Happy Hollow Lake Dam dam
Happy Hollow Lake Dam
Happy Hollow Lake Dam, located in Dahinda, Illinois, along the tributary of Spoon River, is a private-owned structure with a primary purpose of recreation. Built in 1940 by JACOB A. HARMAN, this earth dam stands at a height of 52 feet and has a length of 260 feet, providing a storage capacity of 232 acre-feet. The dam is regulated by the Illinois Department of Natural Resources (IDNR) and undergoes regular inspections and enforcement to ensure its safety and compliance.
With a hazard potential rated as significant and a moderate risk assessment, Happy Hollow Lake Dam is a crucial structure in the region. The dam features uncontrolled spillway and outlet gates and is designed to withstand the demands of recreational activities while ensuring the safety of nearby communities. Despite its age, the dam has not had a condition assessment available, but it is inspected every three years to maintain its structural integrity and mitigate any potential risks.
For water resource and climate enthusiasts, Happy Hollow Lake Dam serves as a fascinating case study in dam management and regulation. Its location in Knox County, Illinois, highlights the importance of private ownership in maintaining recreational water resources. As climate change continues to impact water infrastructure, the management of dams like Happy Hollow Lake Dam becomes increasingly vital to ensure the safety and sustainability of water resources for future generations.
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 Happy Hollow Lake Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Indian Creek Near Wyoming | 13 cfs | → |
| Spoon River At London Mills | 441 cfs | → |
| Edwards River Near Orion | 66 cfs | → |
| Illinois River At Kingston Mines | 12,400 cfs | → |
| Fondulac Creek Near East Peoria | · | → |
| Spoon River At Seville | 594 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Happy Hollow Lake Dam.
Boat launches
- Gatewood Lane Galesburg
- Lakeland Park Road 26005, Canton
- Sebree Road Fulton County
- West Pine Street 1, Chillicothe
Track Happy Hollow 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 Happy Hollow Lake Dam
Where does the data for Happy Hollow 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 Happy Hollow Lake Dam.