Late afternoon sun over Slim Lake, scattering a bright path across wind-textured water

Grafton County Lake Quality

New Hampshire, 70 lakes, measured by NHDES

Grafton County in New Hampshire carries 70 monitored lakes — one of the lake-richer counties in our dataset. Coverage that dense usually reflects active lake-association sampling alongside state-agency monitoring. 23 of those lakes carry recent nutrient and algae readings. The county-level summary describes that subset, not every water body listed. Most monitored lakes in Grafton County carry favourable nutrient and algae readings for New Hampshire.

Most of the county's monitored lakes are shallow, under 50 feet, which means wind keeps the water column mixed all summer and sediment-bound phosphorus releases back into the surface layer whenever the bottom is disturbed. Armington Lake-Deep Spot has the lowest nutrient and algae readings in the county.

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Planning a trip? Check special fishing regulations for Armington Lake-Deep Spot — or check the official New Hampshire fishing regulations.

All Lakes in Grafton County

70 lakes · 23 ranked on readings, 47 without enough sampling23 lakes ranked on readings · 47 without enough sampling, hidden

Include not-rated lakes (47)

#	Lake	Clarity	Phosphorus	Algae	Trophic	Max Depth	Access
1	Armington Lake-Deep SpotGrafton	No recent samples	6.3 µg/L	1.1 µg/L	No recent samples	No recent samples	✓ Public
2	Canaan Street Lake-Deep SpotGrafton	No recent samples	6.4 µg/L	2 µg/L	No recent samples	No recent samples	✓ Public
3	Goose Pond-Deep SpotGrafton	No recent samples	10.8 µg/L	3 µg/L	No recent samples	No recent samples	✓ Public
4	Kilton Pond-Deep SpotGrafton	No recent samples	11.3 µg/L	4.2 µg/L	No recent samples	No recent samples	✓ Public
5	Lake Tarleton-Deep SpotGrafton	No recent samples	6.3 µg/L	1.9 µg/L	No recent samples	No recent samples	✓ Public
6	Spectacle Pond-Deep SpotGrafton	No recent samples	13.9 µg/L	4.1 µg/L	No recent samples	No recent samples	✓ Public
7	Stinson Lake-Deep SpotGrafton	No recent samples	5.2 µg/L	1.6 µg/L	No recent samples	No recent samples	Not recorded
8	Dodge Pond-Deep SpotGrafton	No recent samples	14.1 µg/L	8.5 µg/L	No recent samples	No recent samples	Not recorded
9	Dodge Pond-InletGrafton	No recent samples	12.1 µg/L	No recent samples	No recent samples	No recent samples	Not recorded
10	Lake Katherine-Deep SpotGrafton	No recent samples	7.6 µg/L	10.7 µg/L	No recent samples	No recent samples	Not recorded
11	Loon Lake-Deep SpotGrafton	No recent samples	10.8 µg/L	4.8 µg/L	No recent samples	No recent samples	✓ Public
12	Newfound Lake-Deep SpotGrafton	No recent samples	5.1 µg/L	No recent samples	No recent samples	No recent samples	✓ Public
13	Post Pond-Deep SpotGrafton	No recent samples	13.1 µg/L	6.8 µg/L	No recent samples	No recent samples	Not recorded
14	Reservoir Pond-Deep SpotGrafton	No recent samples	10.4 µg/L	5 µg/L	No recent samples	No recent samples	✓ Public
15	South Mountain Lake-CoveGrafton	No recent samples	9.7 µg/L	No recent samples	No recent samples	No recent samples	Not recorded
16	South Mountain Lake-Deep SpotGrafton	No recent samples	12 µg/L	5.1 µg/L	No recent samples	No recent samples	Not recorded
17	South Mountain Lake-OutletGrafton	No recent samples	9.7 µg/L	No recent samples	No recent samples	No recent samples	Not recorded
18	Spectacle Pond-VlapGrafton	No recent samples	7.8 µg/L	2.7 µg/L	No recent samples	No recent samples	✓ Public
19	White Oak PondGrafton	No recent samples	14.5 µg/L	No recent samples	No recent samples	No recent samples	Not recorded
20	Gardner Lake-Deep SpotGrafton	No recent samples	16.2 µg/L	5.8 µg/L	No recent samples	No recent samples	Not recorded
21	Mooney-Clark Public Landing LakeGrafton	No recent samples	16.2 µg/L	No recent samples	No recent samples	No recent samples	✓ Public
22	Partridge Lake-Deep SpotGrafton	No recent samples	16.9 µg/L	6.4 µg/L	No recent samples	No recent samples	✓ Public
23	Round Pond-Deep SpotGrafton	No recent samples	18.9 µg/L	8.3 µg/L	No recent samples	No recent samples	Not recorded
	Baker Floodwater Reservoir SiteGrafton	No recent samples	No recent samples	No recent samples	No recent samples	29 ft	Not recorded
	Bath Covered Bridge LakeGrafton	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	Beaver Pond-Deep SpotGrafton	No recent samples	14.2 µg/L	No recent samples	No recent samples	No recent samples	Not recorded
	Boston Lot LakeGrafton	No recent samples	No recent samples	No recent samples	No recent samples	22 ft	Not recorded
	Branch PondGrafton	No recent samples	14.3 µg/L	No recent samples	No recent samples	No recent samples	Not recorded
	Campton PondGrafton	No recent samples	No recent samples	No recent samples	No recent samples	5 ft	Not recorded
