Piscataqua River

River in New Hampshire · near Dover, Newington, Portsmouth

No current report

At least one source we follow covers this water, and nothing it reports applies right now.

Why this colour: No current report: nothing a covering source reports colours this water now. How long a water stays coloured, and why

Source: ECHO Effluent Charts REST services (per-permit DMR data incl. monthly CSO event counts, duration, volume per outfall), last answered 2026-11-02 11:54 UTC; ECHO NPDES Sewer Overflow and Bypass Event Dataset (eRule Phase 2, current versions), last answered 2026-11-02 11:54 UTC; nh-permittees, last answered 2026-11-02 11:55 UTC. Status computed by DirtyWaterWatch as of 2026-11-02 11:56 UTC.

It is not a finding about the water. Discharges go unreported, reports arrive late, and storm runoff carries bacteria too. Follow posted signs and local health advice.

Rivers are not coloured as a whole: a discharge colours a modeled stretch downstream of its outfall, listed below when there is one.

As of Nov 2, 2026, 6:56 AM EST.

Map

Source: water outlines from OpenBoatLaunch and OpenStreetMap contributors (ODbL); outfalls from EPA ECHO and the state outfall layers; modeled reaches computed by DirtyWaterWatch from USGS NLDI, NHDPlus and the nearest USGS gauge (Jobson 1996); basemap OpenFreeMap and OpenMapTiles.

Outfalls are small brown dots.

Modeled downstream reaches on Piscataqua River

No discharge colours a modeled reach on this water now.

The last 90 days

Last 90 days, hour by hour. Red: advisory in effect; yellow: caution; hatched yellow: unresolved, no end reported; grey: no current report; hatched purple: a source was not updating.

No red or yellow period in this span.

Source: hourly statuses computed by DirtyWaterWatch (pipeline build/status.py) from the events linked above and the rules on the methods page; history as of 2026-11-02 11:56 UTC.

Discharges over the years

Discharge events, last 12 months0Dec 2025 to Nov 2026; partly covered or sparse source

Discharge events per month

0 events, Jan 2022 to Nov 2026.

Combined sewer overflow
Sanitary sewer overflow
Bypass, blended or other
No source
Partly covered or sparse source

No source covers 2022-01 to 2022-04. Some dischargers here report only monthly or yearly totals; those are shown under reported totals, not counted here.

Source: EPA ECHO sewer overflow events. Covered 2022-05-03 to 2026-11-02.

Show table

Discharge events per month
Month	Combined sewer overflow	Sanitary sewer overflow	Bypass, blended or other	Total	Counted from	Coverage
Jan 2022	0	0	0	0		No source
Feb 2022	0	0	0	0		No source
Mar 2022	0	0	0	0		No source
Apr 2022	0	0	0	0		No source
May 2022	0	0	0	0		Partly covered or sparse source
Jun 2022	0	0	0	0		Partly covered or sparse source
Jul 2022	0	0	0	0		Partly covered or sparse source
Aug 2022	0	0	0	0		Partly covered or sparse source
Sep 2022	0	0	0	0		Partly covered or sparse source
Oct 2022	0	0	0	0		Partly covered or sparse source
Nov 2022	0	0	0	0		Partly covered or sparse source
Dec 2022	0	0	0	0		Partly covered or sparse source
Jan 2023	0	0	0	0		Partly covered or sparse source
Feb 2023	0	0	0	0		Partly covered or sparse source
Mar 2023	0	0	0	0		Partly covered or sparse source
Apr 2023	0	0	0	0		Partly covered or sparse source
May 2023	0	0	0	0		Partly covered or sparse source
Jun 2023	0	0	0	0		Partly covered or sparse source
Jul 2023	0	0	0	0		Partly covered or sparse source
Aug 2023	0	0	0	0		Partly covered or sparse source
Sep 2023	0	0	0	0		Partly covered or sparse source
Oct 2023	0	0	0	0		Partly covered or sparse source
Nov 2023	0	0	0	0		Partly covered or sparse source
Dec 2023	0	0	0	0		Partly covered or sparse source
Jan 2024	0	0	0	0		Partly covered or sparse source
Feb 2024	0	0	0	0		Partly covered or sparse source
Mar 2024	0	0	0	0		Partly covered or sparse source
Apr 2024	0	0	0	0		Partly covered or sparse source
May 2024	0	0	0	0		Partly covered or sparse source
Jun 2024	0	0	0	0		Partly covered or sparse source
Jul 2024	0	0	0	0		Partly covered or sparse source
Aug 2024	0	0	0	0		Partly covered or sparse source
Sep 2024	0	0	0	0		Partly covered or sparse source
Oct 2024	0	0	0	0		Partly covered or sparse source
Nov 2024	0	0	0	0		Partly covered or sparse source
Dec 2024	0	0	0	0		Partly covered or sparse source
Jan 2025	0	0	0	0		Partly covered or sparse source
Feb 2025	0	0	0	0		Partly covered or sparse source
Mar 2025	0	0	0	0		Partly covered or sparse source
Apr 2025	0	0	0	0		Partly covered or sparse source
May 2025	0	0	0	0		Partly covered or sparse source
Jun 2025	0	0	0	0		Partly covered or sparse source
Jul 2025	0	0	0	0		Partly covered or sparse source
Aug 2025	0	0	0	0		Partly covered or sparse source
Sep 2025	0	0	0	0		Partly covered or sparse source
Oct 2025	0	0	0	0		Partly covered or sparse source
Nov 2025	0	0	0	0		Partly covered or sparse source
Dec 2025	0	0	0	0		Partly covered or sparse source
Jan 2026	0	0	0	0		Partly covered or sparse source
Feb 2026	0	0	0	0		Partly covered or sparse source
Mar 2026	0	0	0	0		Partly covered or sparse source
Apr 2026	0	0	0	0		Partly covered or sparse source
May 2026	0	0	0	0		Partly covered or sparse source
Jun 2026	0	0	0	0		Partly covered or sparse source
Jul 2026	0	0	0	0		Partly covered or sparse source
Aug 2026	0	0	0	0		Partly covered or sparse source
Sep 2026	0	0	0	0		Partly covered or sparse source
Oct 2026	0	0	0	0		Partly covered or sparse source
Nov 2026	0	0	0	0		Partly covered or sparse source

