Dam Report

Allison Street Levee (Mt. Ranier) dam

Maryland, USA Northwest Branch-Tr Hazard High
Today high
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Tonight low
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Dam height
15ft
Hazard rating
High
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Allison Street Levee (Mt. Ranier) -- None dam
Allison Street Levee (Mt. Ranier) None · Northwest Branch-Tr
About this dam

Allison Street Levee (Mt. Ranier)

The Allison Street Levee in Mt. Rainier, Maryland, also known as the 34th Street Bridge or Arundel Canal, is a crucial structure owned by the local government for flood risk reduction along the Northwest Branch-TR river or stream. The levee was designed by Gannett Fleming in 1988 and proposed for an upgrade by McCormick Taylor in 2015. It stands at a height of 15 feet and has a length of 7065 feet, with a spillway type of controlled to manage water flow effectively.

This earth dam is regulated by the Maryland Dam Safety agency and undergoes regular inspections and enforcement to ensure its structural integrity and functionality. The levee has a fair condition assessment as of April 2021, with a high hazard potential due to its location and purpose. The risk assessment for the Allison Street Levee is very high, emphasizing the importance of continued monitoring and management measures to protect the surrounding area from potential flooding events.

Despite its age, the Allison Street Levee plays a critical role in safeguarding Prince George's County, Maryland, and the city of Mt. Rainier from flood risks. As water resource and climate enthusiasts, understanding the significance and maintenance of structures like the Allison Street Levee is essential for preserving the local environment and preventing potential disasters.

StateNone
River / streamNorthwest Branch-Tr
NID IDMD00583
Owner typeLocal Government
Primary purposeFlood Risk Reduction
Dam typeEarth
Year built1988
Dam height15 ft
Dam length7,065 ft
Hazard potentialHigh
ConditionFair
Last inspectionThu, 09 Jan 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 Allison Street Levee (Mt. Ranier) -- inflows here typically show up in storage 24-72 hours later.

Track Allison Street Levee (Mt. Ranier) 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 Allison Street Levee (Mt. Ranier)

Where does the data for Allison Street Levee (Mt. Ranier) 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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