Where is Willow Lake?

Willow Lake is a lake in Contra Costa County, California. Its water-quality measurements are published by SWRCB and shown on this page as reported.

Are there boat ramps on Willow Lake?

Willow Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Discovery Bay Yacht Harbor.

Can I fish at Willow Lake?

Willow Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by California's fish and wildlife agency, so check its current regulations before you go.

Willow Lake

Contra Costa County, California89 acresView map Directions

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

Area

89 acres

Surface area

Impaired · Mercury

See the measurements Directions Where to stay

Willow Lake in Contra Costa County, California has water-quality measurements published by SWRCB, shown here as reported. Surface area: 89 acres.

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Willow Lake is a 89-acre lake in Contra Costa County, California. Public access is available with 1 public boat landing.

Source: EPA Water Quality Portal sampling records, your state environmental agency. Methodology: how these readings are compared.

What Willow Lake is good for

From access and monitoring records, not editorial picks.

Boat launch1 documented ramp

Swimming conditions

No reading

Not rated

Nutrient and algae readings are not a swimming clearance. Willow Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.

Whether Willow Lake is safe to swim in today is a call for the California State Water Resources Control Board and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.

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Water quality measurements for Willow Lake

These are the measurements SWRCB publishes for Willow Lake, 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 Willow Lake

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

Lake Details

Surface area

89 acres

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

Recreation & Access

Boat Landings

Discovery Bay Yacht HarborSemi-private

Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps

Stays via Stay22

Stays near Willow Lake

Compare lakeside cabins, hotels, and vacation rentals near Willow Lake in Contra Costa County, California — 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 Willow Lake

Prices for Oct 16–18, 4 adults. Change dates on the map below.

Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.

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Fishing Willow Lake

→ Willow Lake fishing regulations (limits, seasons, special rules)

EPA Impairment Status

Willow Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).

Causes of impairment

Mercury

Designated uses not supporting: Fish consumption.

Source: EPA ATTAINS assessment unit CAL5440000020091215013109 · Official waterbody report

Nearby Lakes in Contra Costa County

Clifton Court Forebay4.9 miView →Holland Tract South Pond7.4 miView →Holland Tract Middle Pond7.4 miView →Holland Tract North Pond8.2 miView →Marsh Creek Reservoir7.1 miView →Webb Tract East Pond—View →

Frequently asked questions about Willow Lake

Where is Willow Lake?: Willow Lake is a lake in Contra Costa County, California. Its water-quality measurements are published by SWRCB and shown on this page as reported.
What is the water quality of Willow Lake?: Willow Lake in Contra Costa County, California has water-quality measurements published by SWRCB, shown here as reported. Surface area: 89 acres.
Is Willow Lake safe to swim in?: Nutrient and algae readings are not a swimming clearance. Willow Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.
Are there boat ramps on Willow Lake?: Willow Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Discovery Bay Yacht Harbor.
Can I fish at Willow Lake?: Willow Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by California's fish and wildlife agency, so check its current regulations before you go.