Where is Sweetwater Reservoir?

Sweetwater Reservoir is a lake in San Diego County, California. Its water-quality measurements are published by SWRCB and shown on this page as reported.

Sweetwater Reservoir

San Diego County, California689 acresView map Directions

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

Area

689 acres

Surface area

Impaired · Mercury
Limited data

See the measurements Directions Where to stay

Sweetwater Reservoir in San Diego County, California has water-quality measurements published by SWRCB, shown here as reported. Surface area: 689 acres.

Loading map…

Sweetwater Reservoir is a 689-acre lake in San Diego County, California.

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

Swimming conditions

No reading

Limited data

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

Whether Sweetwater Reservoir 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.

Get alerts for Sweetwater Reservoir →

Water quality measurements for Sweetwater Reservoir

These are the measurements SWRCB publishes for Sweetwater 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.

Ask about Sweetwater Reservoir

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

Lake Details

Surface area

689 acres

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

Stays via Stay22

Stays near Sweetwater Reservoir

Compare lakeside cabins, hotels, and vacation rentals near Sweetwater Reservoir in San Diego 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 Sweetwater Reservoir

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.

Follow Sweetwater Reservoir’s readings

Email me when new measurements post for this lake. Updates stay free.

Or email

Fishing Sweetwater Reservoir

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

EPA Impairment Status

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

Causes of impairment

MercuryOxygen depletion (low DO)

Designated uses not supporting: Drinking water, Fish consumption.

Source: EPA ATTAINS assessment unit CAL9092100019991117112141 · Official waterbody report

Nearby Lakes in San Diego County

Upper Otay Lake4.3 miView →Lower Otay Lake6.3 miView →Murray Reservoir7.1 miView →Lake Jennings12.5 miView →Loveland Reservoir14.3 miView →Lake Miramar16.4 miView →

Frequently asked questions about Sweetwater Reservoir

Where is Sweetwater Reservoir?: Sweetwater Reservoir is a lake in San Diego County, California. Its water-quality measurements are published by SWRCB and shown on this page as reported.
What is the water quality of Sweetwater Reservoir?: Sweetwater Reservoir in San Diego County, California has water-quality measurements published by SWRCB, shown here as reported. Surface area: 689 acres.
Is Sweetwater Reservoir safe to swim in?: Nutrient and algae readings are not a swimming clearance. Sweetwater Reservoir is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, oxygen depletion (low DO). Check local advisories before you swim.