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Illinois / Waters /

Sangamon River

River in Illinois, past Arrowsmith, Bath, Beardstown, Blue Mound, Bluff Springs, Brown, Capital, Chandlerville, Cheney's Grove, Clear Lake, Condit, Cooper, Crane Creek, Dawson, Decatur, Drummer, East Bend, Fancy Creek, Gardner, Goose Creek, Harristown, Illiopolis, Kilbourne, Lanesville, Long Creek, Lynchburg, Mahomet, Monticello, Mosquito, Mount Auburn, Newcomb, Niantic, Oakley, Rochester, Salt Creek, Sangamon, Sangamon Valley, South Wheatland, Springfield, Whitmore and Willow Branch

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.

Solid dots mark combined sewer outfalls. Ringed dots mark treatment plant outfalls. A yellow ring with a dashed edge means discharge likely or possible: heavy rain, no report received. Square boat markers mark boat launches listed by OpenBoatLaunch. Dashed river stretches are estimates. Larger round markers with a label mark beach and other official advisories nearby.

Check City of Monticello'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). 16.6 in of rain fell in the 24 hours to Nov 6, 2026, 2:00 AM CST at Sangamon County Water Reclamation District's outfalls (NOAA radar estimate).

Source: NOAA National Weather Service, MRMS radar-only rainfall estimate, valid Nov 6, 2026, 2:00 AM CST, retrieved 2026-11-06 08:57 UTC; threshold: site default; rule: How it works, discharge likely or possible. · Updated

Estimated downstream stretches on Sangamon River

none from a report; 11 routes below outlets with a status

No stretch below a reported discharge has a current status here as of Nov 6, 2026, 3:03 AM CST. The routes below wastewater outlets carry the status shown on each.

Estimated routes below wastewater outlets

11 routes below outlets
  • Caution Permit IL0021971, outlet 009 · 40 kilometres estimated · Estimate stops at the 40-kilometre limit
  • Caution Permit IL0021971, outlet 010 · 40 kilometres estimated · Estimate stops at the 40-kilometre limit
  • Caution Permit IL0021971, outlet 011 · 40 kilometres estimated · Estimate stops at the 40-kilometre limit
  • Caution Permit IL0021989, outlet 001 · 40 kilometres estimated · Estimate stops at the 40-kilometre limit
  • Caution Permit IL0021989, outlet 002 · 40 kilometres estimated · Estimate stops at the 40-kilometre limit
  • Caution Permit IL0021989, outlet 003 · 40 kilometres estimated · Estimate stops at the 40-kilometre limit
  • Caution Permit IL0021989, outlet 005 · 40 kilometres estimated · Estimate stops at the 40-kilometre limit
  • Caution Permit IL0021989, outlet 006 · 40 kilometres estimated · Estimate stops at the 40-kilometre limit
  • Caution Permit IL0021989, outlet 013 · 40 kilometres estimated · Estimate stops at the 40-kilometre limit
  • Caution Permit IL0023281, outlet 003 · 15.637 kilometres estimated · Estimate stops at a lake or bay
  • Caution Permit IL0021971 · 37.208 kilometres estimated · Estimate stops here

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: a status resting on a source that could not be checked on schedule.

Source: DirtyWaterWatch calculations using the reports named above and the published status rules. Updated 2026-11-06 09:03 UTC.

Reported discharges over time

  • Discharges affecting the Sangamon River in Illinois, last 12 months11 affecting this stretch: 0 reported on the Sangamon River; 1 arriving from outfalls upstream on the Spring Creek, Sangamon County Water Reclamation DistrictDecember 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 Sangamon River in Illinois, last 12 months2Reported on the Sangamon River: 0 · Arriving from outfalls upstream on the Spring Creek, Sangamon County Water Reclamation District, estimated: 2 (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 Sangamon River in Illinois, last 12 months22Reported on the Sangamon River: 0 · Arriving from outfalls upstream on the Spring Creek, Sangamon County Water Reclamation District, estimated: 22December 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.
  • 2023 season with a discharge or advisory status on the Sangamon River in Illinois0.0%May to October 2023; incomplete source coverageShare 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 Sangamon River in Illinois5Reported on the Sangamon River: 0 · Arriving from outfalls upstream on the Spring Creek, Sangamon County Water Reclamation District, estimated: 1 · Other records (rain-likely and similar): 4last 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.

