DirtyWaterWatch Public waters. Public record.

Michigan / Waters /

Shiawassee River

River in Michigan, past Bancroft, Chesaning, Holly, Linden and New Haven

Current status

Discharge possible: heavy rain, no report received

Radar shows that recent rain at a combined sewer system's outlets has reached the amount set for that system, and its operator has not reported a discharge. It reads "discharge likely" where the amount is the one at which that system has discharged before, or a rain trigger its state publishes, and "discharge possible" where only this site's default of 0.1 inch applies. This is an estimate, not a report. This status since . Why this status, and its source

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.

Square boat markers mark boat launches listed by OpenBoatLaunch. Dashed river stretches are estimates.

Check City of Durand's notices · Bookmark this water page and check it before each trip · Report a missing notice or error

About this status

Discharge possible: heavy rain, no report received: heavy rain at a sewer operator's outlets reached this site's default amount, and no report received; shown for 48 hours after the rain (site rule). 1.7 in of rain fell in the 24 hours to Nov 4, 2026, 7:00 PM EST at Saginaw Charter Township's outfalls (NOAA radar estimate).

Source: NOAA National Weather Service, MRMS radar-only rainfall estimate, valid Nov 4, 2026, 7:00 PM EST, retrieved 2026-11-05 01:19 UTC; threshold: site default; rule: How it works, discharge likely or possible. · Updated

Estimated downstream stretches on Shiawassee River

none from a report; 1 route below outlets with a status

No stretch below a reported discharge has a current status here as of Nov 4, 2026, 8:25 PM EST. The routes below wastewater outlets carry the status shown on each.

Estimated routes below wastewater outlets

1 route below outlets
  • Caution Permit MI0023973, outlet 003 · 40 kilometres estimated · Estimate stops at the 40-kilometre limit

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. Plum: algal bloom advisory. Red or amber with a light line inside: beach advisory or caution. Dotted: monthly report (days with discharge, dates not given). Grey: no current status on the water outline. Purple hatching: source update overdue.
  • Discharge likely or possible: heavy rain, no report received: to the latest update
    Radar estimate, no report received: heavy rain at the outlets of Saginaw Charter Township

Source: DirtyWaterWatch calculations using the reports named above and the published status rules. Updated 2026-11-05 01:25 UTC.

Reported discharges over time

  • Discharges affecting the Shiawassee River in Michigan, last 12 months1616 affecting this stretch: 10 reported on the Shiawassee River; 6 arriving from outfalls upstream on the Tittabawassee River, Saginaw Charter TownshipDecember 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 Shiawassee River in Michigan, last 12 months44Reported on the Shiawassee River: 18 · Arriving from outfalls upstream on the Tittabawassee River, Saginaw Charter Township, estimated: 32 (counted apart; together they need not equal the total)December 2025 to November 2026A day counts once however many discharges were under way on it.
  • Hours with a discharge or advisory status on the Shiawassee River in Michigan, last 12 months1,066Reported on the Shiawassee River: 420 · Arriving from outfalls upstream on the Tittabawassee River, Saginaw Charter Township, estimated: 868 (counted apart; together they need not equal the total)December 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 Shiawassee River in Michigan8.0%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 Shiawassee River in Michigan1Reported on the Shiawassee River: 0 · Arriving from outfalls upstream on the Tittabawassee River, Saginaw Charter Township, estimated: 0 · Other records (rain-likely and similar): 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

57 reported discharges, January 2022 to November 2026.

  • Combined sewer overflow
  • Sanitary sewer overflow
  • Treatment bypass, blended or other

Source: mi-egle-mienviro-cso-sso-list. Records cover January 1, 2022 to November 4, 2026.

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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

12 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. 2 discharges reported to last more than 31 days are counted as 31 days.

Source: mi-egle-mienviro-cso-sso-list. Records cover January 1, 2001 to November 4, 2026.

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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.

Source: mi-egle-mienviro-cso-sso-list. Records cover January 1, 2022 to November 4, 2026.

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Reported discharges per year, 2001 to 2026

291 reported discharges, 2001 to 2026.

  • Combined sewer overflow
  • Sanitary sewer overflow
  • Treatment bypass, blended or other

Source: mi-egle-mienviro-cso-sso-list. Records cover January 1, 2001 to November 4, 2026.

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Reported volume per year

Gallons (axis: K thousand, M million), summed from the 273 reports that gave a volume as a number (18 did not).

18 of 291 discharge reports gave no volume as a number; only numbers are summed.

Source: mi-egle-mienviro-cso-sso-list. Records cover January 1, 2001 to November 4, 2026.

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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

12 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. 2 discharges reported to last more than 31 days are counted as 31 days.

Source: mi-egle-mienviro-cso-sso-list. Records cover January 1, 2001 to November 4, 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

12 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. 2 discharges reported to last more than 31 days are counted as 31 days.

Source: mi-egle-mienviro-cso-sso-list. Records cover January 1, 2001 to November 4, 2026.

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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.

Source: mi-egle-mienviro-cso-sso-list. Records cover January 1, 2001 to November 4, 2026.

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Reported discharges by wastewater outlet

Wastewater outlets with the most tracked discharge records: 10 of 66, all years. Counts depend on reporting coverage and do not measure legal compliance or harm.

Source: mi-egle-mienviro-cso-sso-list. Records cover January 1, 2001 to November 4, 2026.

