Where is Lake Monomonac-Loon Bay?

Lake Monomonac-Loon Bay is a lake in Cheshire County, New Hampshire. Its water-quality measurements are published by NHDES and shown on this page as reported.

Lake Monomonac-Loon Bay

Cheshire County, New HampshireView map Directions

NHDES publishes the water-quality measurements for Lake Monomonac-Loon Bay. Here is what has been measured.

Phosphorus

11.2 µg/L

Typical for New Hampshire

Measured by NHDES

Type

Oligotrophic

Trophic class

Oligotrophic
Impaired · Algal growth
Limited data

See the measurements Directions Where to stay

Lake Monomonac-Loon Bay in Cheshire County, New Hampshire has water-quality measurements published by NHDES, shown here as reported. Phosphorus: 11.2 µg/L.

Loading map…

Lake Monomonac-Loon Bay is a cold, clear oligotrophic lake in Cheshire County, New Hampshire. Compared to the 37 other monitored lakes in Cheshire County, Lake Monomonac-Loon Bay ranks #12 for water quality.

Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2022-07-05. Methodology: how these readings are compared.

Swimming conditions

Readings only

Bacteria advisory

Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.

Nutrient and algae readings are not a swimming clearance. Lake Monomonac-Loon Bay is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, biotoxins, mercury, nuisance exotic species, nutrients (phosphorus, nitrogen), pH / acidity. Check local advisories before you swim.

Whether Lake Monomonac-Loon Bay 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.

Compare swimming lakes near Albany →

Get alerts for Lake Monomonac-Loon Bay →

Water quality measurements for Lake Monomonac-Loon Bay

These are the measurements NHDES publishes for Lake Monomonac-Loon Bay, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.

No clarity data. Phosphorus 11.2 µg/L. TSI 39.

Water quality readings
Measure	Reading	Where it sits
Water clarity (Secchi depth)		No reading How deep a black-and-white disk stays visible from the surface. Higher is clearer.
Total phosphorus	11.2µg/L	Good GoodFairPoor
Chlorophyll-a (algae)		No reading The green pigment in algae — a direct measure of how much algae is in the water.
Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a.	39	Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic

Low nutrients, clear water. No reading is a swimming clearance.

Ask about Lake Monomonac-Loon Bay

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

Stays via Stay22

Stays near Lake Monomonac-Loon Bay

Compare lakeside cabins, hotels, and vacation rentals near Lake Monomonac-Loon Bay in Cheshire 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 Lake Monomonac-Loon Bay

Prices for Oct 9–11, 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 Lake Monomonac-Loon Bay’s readings

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

Or email

Fishing Lake Monomonac-Loon Bay

→ Lake Monomonac-Loon Bay fishing regulations (limits, seasons, special rules)

EPA Impairment Status

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

Causes of impairment

Algal growthBiotoxinsMercuryNuisance exotic speciesNutrients (phosphorus, nitrogen)pH / acidity

Designated uses not supporting: Aquatic life, Fish consumption, Recreation.

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

Source: EPA ATTAINS assessment unit NHLAK802020103-06 · Official waterbody report

Nearby Lakes in Cheshire County

Lake Monomonac-Coot BayEutrophic0.8 miView →Pecker Pond-Deep Spot1.1 miView →Crowcroft Pond—View →Emerson Pond-Wozniak Beach2.6 miView →Emerson Pond-Cathedral Beach2.9 miView →Emerson Pond-Deep SpotMesotrophic3 miView →

Frequently asked questions about Lake Monomonac-Loon Bay

Where is Lake Monomonac-Loon Bay?: Lake Monomonac-Loon Bay is a lake in Cheshire County, New Hampshire. Its water-quality measurements are published by NHDES and shown on this page as reported.
What is the water quality of Lake Monomonac-Loon Bay?: Lake Monomonac-Loon Bay in Cheshire County, New Hampshire has water-quality measurements published by NHDES, shown here as reported. Phosphorus: 11.2 µg/L.
Is Lake Monomonac-Loon Bay safe to swim in?: Nutrient and algae readings are not a swimming clearance. Lake Monomonac-Loon Bay is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, biotoxins, mercury, nuisance exotic species, nutrients (phosphorus, nitrogen), pH / acidity. Check local advisories before you swim.

Explore Lake Monomonac-Loon Bay across LakeQuality

Lake Fishing Forecast

Species activity outlook by water temperature and season

More lakes in New Hampshire

All New Hampshire lakes

Every New Hampshire lake with its NHDES measurements

Lake water quality by country

Official ratings and named-lake measurements