Where is Second Connecticut Lake?

Second Connecticut Lake is a lake in Coos County, New Hampshire. Its water-quality measurements are published by NHDES and shown on this page as reported.

How deep is Second Connecticut Lake?

Second Connecticut Lake has a maximum depth of 60 feet and an average depth of 20 feet. The lake covers 1102 acres.

Are there boat ramps on Second Connecticut Lake?

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

Can I fish at Second Connecticut Lake?

Second Connecticut 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 New Hampshire's fish and wildlife agency, so check its current regulations before you go.

Second Connecticut Lake

Coos County, New Hampshire1,102 acresView map Directions

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

Max depth

60 ft

Bathymetric survey

Area

1,102 acres

Surface area

Shoreline

10.7 mi

Measured length

Impaired · Mercury
60 ft max depth
Public access

See the measurements Directions Where to stay

Second Connecticut Lake in Coos County, New Hampshire has water-quality measurements published by NHDES, shown here as reported. Maximum depth: 60 ft. Surface area: 1102 acres.

Loading map…

Second Connecticut Lake is a 1,102-acre lake in Coos County, New Hampshire with a maximum depth of 60 feet (20-foot average). Limited fish-species data available. 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 Second Connecticut Lake is good for

From access and monitoring records, not editorial picks.

Boat launch1 documented ramp
Deep water60 ft surveyed max depth
Big water1,102 acres

Swimming conditions

No reading

Not rated

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

Whether Second Connecticut Lake is safe to swim in today is a call for the New Hampshire Department of Environmental Services and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.

Get alerts for Second Connecticut Lake →

Water quality measurements for Second Connecticut Lake

These are the measurements NHDES publishes for Second Connecticut 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 Second Connecticut Lake

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

Lake Details

Max depth

60 ft

Average depth

20 ft

Surface area

1,102 acres

Shoreline

10.7 mi

Public access

Yes

Listed by NHDES

The depth above comes from a bathymetric survey of this lake, not from a regional estimate.

Recreation & Access

Boat Landings

Yes

Public Access

Second Connecticut LakePublic

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

Stays via Stay22

Stays near Second Connecticut Lake

Compare lakeside cabins, hotels, and vacation rentals near Second Connecticut Lake in Coos County, New Hampshire — 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 Second Connecticut 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.

Follow Second Connecticut Lake’s readings

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

Or email

Fishing Second Connecticut Lake

→ Second Connecticut Lake fishing regulations (limits, seasons, special rules)

EPA Impairment Status

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

Causes of impairment

MercurypH / acidity

Designated uses not supporting: Aquatic life, Fish consumption.

A Total Maximum Daily Load (TMDL) plan has been approved.

Source: EPA ATTAINS assessment unit NHLAK801010101-01 · Official waterbody report

Nearby Lakes in Coos County

East Inlet Flowage2.3 miView →Big Brook Bog2.9 miView →Scott Bog4.3 miView →Third Connecticut Lake6.1 miView →Round Pond5.1 miView →First Connecticut Lake-Deep Spot6.1 miView →

Frequently asked questions about Second Connecticut Lake

Where is Second Connecticut Lake?: Second Connecticut Lake is a lake in Coos County, New Hampshire. Its water-quality measurements are published by NHDES and shown on this page as reported.
What is the water quality of Second Connecticut Lake?: Second Connecticut Lake in Coos County, New Hampshire has water-quality measurements published by NHDES, shown here as reported. Maximum depth: 60 ft. Surface area: 1102 acres.
Is Second Connecticut Lake safe to swim in?: Nutrient and algae readings are not a swimming clearance. Second Connecticut Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, pH / acidity. Check local advisories before you swim.
How deep is Second Connecticut Lake?: Second Connecticut Lake has a maximum depth of 60 feet and an average depth of 20 feet. The lake covers 1102 acres.
Are there boat ramps on Second Connecticut Lake?: Second Connecticut Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Second Connecticut Lake. Public access is listed as yes.
Can I fish at Second Connecticut Lake?: Second Connecticut 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 New Hampshire's fish and wildlife agency, so check its current regulations before you go.