State · United States · USGS · BOR · USACE · CDEC
Pennsylvania
75% average fill
Measured
13
Volume stored
1,145 hm³
Measured capacity
1,527 hm³
Critical
2
Low level
4
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Reservoirs
Sorted by capacityAllegheny Reservoir, PA
Updated 2026-07-31
Youghiogheny River Lake, PA
Updated 2026-07-31
Union City Dam, PA
criticalUpdated 2026-07-31
Conemaugh River Lake, PA
criticalUpdated 2026-07-31
Lake Lynn Outflow, PA
Updated 2026-07-31
East Branch Clarion Lake, PA
Updated 2026-07-31
Shenango River Lake, PA
Updated 2026-07-31
Tionesta Lake, PA
lowUpdated 2026-07-31
Mahoning Creek Lake, PA
lowUpdated 2026-07-31
Loyalhanna Lake, PA
lowUpdated 2026-07-31
Crooked Creek Lake, PA
lowUpdated 2026-07-31
Woodcock Creek Lake, PA
Updated 2026-07-31
Seneca Power Upper Reservoir, PA
Updated 2026-07-31
Storage from official US gauges (USGS, USACE, Bureau of Reclamation, CDEC). Fill % uses design capacity from the National Inventory of Dams where available; a few sites without a match fall back to the 5-year maximum.
About reservoirs in Pennsylvania
As of July 31, 2026, the reservoirs we track across Pennsylvania that report live levels hold roughly 1,145 hm³ of water — about 75.0% of their combined capacity. Taken together, Pennsylvania's reservoirs are within their normal operating range.
Across the region, 2 reservoirs are at critically low levels and 4 are low. Youghiogheny River Lake, PA is the fullest at 101.7%, while Union City Dam, PA is the lowest at 0.2%.
Over the most recent week on record, 1 reservoir rose across Pennsylvania.
Storage figures for Pennsylvania come from USGS · USACE · BOR · CDEC; the most recent reading is from July 31, 2026. Each reservoir below links to its own page with full history and seasonal context.
Pennsylvania at a glance
- Reservoirs tracked
- 13
- Average fill
- 75.0%
- Water stored
- 1,145 hm³
- Combined capacity
- 1,527 hm³
- At critically low levels
- 2
- Fullest
- Youghiogheny River Lake, PA (101.7%)
- Lowest
- Union City Dam, PA (0.2%)
- Last updated
- July 31, 2026
Frequently asked questions
How full are reservoirs in Pennsylvania right now?
As of July 31, 2026, the reservoirs tracked in Pennsylvania that report live levels are 75.0% full overall, holding about 1,145 hm³ of water.
How many reservoirs are there in Pennsylvania?
reservoirs.earth tracks 13 reservoirs in Pennsylvania, with a combined storage capacity of 1,527 hm³.
Which reservoir in Pennsylvania is the fullest?
Youghiogheny River Lake, PA is currently the fullest reservoir in Pennsylvania, at 101.7% of capacity.
Which reservoir in Pennsylvania is the lowest?
Union City Dam, PA is currently the lowest in Pennsylvania, at 0.2% of capacity.
Where does the reservoir data for Pennsylvania come from?
All storage figures for Pennsylvania come from USGS · USACE · BOR · CDEC, an official source, last updated July 31, 2026.