Dam Report

Molstad Lake dam

South Dakota, USA Tr Missonot Ratedi Hazard Low
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Tonight low
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Dam height
19ft
Hazard rating
Low
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Molstad Lake -- None dam
Molstad Lake None · Tr Missonot Ratedi
About this dam

Molstad Lake

Molstad Lake, located in Walworth, South Dakota, is a state-regulated water resource that was completed in 1940 by the Works Progress Administration (WPA). This earth dam structure stands at 19 feet in height and spans 2080 feet in length, with a maximum storage capacity of 2080 acre-feet and a normal storage level of 623 acre-feet. The dam's primary purpose and associated structures are not specified, but it serves as an important water source for the surrounding area.

With a low hazard potential and a moderate risk assessment rating, Molstad Lake is equipped with an uncontrolled spillway that is 66 feet wide. Despite its condition being labeled as "Not Rated," the dam undergoes regular state inspection and enforcement to ensure its safety and functionality. The inspection frequency is set at every 3 years, with the last inspection conducted in September 2019. This water resource is a critical component of the local water infrastructure, supporting the community with its water storage and flood control capabilities.

Managed by the South Dakota Department of Agriculture and Natural Resources (DANR), Molstad Lake plays a crucial role in the region's water management system. The dam's location along the TR MISSONot RatedI river/stream and its proximity to the St. Paul District of the US Army Corps of Engineers underscore its significance in regulating water flow and providing essential services to the area. For water resource and climate enthusiasts, Molstad Lake offers a fascinating glimpse into the intersection of infrastructure, natural resources, and environmental stewardship in South Dakota.

StateNone
River / streamTr Missonot Ratedi
NID IDSD00755
Owner typeState
Dam typeEarth
Year built1940
Dam height19 ft
Dam length2,080 ft
Max storage2,080 AF
Normal storage623 AF
Drainage area24.0 sq mi
Hazard potentialLow
ConditionNot Rated
Last inspectionThu, 26 Sep 2019 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 Molstad Lake -- inflows here typically show up in storage 24-72 hours later.

Track Molstad Lake 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 Molstad Lake

Where does the data for Molstad Lake 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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