New Jersey / Waters /
Lake Hopatcong
Reservoir in New Jersey, near Hopatcong, Landing and Shore Hills
Current status
No current status shown
No current status is assigned to this water outline. Check the water page for reports and any estimated downstream stretches. Why this status, and its source
Map sources: water outlines and launches from OpenBoatLaunch and OpenStreetMap contributors (Open Database License); wastewater outlets from EPA and state records; downstream estimates by DirtyWaterWatch using U.S. Geological Survey maps and flow data. Base map: OpenFreeMap and OpenMapTiles.
Square boat markers mark boat launches listed by OpenBoatLaunch.
Bookmark this water page and check it before each trip · Report a missing notice or error
About this status
Why this status: No current status: no report we track sets a status on this water outline now.
How long each status lasts, and why
Sources checked: NJDEP (last successful check 2026-11-02 21:19 UTC); Division of Water Monitoring, Standards and Pesticide Control (last successful check 2026-11-02 21:19 UTC). Status by DirtyWaterWatch, updated 2026-11-02 21:26 UTC.
No status does not mean the water is safe. Follow posted signs and local health advice.
Updated .
The last 90 days
- Discharge or advisory reported: to 9 reports: NJDEP Harmful Algal Bloom Program (Division of Water Monitoring, Standards and Pesticide Control) 8, New Jersey Cooperative Coastal Monitoring Program (NJDEP) 1
Show records
The records are also in the report table on this page.
- Cyanobacteria advisory (harmful blue-green algae), started Aug 25, 2026, 11:58 AM EDT
- Cyanobacteria advisory (harmful blue-green algae), started Aug 25, 2026, 10:19 AM EDT
- Cyanobacteria advisory (harmful blue-green algae), started Aug 25, 2026, 10:09 AM EDT
- Beach advisory, started Aug 24, 2026
- Cyanobacteria advisory (harmful blue-green algae), started Aug 18, 2026, 9:37 AM EDT
- Cyanobacteria advisory (harmful blue-green algae), started Aug 18, 2026, 9:30 AM EDT
- Cyanobacteria advisory (harmful blue-green algae), started Aug 18, 2026, 9:11 AM EDT
- Cyanobacteria advisory (harmful blue-green algae), started Aug 18, 2026, 9:06 AM EDT
- Cyanobacteria advisory (harmful blue-green algae), started Aug 18, 2026, 8:38 AM EDT
- Discharge or advisory reported: to 3 reports: New Jersey Cooperative Coastal Monitoring Program (NJDEP) 3
Show records
The records are also in the report table on this page.
Source: DirtyWaterWatch calculations using the reports named above and the published status rules. Updated 2026-11-02 21:26 UTC.
Reported discharges over time
- Hours with a discharge or advisory status on the Lake Hopatcong in New Jersey, last 12 months2,487Reported on the Lake Hopatcong in New Jersey: 0 · Arriving from outfalls upstream, estimated: 0December 2025 to November 2026Red hours by the map's rules: each discharge to its reported end plus the state's post-discharge period; overlapping hours count once.
- 2026 season with a discharge or advisory status on the Lake Hopatcong in New Jersey56%May to October 2026Share of May 1 to October 31 hours with red status by the map's rules, of the hours a source covered.
- Records behind the last-90-days strip for the Lake Hopatcong in New Jersey12Reported on the Lake Hopatcong in New Jersey: 12 · Arriving from outfalls upstream, estimated: 0last 90 daysEvery distinct record the strip lists for its red, yellow and unresolved hours, notices and unresolved reports included; counted as the strip counts them.
Hours with a discharge or advisory status per month
Hours when this water had a discharge or advisory status under DirtyWaterWatch rules.
- Discharge or advisory reported
- No tracked source for this period
- Incomplete source coverage
No tracked source covers January 2022 to March 2025. 7 discharges reported to last more than 31 days are counted as 31 days.
Sources: nj-beaches; nj-hab. Records cover April 2, 2025 to November 2, 2026.
