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Maryland / Waters /

Gwynns Falls

Stream in Maryland, past Baltimore, Lochearn, Owings Mills, Pikesville, Randallstown, Reisterstown and Woodlawn

Current status

Caution

Caution applies after a recent discharge, when a report leaves its status unclear, or during a rainfall advisory. The report explains which rule applies. This status since . Why this status, and its source

This status counts every report affecting this water, including discharges arriving from upstream.

This badge describes the water outline. Check the downstream stretches on the map and below for discharge statuses.

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.

Dashed river stretches are estimates.

Check Baltimore City Department of Public Works (separate sanitary system; Back River and Patapsco WWTPs)'s notices · Bookmark this water page and check it before each trip · Report a missing notice or error

About this status

Caution: discharge record with unclear status; caution for 14 days, then shown as unconfirmed (site rule)

Source: Baltimore City Department of Public Works (Sewer Overflow Map) via Baltimore City DPW Sewer Overflow Map (SSO_Points2 map service), record 25967, the source gives no report time, retrieved 2026-11-03 08:17 UTC · Original notice · Updated

Reports behind this status

Sanitary sewer overflow (SSO): sewage spills from a sewer meant to carry sewage separately from rainwater.

Reports behind the status of Gwynns Falls, newest first
WhenReportStatus
Baltimore City DPW · 619 Nottingham Rd · SSO · 5 gallons report · notice · mapto Nov 15, 3:50 PM

Sources: Baltimore City DPW Sewer Overflow Map (SSO_Points2 map service), retrieved 2026-11-03 08:17 UTC. A report's record id and times show when you hover or focus its "report" link.

Estimated downstream stretches on Gwynns Falls

Estimated downstream stretch — not checked by water sampling. Estimated by DirtyWaterWatch using U.S. Geological Survey river maps and flow measurements; not an official advisory area.

Estimated routes below wastewater outlets

Source: DirtyWaterWatch estimates using U.S. Geological Survey river maps and flow measurements. The estimate stops at tidal water, the first lake or the distance limit.

The last 90 days

Last 90 days, hour by hour. Red: discharge or advisory reported. Amber: caution. Hatched amber: end not confirmed. Grey: no current status on the water outline. Purple hatching: source update overdue.
  • Caution: to the latest update
    1 report: Baltimore City DPW 1
    Show records

    The records are also in the report table on this page.

  • Caution: to
    1 report: Baltimore City DPW 1
    Show records

    The records are also in the report table on this page.

  • Discharge or advisory reported: to
    1 report: Baltimore City DPW 1
    Show records

    The records are also in the report table on this page.

  • Caution: to
    1 report: Baltimore City DPW 1
    Show records

    The records are also in the report table on this page.

  • Discharge or advisory reported: to
    1 report: Baltimore City DPW 1
    Show records

    The records are also in the report table on this page.

  • Caution: to
    2 reports: Baltimore City DPW 2
    Show records

    The records are also in the report table on this page.

  • Discharge or advisory reported: to
    2 reports: Baltimore City DPW 2
    Show records

    The records are also in the report table on this page.

  • End not confirmed: to
    1 report: Baltimore City DPW 1
    Show records

    The records are also in the report table on this page.

  • Caution: to
    2 reports: Baltimore City DPW 2
    Show records

    The records are also in the report table on this page.

  • Discharge or advisory reported: to
    1 report: Baltimore City DPW 1
    Show records

    The records are also in the report table on this page.

  • Caution: to
    2 reports: Baltimore City DPW 1, Baltimore County DPW 1
    Show records

    The records are also in the report table on this page.

  • Discharge or advisory reported: to
    1 report: Baltimore County DPW 1
    Show records

    The records are also in the report table on this page.

  • Caution: to
    2 reports: Baltimore City DPW 1, Baltimore County DPW 1
    Show records

    The records are also in the report table on this page.

  • Discharge or advisory reported: to
    2 reports: Baltimore City DPW 1, Baltimore County DPW 1
    Show records

    The records are also in the report table on this page.

  • End not confirmed: to
    1 report: Baltimore City DPW 1
    Show records

    The records are also in the report table on this page.

  • Caution: to
    1 report: Baltimore City DPW 1
    Show records

    The records are also in the report table on this page.

