Ylsa Lake Dam dam
Ylsa Lake Dam
Ylsa Lake Dam, located in Monroe County, Illinois, was completed in 1995 and stands at a impressive height of 20 feet with a length of 370 feet. The dam serves primarily for recreational purposes, offering visitors a serene environment to enjoy the surrounding beauty. With a storage capacity of 22 acre-feet and a normal storage of 15 acre-feet, the dam provides a vital resource for the local community.
Managed by a private owner, the dam is regulated by the Illinois Department of Natural Resources (IDNR) and undergoes regular inspections to ensure its safety and structural integrity. The dam is situated on TRIB ROCKHOUSE CREEK and is equipped with an uncontrolled spillway, with a maximum discharge capacity of 31 cubic feet per second. Despite its significant hazard potential, the dam's risk assessment is rated as moderate, indicating that appropriate risk management measures are in place.
Climate and water resource enthusiasts will appreciate the engineering behind Ylsa Lake Dam, which combines stone core and soil foundation in its earth dam structure. The dam's location offers a unique opportunity to observe the intersection of human infrastructure with natural landscapes, providing a valuable case study for understanding the complexities of managing water resources in a changing climate. With its picturesque setting and important role in local recreation, Ylsa Lake Dam showcases the intersection of environmental stewardship and community engagement in water resource management.
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 Ylsa Lake Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Richland Creek Near Hecker | 120 cfs | → |
| Kaskaskia River At New Athens | 7,150 cfs | → |
| Silver Creek Near Freeburg | 155 cfs | → |
| Martigney Creek Near Arnold | 2 cfs | → |
| Mattese Creek Near Mattese | 4 cfs | → |
| Gravois Creek Near Mehlville | 6 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Ylsa Lake Dam.
Boat launches
- Il 13 New Athens
- Randolph County
- Williamson Road Oakville
- North 1st Street 2252, Fayetteville
- Phegley Resort Lane Randolph County
- Lemay Ferry Road Oakville
Campgrounds
- Scott Afb Military
- Fort Kaskaskia State Park
- Randolph County State Conservation Area
- Horseshoe Lake Recreation Area
Paddle runs
Track Ylsa 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 Ylsa Lake Dam
Where does the data for Ylsa 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 Ylsa Lake Dam.