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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.

  • U.S. Environmental Protection Agency sewer overflow records: records from May 3, 2022 to the latest update (limited records)
  • mi-egle-mienviro-cso-sso-list: records from January 1, 2001 to the latest update

Reports linked to Shiawassee River

Reports linked to Shiawassee River, newest first
WhenReportStatus
to May 20, 7:30 AMGenesee County Division of Water & Waste Services · Genesee Co #7-Argentine WWSL Outfall 001 - Genesee Co #7-Argentine WWSL Outfall 001 which is the typical point source discharge for the facility. · Bypass · 11.52 million gallons report · notice · mapended
to 11:00 AMCity of Durand · Holly Drain - The holly drain is located adjacent to the wastewater treatment plant · SSO · 3,000 gallons report · notice · mapended
to Apr 8, 8:00 AMCity Of Corunna · Corunna EQ Tank - [house number removed] Pine Street · SSO · 111,300 gallons report · notice · mapended
City Of Corunna · [house number removed] Pine Street · SSO · volume not reported report · notice · mapongoing
City of Durand · Holly Drain - The Holly Drain is located next to the wwtp propert · SSO · 2.9 million gallons report · notice · mapended
to 11:10 PMCity of Owosso · Manhole B - Manhole on south Shiawassee River bank about 100 ft east of Union St. · SSO · 134,600 gallons in all mapended
City of Durand · The drain is located next to the plant · SSO · volume not reported report · notice · mapongoing
to Mar 7, 2:45 AMCity of Durand · WWTP outfall to Holly Drain - Holly Drain · SSO · 226,000 gallons report · notice · mapended
to 11:00 PMDurand WWTP · Durand WWTP overflow - Overflow to Holly Drain · SSO · 112,000 gallons report · notice · mapended
to Dec 28 ’25, 11:00 PMCity of Durand · WWTP overflow into Holly Drain · SSO · 110,000 gallons report · notice · mapended
to 10:30 PMVillage of Chesaning · Manhole · SSO (earlier version) · 200 gallons in all mapended
to Nov 12 ’24, 10:00 AMCity of Owosso · Storm water outfall - Storm water outfall south bank of Shiawassee River; opposite Dewey St on north bank · SSO · 2,000 gallons report · notice · mapended
to Aug 25 ’23, 12:05 AMCity of Owosso · Manhole B - Manhole on south Shiawassee River bank about 100 ft east of Union St. · SSO · 1,800 gallons report · notice · mapended
to Aug 25 ’23, 12:30 AMCity of Owosso · Manhole A - Manhole on north Shiawassee River bank, just west of M-52 street bridge · SSO · 8,000 gallons report · notice · mapended
to 2:15 AMGenesee County Division of Water & Waste Services · Storm Outfall A - Storm Line to the Shiawassee River · Bypass · 1,000 gallons report · notice · mapended
to 4:18 AMCity of Durand · Holly Drain - County drain adjacent to the wastewater plant · Bypass · 72,000 gallons report · notice · mapended
to Jul 13 ’23, 3:00 AMCity of Owosso · Manhole B - Manhole on south Shiawassee River bank about 100 ft east of Union St. · SSO · 9,800 gallons in all mapended
to 3:15 PMCity of Owosso · Manhole B - Manhole on south Shiawassee River bank about 100 ft east of Union St. · SSO · 7,700 gallons report · notice · mapended
to 11:00 PMCity of Owosso · Manhole A - Manhole on north Shiawassee River bank, just west of M-52 street bridge · SSO · 52,300 gallons report · notice · mapended
to May 4 ’22, 8:00 PMVillage of Byron · Washington Street Liftstation - Manhole overflow due to liftstation malfunction · SSO · 30,000 gallons report · notice · mapended
Village of Chesaning · chapman lift station - wet well · SSO · 84,000 gallons report · notice · mapended
to 11:00 PMCity of Owosso · Manhole A - Manhole on north Shiawassee River bank, just west of M-52 street bridge · SSO · 16,000 gallons report · notice · mapended

Sources: EGLE MiEnviro CSO/SSO List, retrieved 2026-11-05 01:07 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 156 records.See them all with filters.

All reports in Michigan by year: 2026 (9 here) · 2025 (4 here) · 2024 (1 here) · 2023 (8 here) · 2022 (2 here) · 2021 (2 here) · 2020 (11 here) · 2019 (4 here) · 2018 (5 here) · 2017 (2 here) · 2016 (1 here) · 2014 (8 here) · 2013 (14 here) · 2012 (1 here) · 2011 (10 here) · 2010 (1 here) · 2009 (4 here) · 2008 (4 here) · 2007 (4 here) · 2006 (12 here) · 2005 (4 here) · 2004 (9 here) · 2003 (6 here) · 2002 (13 here) · 2001 (17 here)

Wastewater outlets on this water

No wastewater outlet in our records is linked to this water.

Sewer operators listed for this water: City of Durand, City of Owosso, Genesee County Division of Water & Waste Services, Village of Chesaning, Village of Holly, Village of Byron, Lake Leslie Sanitary System Drain Drainage District.

Boat launches

Source: OpenBoatLaunch launch records (public agency data and OpenStreetMap, Open Database License). · Shiawassee River on OpenBoatLaunch

Nearby waters

Sources covering this water

154 records linked to this water, besides 2 earlier versions or duplicates. Updated .