Grade D Lakes, Poor

903 lakes (17% of all graded lakes)

Grade D covers lakes with persistent water-quality issues: clarity under 7 ft, high phosphorus, frequent algal pressure. 903 lakes (17% of the dataset) land here.

Most lakes in this bracket are eutrophic — productive, often agricultural-watershed, with summer algal communities that drive much of the grade variation. Only 7% of the D-grade bracket sits in the deep category. Most D-grade lakes are shallow, which compounds the nutrient-loading problem because there is less water volume to buffer inputs.

A B C D F

903

Total Lakes

States Covered

MN 391WI 183MO 84IL 56MI 52NY 43IA 41ND 33OH 9IN 6PA 3SD 2

Lake	County	State	Clarity	Depth	Fish
Cedar Lake	Carlton	MN	2 ft	-	0
North Center Lake	Chisago	MN	3 ft	46 ft	15
Rabour Lake	Chisago	MN	3 ft	43 ft	5
Swamp Lake	Chisago	MN	1.6 ft	-	0
Mandall Lake	Chisago	MN	3 ft	26 ft	5
Helmer_nelson Pond Deep	Cook	MN	2.5 ft	-	0
Lower Pigeon Lake	Itasca	MN	4.2 ft	-	0
Dutchman Lake Deep	Cook	MN	2.3 ft	-	0
Penn Lake	Hennepin	MN	2 ft	7 ft	8
Moody Lake	Chisago	MN	4 ft	48 ft	0
Markgrafs Lake	Washington	MN	4.8 ft	-	0
Little Johanna Lake	Ramsey	MN	4.6 ft	28 ft	0
Kramer Lake	Washington	MN	1 ft	-	0
Bashaw Lake	Burnett	WI	3 ft	16 ft	3
Caesar Creek Lake	Warren	OH	3.2 ft	-	0
Caesar Creek Lake	Warren	OH	3 ft	-	0
Southern Section Lake	Washington	NY	2 ft	-	0
Sugar Creek Lake	Randolph	MO	2.5 ft	-	0
Robin Hood Lakes	Warren	MO	3 ft	-	0
Ben Branch Lake by Dam	Osage	MO	3.9 ft	-	0
Hunnewell Lake	Shelby	MO	3.2 ft	-	0
Shepard Mountain Lake Intake	Iron	MO	2.8 ft	-	0
Loto Lake	Camden	MO	2.3 ft	-	0
Long Branch Lk. Lake	Macon	MO	1.8 ft	-	0
Callaway Fork Lake	St. Charles	MO	3.3 ft	-	0
Sugar Hollow Lake	Warren	MO	3.3 ft	-	0
Pomme de Terre L. Central Arm Lake	Hickory	MO	3 ft	-	0
L. Ste. Louise Lake	St. Charles	MO	3.2 ft	-	0
Loto Lake	Camden	MO	3 ft	-	0
Lake Eleanor	Warren	MO	3 ft	-	0
Watkins Mill Lake	Clay	MO	3.2 ft	-	0
Hazel Creek Lk. East Fork Lake	Adair	MO	2.6 ft	-	0
Boathouse Lake	St. Louis city	MO	2.3 ft	-	0
L. Ste. Louise Lake	St. Charles	MO	2.6 ft	-	0
Deer Ridge Comm. Lake	Lewis	MO	2.9 ft	-	0
Indian Hills Lake Nr. Dam	Crawford	MO	3.4 ft	-	0
Stephens Lake	Boone	MO	2.6 ft	-	0
Lake Serene	Franklin	MO	2.6 ft	-	0
Peters Lake	Howard	MO	2.1 ft	-	0
O'Fallon Park Lake	St. Louis city	MO	1.6 ft	-	0
Lake Eleanor	Warren	MO	2.8 ft	-	0
Loto Morrow Hollow Mouth Lake	Camden	MO	2.3 ft	-	0
Sugar Hollow Lake	Warren	MO	3.3 ft	-	0
Prairie Lee Lake Nr. Dam	Jackson	MO	3 ft	-	0
Loto Lake	Camden	MO	3.7 ft	-	0
Indian Creek Lake	Livingston	MO	5.5 ft	-	0
Longview L. Nr. Dam Lake	Jackson	MO	3.2 ft	-	0
Cedar Lake	Randolph	MO	2.7 ft	-	0
Frisco Lake	Phelps	MO	3.8 ft	-	0
Pomme de Terre Lake	Hickory	MO	2.8 ft	-	0
Pomme de Terre Lake	Hickory	MO	2.6 ft	-	0
