Dam Report

Willow Lake Dam dam

Iowa, USA Tr-Willow Creek Hazard Low
Today high
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Tonight low
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Dam height
31ft
Hazard rating
Low
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Willow Lake Dam -- None dam
Willow Lake Dam None · Tr-Willow Creek
About this dam

Willow Lake Dam

Willow Lake Dam, located in Harrison County, Iowa, was completed in 1976 and is owned by the local government. The dam, designed by DESIGN ENGINEERING,INC., serves the primary purpose of debris control along the TR-WILLOW CREEK river or stream. With a height of 31 feet and a length of 390 feet, the earth dam has a storage capacity of 44 acre-feet and a surface area of 19 acres.

Managed by the Iowa Department of Natural Resources, Willow Lake Dam is regulated, inspected, and enforced by the state. The dam's hazard potential is rated as low, with a moderate risk assessment score. While the dam's condition is currently not rated, it meets the necessary guidelines for emergency action planning. The dam also provides recreational opportunities in addition to its debris control function.

Water resource and climate enthusiasts will appreciate the environmental impact and importance of Willow Lake Dam in managing water flow and debris along TR-WILLOW CREEK. As a key infrastructure in Harrison County, Iowa, the dam plays a crucial role in ensuring public safety and maintaining the ecological balance of the area. With its low hazard potential and moderate risk assessment, Willow Lake Dam stands as a testament to effective water resource management and engineering in the region.

StateNone
River / streamTr-Willow Creek
NID IDIA01566
Owner typeLocal Government
Primary purposeDebris Control
Dam typeEarth
Year built1976
Dam height31 ft
Dam length390 ft
Max storage44 AF
Normal storage21 AF
Surface area19.0 ac
Drainage area0.2 sq mi
Hazard potentialLow
ConditionNot Rated

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 Willow Lake Dam -- inflows here typically show up in storage 24-72 hours later.

Track Willow Lake 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 Willow Lake Dam

Where does the data for Willow Lake 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 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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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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