Show table
| Month | Hours with a discharge or advisory status | Hours from post-discharge periods | Hours from official advisories only | Hours in the month | Coverage |
|---|---|---|---|---|---|
| January 2022 | 0 | 0 | 0 | 744 | No tracked source for this period |
| February 2022 | 0 | 0 | 0 | 672 | No tracked source for this period |
| March 2022 | 0 | 0 | 0 | 744 | No tracked source for this period |
| April 2022 | 0 | 0 | 0 | 720 | No tracked source for this period |
| May 2022 | 0 | 0 | 0 | 744 | No tracked source for this period |
| June 2022 | 0 | 0 | 0 | 720 | No tracked source for this period |
| July 2022 | 0 | 0 | 0 | 744 | No tracked source for this period |
| August 2022 | 0 | 0 | 0 | 744 | No tracked source for this period |
| September 2022 | 0 | 0 | 0 | 720 | No tracked source for this period |
| October 2022 | 0 | 0 | 0 | 744 | No tracked source for this period |
| November 2022 | 0 | 0 | 0 | 720 | No tracked source for this period |
| December 2022 | 0 | 0 | 0 | 744 | No tracked source for this period |
| January 2023 | 0 | 0 | 0 | 744 | No tracked source for this period |
| February 2023 | 0 | 0 | 0 | 672 | No tracked source for this period |
| March 2023 | 0 | 0 | 0 | 744 | No tracked source for this period |
| April 2023 | 0 | 0 | 0 | 720 | No tracked source for this period |
| May 2023 | 0 | 0 | 0 | 744 | No tracked source for this period |
| June 2023 | 0 | 0 | 0 | 720 | No tracked source for this period |
| July 2023 | 0 | 0 | 0 | 744 | No tracked source for this period |
| August 2023 | 0 | 0 | 0 | 744 | No tracked source for this period |
| September 2023 | 0 | 0 | 0 | 720 | No tracked source for this period |
| October 2023 | 0 | 0 | 0 | 744 | No tracked source for this period |
| November 2023 | 0 | 0 | 0 | 720 | No tracked source for this period |
| December 2023 | 0 | 0 | 0 | 744 | No tracked source for this period |
| January 2024 | 0 | 0 | 0 | 744 | No tracked source for this period |
| February 2024 | 0 | 0 | 0 | 696 | No tracked source for this period |
| March 2024 | 0 | 0 | 0 | 744 | No tracked source for this period |
| April 2024 | 0 | 0 | 0 | 720 | No tracked source for this period |
| May 2024 | 0 | 0 | 0 | 744 | No tracked source for this period |
| June 2024 | 0 | 0 | 0 | 720 | No tracked source for this period |
| July 2024 | 0 | 0 | 0 | 744 | No tracked source for this period |
| August 2024 | 0 | 0 | 0 | 744 | No tracked source for this period |
| September 2024 | 0 | 0 | 0 | 720 | No tracked source for this period |
| October 2024 | 0 | 0 | 0 | 744 | No tracked source for this period |
| November 2024 | 0 | 0 | 0 | 720 | No tracked source for this period |
| December 2024 | 0 | 0 | 0 | 744 | No tracked source for this period |
| January 2025 | 0 | 0 | 0 | 744 | No tracked source for this period |
| February 2025 | 0 | 0 | 0 | 672 | No tracked source for this period |
| March 2025 | 0 | 0 | 0 | 744 | No tracked source for this period |
| April 2025 | 0 | 0 | 0 | 720 | Incomplete source coverage |
| May 2025 | 0 | 0 | 0 | 744 | |
| June 2025 | 637 | 0 | 637 | 720 | |
| July 2025 | 170 | 0 | 170 | 744 | |
| August 2025 | 744 | 0 | 744 | 744 | |
| September 2025 | 273 | 0 | 273 | 720 | |
| October 2025 | 0 | 0 | 0 | 744 | |
| November 2025 | 0 | 0 | 0 | 720 | |
| December 2025 | 0 | 0 | 0 | 744 | |
| January 2026 | 0 | 0 | 0 | 744 | |
| February 2026 | 0 | 0 | 0 | 672 | |
| March 2026 | 0 | 0 | 0 | 744 | |
| April 2026 | 0 | 0 | 0 | 720 | |
| May 2026 | 0 | 0 | 0 | 744 | |
| June 2026 | 15 | 0 | 15 | 720 | |
| July 2026 | 744 | 0 | 744 | 744 | |
| August 2026 | 471 | 0 | 471 | 744 | |
| September 2026 | 720 | 0 | 720 | 720 | |
| October 2026 | 536 | 0 | 536 | 744 | |
| November 2026 | 0 | 0 | 0 | 42 |
Hours with a discharge or advisory status per year
Hours with a discharge or advisory status each year under DirtyWaterWatch rules; 2026 to date.