	Church PondsGrafton	No recent samples	No recent samples	No recent samples	No recent samples	20 ft	Not recorded
	Clark PondGrafton	No recent samples	No recent samples	No recent samples	No recent samples	45 ft	✓ Public
	Connecticut River ReservoirGrafton	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	Crystal LakeGrafton	No recent samples	No recent samples	No recent samples	No recent samples	50 ft	✓ Public
	Cummins PondGrafton	No recent samples	No recent samples	No recent samples	No recent samples	40 ft	Not recorded
	Dodge Pond-BeachGrafton	No recent samples	33.3 µg/L	No recent samples	No recent samples	No recent samples	Not recorded
	Echo Lake-Deep SpotGrafton	No recent samples	5 µg/L	2.9 µg/L	No recent samples	No recent samples	✓ Public
	Elbow PondGrafton	No recent samples	No recent samples	No recent samples	No recent samples	30 ft	Not recorded
	Ellsworth PondGrafton	No recent samples	No recent samples	No recent samples	No recent samples	25 ft	Not recorded
	Flat Mountain PondsGrafton	No recent samples	No recent samples	No recent samples	No recent samples	10 ft	Not recorded
	Fletcher ReservoirGrafton	No recent samples	No recent samples	No recent samples	No recent samples	20 ft	Not recorded
	French Pond-Deep SpotGrafton	No recent samples	23.7 µg/L	No recent samples	No recent samples	No recent samples	✓ Public
	George PondGrafton	No recent samples	No recent samples	No recent samples	No recent samples	10 ft	✓ Public
	Grafton PondGrafton	No recent samples	No recent samples	No recent samples	No recent samples	70 ft	✓ Public
	Harveys LakeGrafton	No recent samples	89.5 µg/L	No recent samples	No recent samples	No recent samples	Not recorded
	Indian PondGrafton	No recent samples	No recent samples	No recent samples	No recent samples	10 ft	✓ Public
	Lary PondGrafton	No recent samples	No recent samples	No recent samples	No recent samples	9.8 ft	Not recorded
	Line PondGrafton	No recent samples	No recent samples	No recent samples	No recent samples	34.1 ft	Not recorded
	Little Squam LakeGrafton	No recent samples	No recent samples	No recent samples	No recent samples	70 ft	Not recorded
	Long PondGrafton	No recent samples	No recent samples	No recent samples	No recent samples	5 ft	✓ Public
	Lower Baker PondGrafton	No recent samples	No recent samples	No recent samples	No recent samples	30 ft	✓ Public
	Mirror LakeGrafton	No recent samples	No recent samples	No recent samples	No recent samples	30 ft	Not recorded
	Moore ReservoirGrafton	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	✓ Public
	North Mountain Lake-BeachGrafton	No recent samples	9.2 µg/L	No recent samples	No recent samples	No recent samples	Not recorded
	Ogontz LakeGrafton	No recent samples	No recent samples	No recent samples	No recent samples	70 ft	Not recorded
	Oliverian PondGrafton	No recent samples	No recent samples	No recent samples	No recent samples	10 ft	Not recorded
	Parker ReservoirGrafton	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	Pearl LakeGrafton	No recent samples	No recent samples	No recent samples	No recent samples	20 ft	Not recorded
	Perch PondGrafton	No recent samples	No recent samples	No recent samples	No recent samples	45 ft	Not recorded
	Post Pond-Town BeachGrafton	No recent samples	10.3 µg/L	No recent samples	No recent samples	No recent samples	✓ Public
	Pout PondGrafton	No recent samples	No recent samples	No recent samples	No recent samples	8.2 ft	Not recorded
	Russell PondGrafton	No recent samples	No recent samples	No recent samples	No recent samples	60 ft	Not recorded
	Sawyer Pond-Deep SpotGrafton	No recent samples	5 µg/L	No recent samples	No recent samples	No recent samples	Not recorded
	Smith PondGrafton	No recent samples	No recent samples	No recent samples	No recent samples	30 ft	Not recorded
	South Mountain Lake-BeachGrafton	No recent samples	9.7 µg/L	No recent samples	No recent samples	No recent samples	Not recorded
	Stevenson PondGrafton	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	Stinson Lake-Near OutletGrafton	No recent samples	5.2 µg/L	No recent samples	No recent samples	No recent samples	✓ Public
	Streeter PondGrafton	No recent samples	No recent samples	No recent samples	No recent samples	15 ft	✓ Public
	Tewksbury PondGrafton	No recent samples	No recent samples	No recent samples	No recent samples	45 ft	✓ Public
	Upper Baker PondGrafton	No recent samples	No recent samples	No recent samples	No recent samples	15 ft	✓ Public
	Wachipauka PondGrafton	No recent samples	No recent samples	No recent samples	No recent samples	30 ft	Not recorded

NR = no nutrient or algae reading on record. The measurements are published as the authority reports them. Where the data comes from.

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Source: the New Hampshire Department of Environmental Services. See data sources.