  • Discharge or advisory reported: to
    1 report: Baltimore City DPW 1
    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 2026-11-03 08:50 UTC.

Reported discharges over time

  • Discharges affecting the Gwynns Falls in Maryland, last 12 months2929 affecting this stretch: 28 reported in Maryland, 1 arriving from upstream outfalls in MarylandDecember 2025 to November 2026Verified reports where available, else notices; revisions and duplicates counted once. Arriving discharges are estimated from modeled downstream reaches.
  • Days with a discharge affecting the Gwynns Falls in Maryland, last 12 months48Reported on the Gwynns Falls in Maryland: 47 · Arriving from outfalls upstream in Maryland, estimated: 1December 2025 to November 2026A day counts once however many discharges were under way on it. Verified reports where available, else notices; revisions and duplicates counted once.
  • Hours with a discharge or advisory status on the Gwynns Falls in Maryland, last 12 months619Reported on the Gwynns Falls in Maryland: 619 · Arriving from outfalls upstream in Maryland, 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 Gwynns Falls in Maryland9.2%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 Gwynns Falls in Maryland12Reported on the Gwynns Falls in Maryland: 11 · Arriving from outfalls upstream in Maryland, estimated: 1last 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.

Combined sewer overflow (CSO): sewage mixed with rainwater spills from a shared sewer system. Sanitary sewer overflow (SSO): sewage spills from a sewer meant to carry sewage separately from rainwater. Treatment bypass: wastewater skips one or more treatment steps. Blended discharge: wastewater that skipped some treatment is mixed with treated wastewater. Outfall: a pipe or outlet where wastewater enters a water body.

Reported discharges per month

155 reported discharges, January 2022 to November 2026.

  • Combined sewer overflow
  • Sanitary sewer overflow
  • Treatment bypass, blended or other
  • No tracked source for this period
  • Incomplete source coverage
No tracked source

No tracked source covers January 2022 to December 2022.

Sources: md-baltimore-sso; md-mde-overflows. Records cover January 4, 2023 to November 3, 2026.

Show table

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

No tracked source covers January 2022 to December 2022. 4 discharge reports have no end time and are not marked ongoing; under DirtyWaterWatch rules they show caution, not a discharge or advisory status, and add no hours here.

Sources: md-baltimore-sso; md-mde-overflows. Records cover January 4, 2023 to November 3, 2026.

Show table

Days with a reported discharge per month

A day counts when any counted discharge was under way on it, from its start to its reported end in Eastern Time; a report with no end counts its start day.

  • No tracked source for this period
  • Incomplete source coverage
No tracked source

No tracked source covers January 2022 to December 2022.

Sources: md-baltimore-sso; md-mde-overflows. Records cover January 4, 2023 to November 3, 2026.

Show table

Reported volume per year

Gallons (axis: K thousand, M million), summed from the 155 reports that gave a volume as a number.

  • Incomplete source coverage
Limited records

Sources: md-baltimore-sso; md-mde-overflows. Records cover January 4, 2023 to November 3, 2026.

Show table

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
Limited records

4 discharge reports have no end time and are not marked ongoing; under DirtyWaterWatch rules they show caution, not a discharge or advisory status, and add no hours here.

Sources: md-baltimore-sso; md-mde-overflows. Records cover January 4, 2023 to November 3, 2026.

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Share of the May to October season with a discharge or advisory status

Share of the hours from May 1 to October 31 with a discharge or advisory status under DirtyWaterWatch rules.

  • Discharge or advisory reported

4 discharge reports have no end time and are not marked ongoing; under DirtyWaterWatch rules they show caution, not a discharge or advisory status, and add no hours here.

Sources: md-baltimore-sso; md-mde-overflows. Records cover January 4, 2023 to November 3, 2026.

Show table

Reported discharges by calendar month, all years

Every counted discharge report, by the calendar month it began.

Months are summed over every year a tracked source covers; the table gives the number of years behind each month.

Sources: md-baltimore-sso; md-mde-overflows. Records cover January 4, 2023 to November 3, 2026.

Show table

Reported discharges by wastewater outlet

Wastewater outlets with the most tracked discharge records: 10 of 132, all years. Counts depend on reporting coverage and do not measure legal compliance or harm.

