dam

Washington, USA Snake River Hazard High
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Dam height
226ft
Hazard rating
High
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Lower Monumental Lock And Dam -- None dam
Lower Monumental Lock And Dam None · Snake River
About this dam

Lower Monumental Lock And Dam

Lower Monumental Lock and Dam, located on the Snake River in Pasco, Washington, serves multiple purposes including navigation, fish and wildlife habitat, hydroelectric power generation, and recreation. Completed in 1969 by the US Army Corps of Engineers, this concrete dam stands at a height of 226 feet and has a length of 3800 feet. With a storage capacity of 432,000 acre-feet and a maximum discharge capacity of 850,000 cubic feet per second, the dam plays a crucial role in managing water levels and mitigating flood risks in the region.

The dam's controlled spillway, 400 feet wide, helps regulate water flow while a single lock facilitates navigation along the river. Lower Monumental Lock and Dam is maintained and operated by the US Army Corps of Engineers, who continuously monitor its condition and manage flood risks associated with the structure. With a high hazard potential and very high risk assessment rating, the agency collaborates with local emergency managers and the public to raise awareness and prepare for potential dam-related emergencies. Despite the inherent risks, this dam remains a vital component of the region's water resource management infrastructure.

As water resource and climate enthusiasts, the Lower Monumental Lock and Dam represents a fascinating intersection of engineering, environmental conservation, and disaster risk management. Its role in balancing competing needs for water use, power generation, and flood protection underscores the complexity and importance of sustainable water resource management in the face of changing climate conditions. With ongoing risk management measures in place and a commitment to public safety, this dam stands as a symbol of resilience in the face of natural challenges.

StateNone
River / streamSnake River
NID IDWA00270
Owner typeFederal
Primary purposeNavigation
Dam typeConcrete
Year built1969
Dam length3,800 ft
Max storage432,000 AF
Normal storage377,000 AF
Surface area6,590.0 ac
Drainage area108,500.0 sq mi
Hazard potentialHigh
ConditionNot Available
Last inspectionTue, 15 Jun 2021 07:00:00 GMT
EAP preparedYes

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 Monumental Lock And Dam -- inflows here typically show up in storage 24-72 hours later.

Track Lower Monumental Lock And Dam 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 Monumental Lock And Dam

Where does the data for Lower Monumental Lock And Dam 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.

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Other water bodies near here

Snoflo-tracked reservoirs and dams within driving distance of Lower Monumental Lock And Dam.

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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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