Reported monthly totals: NH permittee notices (Nashua, Manchester, Portsmouth, Exeter)

Portsmouth publishes monthly CSO volumes per outfall, not events. Source: NH permittee notices (Nashua, Manchester, Portsmouth, Exeter). Covered 2010-01-01 to 2023-08-01.

Reported volume

Gallons per year (monthly figures summed by year).

Show table

Reported volume
Year	Reported volume
2010	21,941,600 gal
2011	1,756,400 gal
2012	856,800 gal
2013	21,600 gal
2014	1,485,800 gal
2015	247,570 gal
2016	432,000 gal
2017	0 gal
2018	1,618,000 gal
2019	993,000 gal
2020	319,000 gal
2021	1,161,000 gal
2022	0 gal
2023	223,000 gal

How these charts are counted

Discharge events are counted once: where a source publishes both public notices and verified reports (MassDEP, Vermont DEC), a discharger's month with any verified report counts its verified reports only, and other months count notices. Revisions are folded into the record they revise, and EPA copies of a state report are not counted twice. Monthly and yearly totals (Maine DEP, EPA discharge monitoring reports, Portsmouth) are shown on their own and never added to the event counts. Hours under advisory follow the map's red rules. A muted band marks periods no source covers: a gap there is missing data, not a quiet month.

EPA ECHO sewer overflow events: 2022-05-03 to now (sparse)

Every event on Piscataqua River

Events placed on Piscataqua River, newest first
Start	End	Discharger	Outfall	Type	Volume	Source	Links
August 2023	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	59,000 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2023-08:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
July 2023	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	24,000 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2023-07:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
January 2023	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	140,000 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2023-01:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
October 2021	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	849,000 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2021-10:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
July 2021	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	312,000 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2021-07:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
June 2020	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	319,000 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2020-06:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
December 2019	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	974,000 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2019-12:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
June 2019	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	19,000 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2019-06:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
September 2018	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	957,000 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2018-09:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
July 2018	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	149,000 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2018-07:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
April 2018	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	512,000 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2018-04:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
October 2016	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	147,000 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2016-10:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
July 2016	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	35,000 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2016-07:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
June 2016	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	52,000 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2016-06:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
January 2016	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	198,000 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2016-01:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
September 2015	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	9,000 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2015-09:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
April 2015	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	238,570 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2015-04:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
December 2014	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	1.49 million gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2014-12:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
September 2013	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	4,600 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2013-09:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
June 2013	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	17,000 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2013-06:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
December 2012	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	254,300 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2012-12:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
August 2012	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	127,900 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2012-08:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
June 2012	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	326,100 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2012-06:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
April 2012	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	148,500 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2012-04:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
October 2011	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	223,400 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2011-10:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
September 2011	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	28,000 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2011-09:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
June 2011	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	26,900 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2011-06:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
March 2011	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	1.48 million gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2011-03:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
November 2010	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	74,200 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2010-11:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
October 2010	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	528,300 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2010-10:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
August 2010	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	919,300 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2010-08:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
July 2010	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	586,900 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2010-07:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
June 2010	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	63,600 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2010-06:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
May 2010	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	240,400 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2010-05:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
April 2010	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	15,200 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2010-04:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
March 2010	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	15.63 million gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2010-03:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
February 2010	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	3.33 million gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2010-02:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list
January 2010	ended, time not reported	City of Portsmouth DPW Wastewater Division	013 Deer Street	Combined sewer overflow	549,000 gal	City of Portsmouth DPW (CSO page, monthly summary table) via nh-permittees, record portsmouth:2010-01:013, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice	record below · Map
Full record (older than 180 days, so no page of its own) This record in the archive list

Outfalls on this water

No outfall in the registry is matched to this water.

Dischargers: City of Portsmouth DPW Wastewater Division (Peirce Island WWTF and 3 CSOs), NH Medium WWTF General Permit facilities (21 POTWs) - SSO/unauthorized discharge web notices.

Launches

Source: OpenBoatLaunch launch records (public agency data and OpenStreetMap, ODbL). · Piscataqua River on OpenBoatLaunch

Sources covering this water

ECHO Effluent Charts REST services (per-permit DMR data incl. monthly CSO event counts, duration, volume per outfall) · updating · last answered Nov 2, 2026, 6:54 AM EST
ECHO NPDES Sewer Overflow and Bypass Event Dataset (eRule Phase 2, current versions) · updating · last answered Nov 2, 2026, 6:54 AM EST
nh-permittees · updating · last answered Nov 2, 2026, 6:55 AM EST

38 events placed on this water in this build.