Dam Report

Lewandowski Dam dam

South Dakota, USA Tr.-Little Minnesota River Hazard Low
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Tonight low
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Dam height
29ft
Hazard rating
Low
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Lewandowski Dam -- None dam
Lewandowski Dam None · Tr.-Little Minnesota River
About this dam

Lewandowski Dam

Lewandowski Dam, located on the TR.-LITTLE MINNESOTA RIVER in Roberts, South Dakota, is a privately owned structure designed by USDA NRCS and completed in 2006. This earth dam stands at a height of 29 feet, with a storage capacity of 33 acre-feet and a maximum discharge of 325 cubic feet per second. The dam serves a primary purpose of water resource management, with a low hazard potential and a moderate risk assessment rating.

Managed by the South Dakota Department of Environment and Natural Resources (DENR), Lewandowski Dam is regulated, permitted, inspected, and enforced by the state. The dam features an uncontrolled spillway with a width of 24 feet and does not have outlet gates. Despite being in good condition and not rated for condition assessment, the structure's risk management measures and emergency action plan status remain undisclosed. Its location within the Omaha District further underscores its importance in mitigating the impact of climate change on water resources in the region.

Overall, Lewandowski Dam plays a crucial role in water resource management and climate resilience efforts in South Dakota. As a vital structure along the TR.-LITTLE MINNESOTA RIVER, it stands as a testament to the collaboration between private owners, government agencies, and design entities in safeguarding the local community against potential water-related hazards. With its strategic placement and functional design, the dam serves as a valuable asset in regulating water flow, storing essential water resources, and maintaining the ecological balance of the surrounding area.

StateNone
River / streamTr.-Little Minnesota River
NID IDSD02545
Owner typePrivate
Dam typeEarth
Year built2006
Dam height29 ft
Dam length160 ft
Max storage33 AF
Normal storage14 AF
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 Lewandowski Dam -- inflows here typically show up in storage 24-72 hours later.

Track Lewandowski 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 Lewandowski Dam

Where does the data for Lewandowski 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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