- Discharge or advisory reported
- Incomplete source coverage
7 discharges reported to last more than 31 days are counted as 31 days.
Sources: nj-beaches; nj-hab. Records cover April 2, 2025 to November 2, 2026.
Show table
| Year | Hours with a discharge or advisory status | Share of the year | Coverage |
|---|---|---|---|
| 2025 | 1,824 | 20.8% | Incomplete source coverage |
| 2026 | 2,487 | 33.9% |
How these charts are counted
We count each discharge once. Where a source publishes notices and confirmed reports, we use confirmed reports for an operator's month when available; otherwise we use notices. We combine revisions and exclude duplicate state reports copied by the U.S. Environmental Protection Agency (EPA). Monthly and yearly totals appear separately. Status hours follow this site's rules. Shaded gaps mean missing coverage, not zero discharges.
- nj-beaches: records from May 9, 2025 to the latest update
- nj-hab: records from April 2, 2025 to the latest update
Reports linked to Lake Hopatcong
| Start | End | Sewer operator | Outlet | Type | Volume | Source | Links |
|---|---|---|---|---|---|---|---|
| Aug 25, 2026, 11:58 AM EDT | still listed as in effect | not stated | Not provided | Cyanobacteria advisory (harmful blue-green algae) | volume not reported | NJDEP Harmful Algal Bloom Program (Division of Water Monitoring, Standards and Pesticide Control), record 8ce38351-dbc3-4b55-a35e-200a7e5561b0, updated by the source Oct 9, 2026, 8:00 AM EDT, retrieved 2026-11-02 21:19 UTC · Read the original notice | Read report: Cyanobacteria advisory (harmful blue-green algae), , Aug 25, 2026, 11:58 AM EDT · Map |
| Aug 25, 2026, 10:19 AM EDT | still listed as in effect | not stated | Not provided | Cyanobacteria advisory (harmful blue-green algae) | volume not reported | NJDEP Harmful Algal Bloom Program (Division of Water Monitoring, Standards and Pesticide Control), record 85731b11-3a4e-4b87-8f1c-eea69f8428d5, updated by the source Aug 29, 2026, 8:00 AM EDT, retrieved 2026-11-02 21:19 UTC · Read the original notice | Read report: Cyanobacteria advisory (harmful blue-green algae), , Aug 25, 2026, 10:19 AM EDT · Map |
| Aug 25, 2026, 10:09 AM EDT | still listed as in effect | not stated | Not provided | Cyanobacteria advisory (harmful blue-green algae) | volume not reported | NJDEP Harmful Algal Bloom Program (Division of Water Monitoring, Standards and Pesticide Control), record 01badc00-322a-4042-ada9-85023b966669, updated by the source Aug 29, 2026, 8:00 AM EDT, retrieved 2026-11-02 21:19 UTC · Read the original notice | Read report: Cyanobacteria advisory (harmful blue-green algae), , Aug 25, 2026, 10:09 AM EDT · Map |
| Aug 24, 2026 | Aug 25, 2026 | not stated | Not provided | Beach advisory | volume not reported | New Jersey Cooperative Coastal Monitoring Program (NJDEP), record SU191203:beach_advisory:2026-08-24, updated by the source Nov 2, 2026, 3:47 PM EST, retrieved 2026-11-02 21:19 UTC · Read the original notice | Read report: Beach advisory, , Aug 24, 2026 · Map |
| Aug 18, 2026, 9:37 AM EDT | still listed as in effect | not stated | Not provided | Cyanobacteria advisory (harmful blue-green algae) | volume not reported | NJDEP Harmful Algal Bloom Program (Division of Water Monitoring, Standards and Pesticide Control), record f8a12155-b0a3-4895-9ecd-af2cd31c6e16, updated by the source Aug 29, 2026, 8:00 AM EDT, retrieved 2026-11-02 21:19 UTC · Read the original notice | Read report: Cyanobacteria advisory (harmful blue-green algae), , Aug 18, 2026, 9:37 AM EDT · Map |
