Twin Lake Dam dam
Twin Lake Dam
Twin Lake Dam is a private structure located in Swansea, Illinois, designed for flood risk reduction purposes along the tributary Wolf Branch. The dam, with a height of 15 feet and a length of 90 feet, provides a maximum storage capacity of 30 acre-feet and normal storage of 20 acre-feet. The dam is of earth construction with a buttress core type and soil foundation, making it a significant hazard potential structure with moderate risk assessment.
Managed by the Illinois Department of Natural Resources (IDNR), the Twin Lake Dam is regulated, permitted, inspected, and enforced by the state agency. The dam features an uncontrolled spillway type with a width of 0 feet, and it has a last inspection date recorded in June 2018 with a frequency of every 3 years. Although the condition assessment is not available, the dam has not had any modifications or emergency action plans prepared, indicating potential areas for improvement in risk management and emergency preparedness.
For water resource and climate enthusiasts, Twin Lake Dam serves as a vital flood risk reduction infrastructure in St. Clair County, Illinois. With its location in a private setting and under state jurisdiction, the dam plays a crucial role in mitigating potential flooding along the Wolf Branch tributary. As efforts continue to enhance risk management measures and emergency preparedness, Twin Lake Dam remains a focal point for maintaining the safety and resilience of the surrounding area in the face of changing climate conditions and water resource challenges.
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.
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 Twin Lake Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Mississippi River At St. Louis | 253,000 cfs | → |
| Judys Branch At Rte 157 At Glen Carbon | 0 cfs | → |
| Silver Creek Near Freeburg | 197 cfs | → |
| Silver Creek Near Troy | 69 cfs | → |
| River Des Peres At St. Louis | 4,340 cfs | → |
| Richland Creek Near Hecker | 75 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Twin Lake Dam.
Track Twin 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.
About Twin Lake Dam
Where does the data for Twin 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 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 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.
Other water bodies near here
Snoflo-tracked reservoirs and dams within driving distance of Twin Lake Dam.