Lake Hopatcong Water Level

New Jersey · updated daily from the U.S. Geological Survey

9.18 ft

Lake Hopatcong is current reading available and steady (-0.14 ft in the last 7 days).

Change since yesterday: -0.02 ft

Reading as of 2026-08-15

Where Lake Hopatcong sits historically

TODAY 9.18 ftRECORD LOW8.78 ft2026-04-17RECORD HIGH9.38 ft2026-08-04

Today's level compared with every reading in our 0.3-year record for this lake.

Since yesterday

-0.02 ft

7-day change

-0.14 ft

30-day change

+0.12 ft

1-year change

— ft

Last 30 days

2026-07-169.0–9.4 ft2026-08-15

Last 12 months

2026-04-178.7–9.5 ft2026-08-15

Lake Hopatcong records and averages

Current level9.18 ft
Record high9.38 ft (2026-08-04)
Record low8.78 ft (2026-04-17)
Average of all readings9.09 ft
Data span0.3 years (121 readings)

Frequently asked questions

Is Lake Hopatcong full right now?

As of 2026-08-15, Lake Hopatcong sits at 9.18 ft, which is current reading available.Over the past 30 days the level has risen 0.12 ft.

What is the water level at Lake Hopatcong today?

The most recent reading is 9.18 ft (2026-08-15), sourced from the U.S. Geological Survey. Readings on this page refresh automatically as the agency publishes new data.

What is the highest Lake Hopatcong has ever been?

The highest level in our records is 9.38 ft on 2026-08-04. The lowest is 8.78 ft on 2026-04-17. Our record covers about 0.3 years of readings.

Why is Lake Hopatcong changing right now?

Reservoir levels move for four main reasons: rainfall and runoff into the basin, releases through the dam for downstream water supply, power generation or flood control, evaporation during hot months, and seasonal drawdown schedules set by the operating agency. Lake Hopatcong has risen 0.12 ft over the past 30 days. For the operational reason on any given week, check the U.S. Geological Survey directly.

How much has Lake Hopatcong changed over the past year?

Year-over-year comparison is not available for this lake yet. The full-history chart above covers 0.3 years, with a record high of 9.38 ft and a record low of 8.78 ft.

Nearby lakes in New Jersey

Boonton Reservoir water level
305.44 ft · falling
Wanaque Reservoir water level
295.49 ft · falling
Greenwood Lake water level
10.12 ft · steady
Woodcliff Lake water level
94.55 ft · falling
Oradell Reservoir water level
22.77 ft · falling
Lake Tappan water level
55.05 ft · falling

Source: the U.S. Geological Survey. Readings are provisional and subject to revision by the publishing agency. All New Jersey lake levels.