| Aug 18, 2026, 9:30 AM EDT | still listed as in effect | not stated | Not provided | Cyanobacteria advisory (harmful blue-green algae) | volume not reported | NJDEP Harmful Algal Bloom Program (Division of Water Monitoring, Standards and Pesticide Control), record 2ac30e79-d3e6-4a55-b71b-ad745f608cc0, updated by the source Aug 29, 2026, 8:00 AM EDT, retrieved 2026-11-02 21:19 UTC · Read the original notice | Read report: Cyanobacteria advisory (harmful blue-green algae), , Aug 18, 2026, 9:30 AM EDT · Map |
| Aug 18, 2026, 9:11 AM EDT | still listed as in effect | not stated | Not provided | Cyanobacteria advisory (harmful blue-green algae) | volume not reported | NJDEP Harmful Algal Bloom Program (Division of Water Monitoring, Standards and Pesticide Control), record 5da36837-6104-4817-bc6c-0fde3dc7e3dc, updated by the source Aug 28, 2026, 8:00 AM EDT, retrieved 2026-11-02 21:19 UTC · Read the original notice | Read report: Cyanobacteria advisory (harmful blue-green algae), , Aug 18, 2026, 9:11 AM EDT · Map |
| Aug 18, 2026, 9:06 AM EDT | still listed as in effect | not stated | Not provided | Cyanobacteria advisory (harmful blue-green algae) | volume not reported | NJDEP Harmful Algal Bloom Program (Division of Water Monitoring, Standards and Pesticide Control), record 008f5229-03ea-43b1-a7ed-5956ef799109, updated by the source Aug 28, 2026, 8:00 AM EDT, retrieved 2026-11-02 21:19 UTC · Read the original notice | Read report: Cyanobacteria advisory (harmful blue-green algae), , Aug 18, 2026, 9:06 AM EDT · Map |
| Aug 18, 2026, 8:38 AM EDT | still listed as in effect | not stated | Not provided | Cyanobacteria advisory (harmful blue-green algae) | volume not reported | NJDEP Harmful Algal Bloom Program (Division of Water Monitoring, Standards and Pesticide Control), record 91d0e741-1148-4310-bea7-aadb5bab4090, updated by the source Aug 29, 2026, 8:00 AM EDT, retrieved 2026-11-02 21:19 UTC · Read the original notice | Read report: Cyanobacteria advisory (harmful blue-green algae), , Aug 18, 2026, 8:38 AM EDT · Map |
| Aug 5, 2026 | Aug 6, 2026 | not stated | Not provided | Beach advisory | volume not reported | New Jersey Cooperative Coastal Monitoring Program (NJDEP), record SU191201:beach_advisory:2026-08-05, updated by the source Nov 2, 2026, 3:47 PM EST, retrieved 2026-11-02 21:19 UTC · Read the original notice | Read report: Beach advisory, , Aug 5, 2026 · Map |
| Aug 3, 2026 | Aug 4, 2026 | not stated | Not provided | Beach advisory | volume not reported | New Jersey Cooperative Coastal Monitoring Program (NJDEP), record MR143607:beach_advisory:2026-08-03, updated by the source Nov 2, 2026, 3:47 PM EST, retrieved 2026-11-02 21:19 UTC · Read the original notice | Read report: Beach advisory, , Aug 3, 2026 · Map |
| Aug 3, 2026 | Aug 4, 2026 | not stated | Not provided | Beach advisory | volume not reported | New Jersey Cooperative Coastal Monitoring Program (NJDEP), record MR143601:beach_advisory:2026-08-03, updated by the source Nov 2, 2026, 3:47 PM EST, retrieved 2026-11-02 21:19 UTC · Read the original notice | Read report: Beach advisory, , Aug 3, 2026 · Map |