Sources: md-baltimore-sso; md-mde-overflows. Records cover January 4, 2023 to November 3, 2026.

Show table
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.

  • md-baltimore-sso: records from June 23, 2024 to the latest update
  • md-mde-overflows: records from January 4, 2023 to the latest update

Reports linked to Gwynns Falls

Sanitary sewer overflow (SSO): sewage spills from a sewer meant to carry sewage separately from rainwater.

Reports linked to Gwynns Falls, newest first
WhenReportStatus
to 1:30 PMBaltimore City DPW · 2801 Frederick Ave · SSO · 6,000 gallons in all mapended
to 11:06 PMBaltimore City DPW · 1510 Mosher St · SSO · 401 gallons report · notice · mapended
to Oct 14, 9:54 AMBaltimore City DPW · N Hilton St & Edmondson Ave · SSO · 15,176 gallons in all mapended
to 3:41 PMBaltimore City DPW · N Rosedale St & Carlisle Ave · SSO · 198 gallons in all mapended
Baltimore City DPW · 2508 Queen Anne Rd · SSO · 2 gallons report · notice · mapreported
to Sep 6, 8:00 AMBaltimore County DPW · 2620 Gwyndale Ave · SSO · 40 gallons report · notice · mapended
to 11:30 AMBaltimore County DPW · 6800 Townbrook Drive · SSO · 200 gallons report · notice · mapended
to Aug 31, 6:30 PMBaltimore City DPW · 2300 Pickwick Rd · SSO · 7,025 gallons report · notice · mapended
to Aug 7, 11:15 AMBaltimore City DPW · 1500 Washington Blvd · SSO · 1.62 million gallons in all mapended
Baltimore City DPW · 2212 Russell St · SSO · 10 gallons report · notice · mapreported
to 1:00 PMBaltimore City DPW · 4755 Melbourne Road · SSO (earlier version) · 600 gallons report · notice · mapended
to May 29, 10:43 PMBaltimore City DPW · 1946 Hollands Ferry Rd · SSO · 5,813 gallons report · notice · mapended
to 3:46 PMBaltimore City DPW · 3615 West Forest Park Ave · SSO · 1,410 gallons report · notice · mapended
to 10:30 AMBaltimore County DPW · 7512 Remoor Rd · SSO · 100 gallons report · notice · mapended
to 6:40 PMBaltimore City DPW · 1600 Morris Road · SSO · 2,150 gallons report · notice · mapended
to 10:01 AMBaltimore City DPW · 4221 Greenspring Lane · SSO · 5 gallons report · notice · mapended
to Mar 4, 8:00 AMBaltimore County DPW · 6825 Campfield Rd · SSO · 2,500 gallons report · notice · mapended
to 5:44 PMBaltimore City DPW · 3439 Edmondson Ave · SSO · 439 gallons report · notice · mapended
to Feb 4, 2:15 PMBaltimore City DPW · 2402 Harriet Ave · SSO · 7,440 gallons report · notice · mapended
to 8:00 PMBaltimore City DPW · 2301 Washington Blvd · SSO · 11,250 gallons report · notice · mapended
to 8:05 AMBaltimore City DPW · 1055 Ellicott Drive · SSO · 0 gallons report · notice · mapended

Sources: Baltimore City DPW Sewer Overflow Map (SSO_Points2 map service), retrieved 2026-11-03 08:17 UTC; MDE Reported Sewer Overflows (New for 2023), Maryland Open Data Portal (Socrata stgj-u72u), retrieved 2026-11-03 08:17 UTC. A report's record id and times show when you hover or focus its "report" link.

Download these reports as CSV

Showing the latest 25 records of 165 records.See them all with filters.

All reports in Maryland by year: 2026 (24 here) · 2025 (58 here) · 2024 (49 here) · 2023 (34 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.

Sewer operators listed for this water: Baltimore City Department of Public Works (separate sanitary system; Back River and Patapsco WWTPs), Baltimore County Department of Public Works and Transportation (sewer collection; flows to City plants).

Boat launches

No public boat launch is listed in our records for this water.

Nearby waters

Sources covering this water

165 records linked to this water. Updated .