Where is Foster Reservoir?

Foster Reservoir is a lake in Franklin County, Idaho. Its water-quality measurements are published by Idaho DEQ and shown on this page as reported.

Are there boat ramps on Foster Reservoir?

Foster Reservoir has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Foster Reservoir. Public access is listed as yes.

Can I fish at Foster Reservoir?

Foster Reservoir 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 Idaho's fish and wildlife agency, so check its current regulations before you go.

Foster Reservoir

Franklin County, Idaho66 acresView map Directions

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

Area

66 acres

Surface area

Shoreline

3.2 mi

Measured length

Impaired · Mercury
Public access

See the measurements Directions Where to stay

Foster Reservoir in Franklin County, Idaho has water-quality measurements published by Idaho DEQ, shown here as reported. Surface area: 66 acres.

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Foster Reservoir is a 66-acre lake in Franklin County, Idaho. Limited fish-species data available. Public access is available with 1 public boat landing.

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

What Foster Reservoir is good for

From access and monitoring records, not editorial picks.

Boat launch1 documented ramp

Swimming conditions

No reading

Recreation use not supported

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

Whether Foster Reservoir is safe to swim in today is a call for the Idaho 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 Foster Reservoir

These are the measurements Idaho DEQ publishes for Foster Reservoir, 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 Foster Reservoir

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

Lake Details

Surface area

66 acres

Shoreline

3.2 mi

Public access

Yes

Listed by Idaho DEQ

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

Recreation & Access

Boat Landings

Yes

Public Access

Foster ReservoirPublic

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

Stays via Stay22

Stays near Foster Reservoir

Compare lakeside cabins, hotels, and vacation rentals near Foster Reservoir in Franklin County, Idaho — 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 Foster Reservoir

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Fishing Foster Reservoir

→ Foster Reservoir fishing regulations (limits, seasons, special rules)

EPA Impairment Status

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

Causes of impairment

Mercury

Designated uses not supporting: Aquatic life, Recreation.

Source: EPA ATTAINS assessment unit ID16010202BR005_01L · Official waterbody report

Nearby Lakes in Franklin County

Lamont Reservoir1.7 miView →Johnson Reservoir2 miView →Glendale Reservoir2.1 miView →Winder Reservoir4.2 miView →Strongarm Reservoir Number One7.8 miView →Twin Lakes Reservoir8.1 miView →

Frequently asked questions about Foster Reservoir

Where is Foster Reservoir?: Foster Reservoir is a lake in Franklin County, Idaho. Its water-quality measurements are published by Idaho DEQ and shown on this page as reported.
What is the water quality of Foster Reservoir?: Foster Reservoir in Franklin County, Idaho has water-quality measurements published by Idaho DEQ, shown here as reported. Surface area: 66 acres.
Is Foster Reservoir safe to swim in?: Nutrient and algae readings are not a swimming clearance. Foster Reservoir is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.
Are there boat ramps on Foster Reservoir?: Foster Reservoir has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Foster Reservoir. Public access is listed as yes.
Can I fish at Foster Reservoir?: Foster Reservoir 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 Idaho's fish and wildlife agency, so check its current regulations before you go.