Flood Watch
2026-08-06T10:00:00-05:00

* WHAT...Flash flooding caused by excessive rainfall continues to be possible. * WHERE...A portion of southwest Illinois, including the following areas, Greene IL, Jersey IL, Madison IL, Monroe IL and Saint Clair IL. * WHEN...From 10 PM CDT this evening through Thursday morning. * IMPACTS...Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. * ADDITIONAL DETAILS... - Thunderstorms with high rainfall rates are expected to develop and track repeatedly over similar locations late this evening into Thursday morning, which will likely lead to areas of flash flooding.

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Illinois

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Flood Watch
Until 2026-08-06T04:45:00-05:00 • National Weather Service
* WHAT...Flash flooding caused by excessive rainfall continues to be possible. * WHERE...A portion of southwest Illinois, including the following areas, Greene IL, Jersey IL, Madison IL, Monroe IL and Saint Clair IL. * WHEN...From 10 PM CDT this evening through Thursday morning. * IMPACTS...Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. * ADDITIONAL DETAILS... - Thunderstorms with high rainfall rates are expected to develop and track repeatedly over similar locations late this evening into Thursday morning, which will likely lead to areas of flash flooding.

CAHOKIA CREEK AT EDWARDSVILLE, IL

Realtime Data • Report • Conditions

45

Discharge (cfs)

3.6

Gauge Height (ft)

USGS 05587900

Streamflow discharge was last observed at 45 cfs, and a gauge height of 3.60 feet. With the % decrease since yesterday, the streamflow average over the past 10 days is 160 .

Weather today, Tomorrow,

The creek is fed by various small streams and runoff from urban and agricultural areas. There are no major dams on the creek, but there are several smaller ones used for flood control. The flow of the creek varies seasonally, with highest flows typically occurring in the spring due to snowmelt and spring rain. Interestingly, the Cahokia Creek is named after the Cahokia Mounds, a pre-Columbian Native American settlement located near the creek.

August 5, 2026

Elevation	456.0 ft
Last Updated
Gage height, ft	3.6 ft
Streamflow, ft³/s	45.0 ft3/s
Percent of Normal	281%
Year Over Year Average	16 cfs
24hr Flow Prediction	cfs
Maximum Recorded	9,760 cfs
Geolocation	38.82, -89.97

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Cahokia Creek At Edwardsville, Il Realtime Data

CAHOKIA CREEK AT EDWARDSVILLE, IL

Realtime Data • Report • Conditions

45

Discharge (cfs)

3.6

Gauge Height (ft)

August 5, 2026

Seasonal Comparison

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Cahokia Creek At Edwardsville, Il Realtime Data

CAHOKIA CREEK AT EDWARDSVILLE, IL

Realtime Data • Report • Conditions

45

Discharge (cfs)

3.6

Gauge Height (ft)

August 5, 2026

Seasonal Comparison

Oceanic Nino Index

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