River IL

Saint Johns Ditch

Illinois • 37.0950, -89.5422

Reviewed mapped path Updated Dec 30, 2025

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USGS and NOAA data is for informational purposes. Source notes

Length

38 mi

62 km

Elevation

369′ → 273′

96 ft drop

Stream Order

Medium River

Slope

0.05%

2.5 ft/mi

Drainage

262 mi²

679 km²

Avg Flow

-- cfs

1.1 mph velocity

Path to Mouth

951 mi

1,531 km to ocean

Classification

Tributary

Mid-reach

Elevation Profile

Water Quality

Data from EPA Water Quality Portal (USGS, EPA, state agencies).

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Data from USGS & NOAA for informational purposes only. Read source and safety notes

Rain Radar