Lake Darling	Ward	ND	5.8 ft	28.7 ft	4
Kabetogama Lake	St. Louis	MN	4.4 ft	80 ft	16
Rainy Lake	Koochiching	MN	3.6 ft	161 ft	17
Little Shoepack Lake	St. Louis	MN	6.2 ft	25 ft	3
Kabetogama Lake	St. Louis	MN	3.8 ft	80 ft	16
Rainy Lake	St. Louis	MN	5.9 ft	161 ft	17
Kabetogama Lake	St. Louis	MN	4.8 ft	80 ft	16
Kabetogama Lake	St. Louis	MN	5.9 ft	80 ft	16
Agnes Lake	St. Louis	MN	5.2 ft	18 ft	4
Sand Point Lake	St. Louis	MN	6.6 ft	184 ft	21
Quarter Line Lake	St. Louis	MN	4.6 ft	22 ft	3
Rainy Lake	Koochiching	MN	6.6 ft	161 ft	17
Rainy Lake	Koochiching	MN	4.9 ft	161 ft	17
Rainy Lake	Koochiching	MN	3.6 ft	161 ft	17
Sand Point Lake	St. Louis	MN	5.9 ft	184 ft	21
Rainy Lake	Koochiching	MN	5.2 ft	161 ft	17
Crane Lake	St. Louis	MN	6.6 ft	80 ft	12
Namakan Lake	St. Louis	MN	4.1 ft	150 ft	18
Kabetogama Lake	St. Louis	MN	5.9 ft	80 ft	16
Round Lake	Itasca	MN	4.1 ft	24 ft	17
Horseshoe Lake	Washington	MN	4.8 ft	11.3 ft	8
Long Lake	Kandiyohi	MN	5 ft	16 ft	16
Long Lake	Pine	MN	6.5 ft	24 ft	13
Long Lake	Otter Tail	MN	3 ft	-	13
Long Lake	Watonwan	MN	2.5 ft	13 ft	13
Long Lake	Washington	MN	2.8 ft	60 ft	12
Cokato Lake	Wright	MN	6 ft	52 ft	20
Chippewa Lake	Lake	MN	6.5 ft	-	0
Twin Lake	Hennepin	MN	5.9 ft	44 ft	13
Twin Lake	Crow Wing	MN	4.5 ft	30 ft	13
Lower Lawrence Lake	Itasca	MN	4.5 ft	34 ft	0
Prairie Lake	Itasca	MN	4.4 ft	-	0
Prairie Lake	St. Louis	MN	5 ft	47 ft	15
Sullivan Lake	Wright	MN	6 ft	58 ft	11
Eagle Lake	Wright	MN	6.6 ft	38 ft	14
Ada Lake	Cook	MN	5.5 ft	13 ft	0
Zumbro Lake	Olmsted	MN	4 ft	43 ft	24
Star Lake	Cook	MN	4.9 ft	13 ft	5
Fish Lake	Scott	MN	3.9 ft	28 ft	14
Fish Lake	Pine	MN	6 ft	18 ft	0
Fish Lake	Wright	MN	3 ft	38 ft	17
Crow Wing Lake	Crow Wing	MN	6 ft	26 ft	15
Big Lake	Mahnomen	MN	2.1 ft	-	0
Bass Lake	Hennepin	MN	4 ft	31 ft	8
Bass Lake	Aitkin	MN	5 ft	58 ft	0
Bass Lake	St. Louis	MN	4.2 ft	-	0
Crooked Lake	Cook	MN	5.5 ft	66 ft	3
Cedar Lake	Hennepin	MN	4.8 ft	51 ft	15
Square Lake	Lake	MN	5.5 ft	7 ft	7

Showing 100 of 903 Grade D lakes.

Frequently Asked Questions

How many lakes have a grade of D?

There are 903 Grade D (Poor) lakes across the 12 states LakeQuality covers, led by Minnesota (391) and Wisconsin (183). This represents 17% of all graded lakes.

What does a Grade D mean?

Grade D means poor water quality with murky water (3-7 ft visibility), high phosphorus, and frequent algae. Swimming is not recommended. Fish diversity is limited.

Featured Grade D Lakes

Cedar Lake

Carlton County, MN · 2 ft clarity

North Center Lake

Chisago County, MN · 3 ft clarity

Rabour Lake

Chisago County, MN · 3 ft clarity

Swamp Lake

Chisago County, MN · 1.6 ft clarity

Mandall Lake

Chisago County, MN · 3 ft clarity

Helmer_nelson Pond Deep

Cook County, MN · 2.5 ft clarity

Source: EPA National Aquatic Resource Surveys, 2026.