Reservoir · Illinois · United States · USACE CWMS
Sub Casey
10.1% full
Capacity
8.09 hm³
Volume stored
1 hm³
Coordinates
38.188°N, 88.927°W
Last updated
2026-09-14
Current fill
10.1%vs 7 days ago
+3.0%gaining
vs 1 year ago
N/A7-day trend
↑rising
Data source: USACE CWMS — US Army Corps of Engineers — daily reservoir storage volume. Design capacity is unavailable for this site, so fill % is estimated against the 5-year maximum storage and may overstate fullness. Last reading: 2026-09-14.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 38.188, -88.927 · Open in Google Maps
About Sub Casey
As of September 14, 2026, Sub Casey is filled to 10.1% of its total capacity, holding roughly 1 hm³ of water out of a maximum 8 hm³. At this level the reservoir is critically low.
Over the most recent week on record the fill level has risen by 3.0 percentage points.
Across the readings we hold for Sub Casey — 198 data points between September 15, 2021 and September 14, 2026 — the level has ranged from a low of 4.5% (August 2, 2026) to a high of 100.0% (December 19, 2021). On average the reservoir is fullest around December and at its lowest around August.
It is operated by USACE primarily for multiple purposes. It lies within the Illinois basin at 38.188°N, 88.927°W.
Key facts
- Current fill level
- 10.1%
- Water stored
- 1 hm³
- Total capacity
- 8 hm³
- 7-day change
- ▲ 3.0 pts
- Primary use
- Multipurpose
- River basin
- Illinois
- Operator
- USACE
- Coordinates
- 38.188°N, 88.927°W
- Last updated
- September 14, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 14 Sep 2026 | 10.1% | 1 |
| 13 Sep 2026 | 10.2% | 1 |
| 12 Sep 2026 | 10.0% | 1 |
| 11 Sep 2026 | 9.5% | 1 |
| 10 Sep 2026 | 8.5% | 1 |
| 9 Sep 2026 | 6.9% | 1 |
| 8 Sep 2026 | 7.1% | 1 |
| 7 Sep 2026 | 7.1% | 1 |
| 6 Sep 2026 | 7.4% | 1 |
| 5 Sep 2026 | 7.4% | 1 |
| 4 Sep 2026 | 7.5% | 1 |
| 3 Sep 2026 | 7.6% | 1 |