Joliet West Side Wastewater Treatment Plant Dam is an earth dam located in Will County, Illinois. It carries a Low hazard potential classification.
Dam profile
NID height · 25 ft25 ft tall and 1,000 ft long, taller than 50% of U.S. dams with a recorded height. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic embankment section and the water level is illustrative.
About Joliet West Side Wastewater Treatment Plant Dam
The primary purpose of Joliet West Side Wastewater Treatment Plant Dam is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by City of Joliet (local government). It impounds the Des Plaines River - Offstream near Joliet.
The dam stands 25 feet tall and stretches 1,000 feet across, creates a reservoir covering 5 acres, has a maximum storage capacity of 77 acre-feet, and collects water from a drainage area of 0 square miles.
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 06/03/2025.
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Location
| State | Illinois |
| County | Will |
| Nearest City | Joliet |
| River/Stream | Des Plaines River - Offstream |
| Coordinates | 41.45744, -88.18431 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 25 ft |
| Dam Height | 25 ft |
| Dam Length | 1,000 ft |
Storage & Hydraulics
| NID Storage | 77 acre-ft |
| Max Storage | 77 acre-ft |
| Surface Area | 5 acres |
| Drainage Area | 0 sq mi |
| Spillway Type | None |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | City of Joliet |
| Owner Type | Local Government |
| Hazard Classification | Low |
| Condition Assessment | Not assessed |
| Last Inspection | 06/03/2025 |
| Emergency Action Plan | No |
Identifiers
| NID ID | IL55049 |
| Federal ID | IL55049 |
| More Info | State Dam Safety Program |