| Jul 22, 2026 | Jul 23, 2026 | not stated | Not provided | Beach advisory | volume not reported | New Jersey Cooperative Coastal Monitoring Program (NJDEP), record SU191201:beach_advisory:2026-07-22, updated by the source Nov 2, 2026, 3:47 PM EST, retrieved 2026-11-02 21:19 UTC · Read the original notice | Read report: Beach advisory, , Jul 22, 2026 · Map |
| Jul 16, 2026 | Jul 17, 2026 | not stated | Not provided | Beach closure | volume not reported | New Jersey Cooperative Coastal Monitoring Program (NJDEP), record SU191201:beach_closure:2026-07-16, updated by the source Nov 2, 2026, 3:47 PM EST, retrieved 2026-11-02 21:19 UTC · Read the original notice | Read report: Beach closure, , Jul 16, 2026 · Map |
| Jul 14, 2026, 9:09 AM EDT | Aug 4, 2026, 9:37 AM EDT | not stated | Not provided | Cyanobacteria advisory (harmful blue-green algae) | volume not reported | NJDEP Harmful Algal Bloom Program (Division of Water Monitoring, Standards and Pesticide Control), record 4df18703-075d-45ea-b067-a367569598b1, updated by the source Jul 25, 2026, 12:00 PM EDT, retrieved 2026-11-02 21:19 UTC · Read the original notice | Read report: Cyanobacteria advisory (harmful blue-green algae), , Jul 14, 2026, 9:09 AM EDT · Map |
| Jul 14, 2026 | Jul 15, 2026 | not stated | Not provided | Beach advisory | volume not reported | New Jersey Cooperative Coastal Monitoring Program (NJDEP), record SU191201:beach_advisory:2026-07-14, updated by the source Nov 2, 2026, 3:47 PM EST, retrieved 2026-11-02 21:19 UTC · Read the original notice | Read report: Beach advisory, , Jul 14, 2026 · Map |
| Jul 13, 2026 | Jul 14, 2026 | not stated | Not provided | Beach advisory | volume not reported | New Jersey Cooperative Coastal Monitoring Program (NJDEP), record MR143607:beach_advisory:2026-07-13, updated by the source Nov 2, 2026, 3:47 PM EST, retrieved 2026-11-02 21:19 UTC · Read the original notice | Read report: Beach advisory, , Jul 13, 2026 · Map |
| Jul 8, 2026 | Jul 9, 2026 | not stated | Not provided | Beach advisory | volume not reported | New Jersey Cooperative Coastal Monitoring Program (NJDEP), record SU191201:beach_advisory:2026-07-08, updated by the source Nov 2, 2026, 3:47 PM EST, retrieved 2026-11-02 21:19 UTC · Read the original notice | Read report: Beach advisory, , Jul 8, 2026 · Map |
| Jun 30, 2026, 9:51 AM EDT | still listed as in effect | not stated | Not provided | Cyanobacteria advisory (harmful blue-green algae) | volume not reported | NJDEP Harmful Algal Bloom Program (Division of Water Monitoring, Standards and Pesticide Control), record a8c3b927-ed85-4bda-bd9a-bcd9fccac0c6, updated by the source Jul 4, 2026, 12:00 PM EDT, retrieved 2026-11-02 21:19 UTC · Read the original notice | Read report: Cyanobacteria advisory (harmful blue-green algae), , Jun 30, 2026, 9:51 AM EDT · Map |
| Jun 30, 2026, 9:42 AM EDT | still listed as in effect | not stated | Not provided | Cyanobacteria advisory (harmful blue-green algae) | volume not reported | NJDEP Harmful Algal Bloom Program (Division of Water Monitoring, Standards and Pesticide Control), record 1b9bbc29-d94c-40b4-b0f7-8484dc4f2602, updated by the source Jul 4, 2026, 12:00 PM EDT, retrieved 2026-11-02 21:19 UTC · Read the original notice | Read report: Cyanobacteria advisory (harmful blue-green algae), , Jun 30, 2026, 9:42 AM EDT · Map |