Reported discharges per month

2 reported discharges, January 2022 to November 2026.

  • Combined sewer overflow
  • Sanitary sewer overflow
  • Treatment bypass, blended or other
  • Incomplete source coverage
Limited records

The U.S. Environmental Protection Agency's sewer overflow records are limited: they hold only what operators file with the agency.

Source: U.S. Environmental Protection Agency sewer overflow records. Records cover May 3, 2022 to November 6, 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
  • Incomplete source coverage
Limited records

The U.S. Environmental Protection Agency's sewer overflow records are limited: they hold only what operators file with the agency.

Source: U.S. Environmental Protection Agency sewer overflow records. Records cover May 3, 2022 to November 6, 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.

  • Incomplete source coverage
Limited records

Source: U.S. Environmental Protection Agency sewer overflow records. Records cover May 3, 2022 to November 6, 2026.

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Reported discharges per year, 2000 to 2026

2 reported discharges, 2000 to 2026.

  • Combined sewer overflow
  • Sanitary sewer overflow
  • Treatment bypass, blended or other
  • Incomplete source coverage
Limited records

The U.S. Environmental Protection Agency's sewer overflow records are limited: they hold only what operators file with the agency.

Source: U.S. Environmental Protection Agency sewer overflow records. Records cover May 3, 2022 to November 6, 2026.

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Reported volume per year

Gallons (axis: K thousand, M million), summed from the 2 reports that gave a volume as a number.

  • Incomplete source coverage
Limited records

Source: U.S. Environmental Protection Agency sewer overflow records. Records cover May 3, 2022 to November 6, 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
  • Incomplete source coverage
Limited records

Source: U.S. Environmental Protection Agency sewer overflow records. Records cover May 3, 2022 to November 6, 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
  • Season with incomplete source coverage

Seasons with incomplete source coverage: 2023. The share is of the hours a source covered.

Source: U.S. Environmental Protection Agency sewer overflow records. Records cover May 3, 2022 to November 6, 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: U.S. Environmental Protection Agency sewer overflow records. Records cover May 3, 2022 to November 6, 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)
  • il-mwrd-lake-michigan-reversals: records from March 4, 1985 to July 3, 2023

Reports linked to Sangamon River

Reports linked to Sangamon River, newest first
WhenReportStatus
to 3:55 PM CDTSanitary District Of Decatur · SSO · 35 gallons report · notice · mapended

Sources: EPA ECHO Sewer Overflow and Bypass Event report (reported to regulators), retrieved 2026-11-06 08:38 UTC. A report's record id and times show when you hover or focus its "report" link.

Download these reports as CSV

All reports in Illinois by year: 2025 (1 here)

Wastewater outlets on this water

Outfall: a pipe or outlet where wastewater enters a water body.

Combined sewer outfalls

17 outfalls · discharge possible now at 17

Discharge possible: heavy rain, no report received at 17 outfalls now: radar rainfall has reached the operator's threshold and no discharge report has arrived (NOAA radar estimate).

Showing 12 of 17.

Source: U.S. Environmental Protection Agency (EPA) national combined sewer outfall inventory (ECHO) and state outfall layers. Open or closed as EPA's inventory lists it. DirtyWaterWatch links outlets to waters using permit numbers, locations and names.

Treatment plant outfalls

18 outfalls

Showing 12 of 18.

Source: U.S. Environmental Protection Agency (EPA) permit records (ICIS-NPDES permitted features): where a treatment plant’s permitted discharge leaves. No national source says whether a plant outfall is open or closed.

Sewer operators listed for this water: City of Monticello, City of Petersburg, Sangamon County Water Rec District (Spring Creek STP), Sangamon Valley Public Water District, Sanitary District Of Decatur, Village of Harristown, Village of Mahomet, Village of Riverton.

Boat launches

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

Nearby waters

Sources covering this water

1 record linked to this water. Updated .