Where is Willamette Slough?

Willamette Slough is a lake in Marion County, Oregon. Its water-quality measurements are published by Oregon DEQ and shown on this page as reported.

Willamette Slough

Marion County, Oregon55 acresView map Directions

No nutrient or algae sampling on record from Oregon DEQ for this lake.

Area

55 acres

Surface area

Impaired · Oxygen depletion (low DO)

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Willamette Slough in Marion County, Oregon has water-quality measurements published by Oregon DEQ, shown here as reported. Surface area: 55 acres.

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Willamette Slough is a 55-acre lake in Marion County, Oregon.

Source: EPA Water Quality Portal sampling records, Oregon DEQ. Methodology: how these readings are compared.

Swimming conditions

No reading

Not rated

Nutrient and algae readings are not a swimming clearance. Willamette Slough is listed impaired under Clean Water Act §303(d) (IR 5) for oxygen depletion (low DO), temperature. Check local advisories before you swim.

Whether Willamette Slough is safe to swim in today is a call for the Oregon Department of Environmental Quality and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.

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Water quality measurements for Willamette Slough

These are the measurements Oregon DEQ publishes for Willamette Slough, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.

No clarity data. TSI undefined.

Ask about Willamette Slough

Answers come straight from the public measurements and survey records on this page.

Lake Details

Surface area

55 acres

No bathymetric survey has been published for Willamette Slough, so its depth is not documented here.

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Stays near Willamette Slough

Compare lakeside cabins, hotels, and vacation rentals near Willamette Slough in Marion County, Oregon — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.

Top-rated places to stay near Willamette Slough

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Fishing Willamette Slough

→ Willamette Slough fishing regulations (limits, seasons, special rules)

EPA Impairment Status

Willamette Slough is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).

Causes of impairment

Oxygen depletion (low DO)Temperature

Designated uses not supporting: Aquatic life.

Source: EPA ATTAINS assessment unit OR_LK_1709000703_02_100792 · Official waterbody report

Nearby Lakes in Marion County

Stone Quarry Lake2.1 miView →Clear Lake6.9 miView →Mission Lake10.3 miView →Horseshoe Lake19.1 miView →McKay Reservoir—View →Mission Creek Reservoir—View →

Frequently asked questions about Willamette Slough

Where is Willamette Slough?: Willamette Slough is a lake in Marion County, Oregon. Its water-quality measurements are published by Oregon DEQ and shown on this page as reported.
What is the water quality of Willamette Slough?: Willamette Slough in Marion County, Oregon has water-quality measurements published by Oregon DEQ, shown here as reported. Surface area: 55 acres.
Is Willamette Slough safe to swim in?: Nutrient and algae readings are not a swimming clearance. Willamette Slough is listed impaired under Clean Water Act §303(d) (IR 5) for oxygen depletion (low DO), temperature. Check local advisories before you swim.