Structure No. 12 dam
Structure No. 12
Structure No. 12, also known as Dutchman Lake, is a federal-owned dam located in Johnson County, Illinois. Managed by the USDA NRCS, this earth dam was completed in 1974 for the primary purposes of recreation and water supply. With a height of 54 feet and a length of 1450 feet, the dam provides a maximum storage capacity of 4432 acre-feet and serves a drainage area of 11 square miles.
The dam's spillway type is controlled with a width of 300 feet, and the outlet gates are equipped with valves for water release. Despite being classified as having a significant hazard potential and a very high risk assessment level, the dam's condition assessment is currently listed as not rated. The last inspection was conducted in September 2016, with no specific inspection frequency provided.
This structure, situated along Dutchman Creek, is under the regulation of the IDNR and the Forest Service, with funding and construction support from various federal agencies. As a popular recreational spot in the area, Structure No. 12 plays a crucial role in water supply management and offers opportunities for outdoor activities amid its natural surroundings.
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.
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
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.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day temperature & precipitation
Daily temperatures, snow, and rain projected over the next two weeks.
Nearby streamflow gauges
USGS streamgauges around Structure No. 12 -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| South Fork Saline River Nr Carrier Mills | 942 cfs | → |
| Lusk Creek Near Eddyville | 14 cfs | → |
| Cache River At Forman | 3,860 cfs | → |
| Crab Orchard Creek Near Marion | 4 cfs | → |
| Ohio River At Metropolis | 444,000 cfs | → |
| Bayou Creek Near Grahamville | 5 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Structure No. 12.
Campgrounds
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Fishing spots
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River runs
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About Structure No. 12
Where does the data for Structure No. 12 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 Significant 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 below 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.
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.