Crystal Lake Dam
Crystal Lake Dam is an earth dam located in Jersey County, Illinois, built in 1954. It carries a Low hazard potential classification.
About Crystal Lake Dam
The primary purpose of Crystal Lake Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Unknown (private). It impounds the Trib Piasa Creek near Alton.
The dam stands 24 feet tall and stretches 240 feet across, and has a maximum storage capacity of 87 acre-feet. Completed in 1954, the structure is well into its service life at over 50 years old.
This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected loss of life. The most recent inspection on record was 08/27/2025.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Illinois |
| County | Jersey |
| Nearest City | Alton |
| River/Stream | Trib Piasa Creek |
| Coordinates | 39.09123, -90.23058 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 24 ft |
| Dam Height | 24 ft |
| Dam Length | 240 ft |
| Year Completed | 1954 (72 years old) |
Storage & Hydraulics
| NID Storage | 87 acre-ft |
| Max Storage | 87 acre-ft |
| Normal Storage | 53 acre-ft |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | UNKNOWN |
| Owner Type | Private |
| Hazard Classification | Low |
| Condition Assessment | Not Available |
| Last Inspection | 08/27/2025 |
| Emergency Action Plan | No |
Identifiers
| NID ID | IL00668 |
| Federal ID | IL00668 |
| More Info | State Dam Safety Program |