| Jun 30, 2026, 9:35 AM EDT | still listed as in effect | not stated | Not provided | Cyanobacteria advisory (harmful blue-green algae) | volume not reported | NJDEP Harmful Algal Bloom Program (Division of Water Monitoring, Standards and Pesticide Control), record ad31d2e1-99bb-48cb-9ccb-cfb4289b8892, updated by the source Jul 4, 2026, 12:00 PM EDT, retrieved 2026-11-02 21:19 UTC · Read the original notice | Read report: Cyanobacteria advisory (harmful blue-green algae), , Jun 30, 2026, 9:35 AM EDT · Map |
| Jun 30, 2026, 9:29 AM EDT | Aug 4, 2026, 10:05 AM EDT | not stated | Not provided | Cyanobacteria advisory (harmful blue-green algae) | volume not reported | NJDEP Harmful Algal Bloom Program (Division of Water Monitoring, Standards and Pesticide Control), record 2b767f44-448c-42f1-b8de-7bc02981134a, updated by the source Jul 25, 2026, 12:00 PM EDT, retrieved 2026-11-02 21:19 UTC · Read the original notice | Read report: Cyanobacteria advisory (harmful blue-green algae), , Jun 30, 2026, 9:29 AM EDT · Map |
| Jun 30, 2026, 9:05 AM EDT | still listed as in effect | not stated | Not provided | Cyanobacteria advisory (harmful blue-green algae) | volume not reported | NJDEP Harmful Algal Bloom Program (Division of Water Monitoring, Standards and Pesticide Control), record 31f9325d-6808-4ac6-ba86-ed2240d23e72, updated by the source Jul 4, 2026, 12:00 PM EDT, retrieved 2026-11-02 21:19 UTC · Read the original notice | Read report: Cyanobacteria advisory (harmful blue-green algae), , Jun 30, 2026, 9:05 AM EDT · Map |
| Jun 30, 2026, 8:47 AM EDT | Jul 25, 2026, 12:00 PM EDT | not stated | Not provided | Cyanobacteria advisory (harmful blue-green algae) | volume not reported | NJDEP Harmful Algal Bloom Program (Division of Water Monitoring, Standards and Pesticide Control), record 32a52d8c-3a2f-4392-bc07-5c0eac1f69ea, updated by the source Jul 4, 2026, 12:00 PM EDT, retrieved 2026-11-02 21:19 UTC · Read the original notice | Read report: Cyanobacteria advisory (harmful blue-green algae), , Jun 30, 2026, 8:47 AM EDT · Map |
| Jun 30, 2026, 8:43 AM EDT | Jul 25, 2026, 12:00 PM EDT | not stated | Not provided | Cyanobacteria advisory (harmful blue-green algae) | volume not reported | NJDEP Harmful Algal Bloom Program (Division of Water Monitoring, Standards and Pesticide Control), record a12d4934-c183-4cde-b2f6-9ac54bf0c2f3, updated by the source Jul 4, 2026, 12:00 PM EDT, retrieved 2026-11-02 21:19 UTC · Read the original notice | Read report: Cyanobacteria advisory (harmful blue-green algae), , Jun 30, 2026, 8:43 AM EDT · Map |
Showing the latest 25 records of 38 records. See them all with filters.
All reports in New Jersey by year: 2026 (25 here) · 2025 (13 here)
Wastewater outlets on this water
Outfall: a pipe or outlet where wastewater enters a water body.
No wastewater outlet in our records is linked to this water.
Boat launches
- Hopatcong State Park Boat Launch · Boat ramp
Source: OpenBoatLaunch launch records (public agency data and OpenStreetMap, Open Database License). · Lake Hopatcong on OpenBoatLaunch
Nearby waters
- Jefferson Lake, NJ No current status shown about 9 km away
- Paulins Kill Lake, NJ No current status shown about 19 km away
- Swartswood Lake, NJ No current status shown about 22 km away
- Wallkill River, NJ No current status shown about 26 km away
- Highland Lake, NJ No current status shown about 29 km away
Sources covering this water
- NJDEP · Latest check succeeded · Last successful check: 2026-11-02 21:19 UTC
- Division of Water Monitoring, Standards and Pesticide Control · Latest check succeeded · Last successful check: 2026-11-02 21:19 UTC
38 records linked to this water. Updated .