Blue-Green Algae Bloom Tracker

Lakes with a current bloom

111 lakes had an elevated blue-green algae reading from EPA CyAN satellite data in the last four weeks. Satellite readings cover open water and can lag a bloom by days — keep people and dogs out of any water with visible scum, and check your state’s current advisory.

Lake	State	Bloom risk	Cyanobacteria	Reading
Rice Lake Anoka County	Minnesota	Very High	2,910,717 cells/mL	Jul 19
Typo Lake Anoka County	Minnesota	Very High	2,606,154 cells/mL	Jul 19
Goose Lake Carver County	Minnesota	Very High	2,147,831 cells/mL	Jul 18
Eagle Lake Racine County	Wisconsin	Very High	2,089,296 cells/mL	Jul 18
Mud Lake Barron County	Wisconsin	Very High	2,089,296 cells/mL	Jul 18
Charlotte Lake Stevens County	Minnesota	Very High	2,032,357 cells/mL	Jul 19
Union Lake Rice County	Minnesota	Very High	1,976,970 cells/mL	Jul 18
Elk Lake Sherburne County	Minnesota	Very High	1,976,970 cells/mL	Jul 19
Clear Lake Le Sueur County	Minnesota	Very High	1,870,682 cells/mL	Jul 19
Hall Lake Martin County	Minnesota	Very High	1,819,701 cells/mL	Jul 19
Long Lake Stearns County	Minnesota	Very High	1,770,109 cells/mL	Jul 18
Cedar Lake Scott County	Minnesota	Very High	1,674,943 cells/mL	Jul 19
Fountain Lake Wright County	Minnesota	Very High	1,674,943 cells/mL	Jul 19
Tainter Lake Dunn County	Wisconsin	Very High	1,629,296 cells/mL	Jul 18
Eagle Lake Blue Earth County	Minnesota	Very High	1,584,893 cells/mL	Jul 19
Crystal Lake Blue Earth County	Minnesota	Very High	1,584,893 cells/mL	Jul 19
Petenwell Flowage Lake Juneau County	Wisconsin	Very High	1,584,893 cells/mL	Jul 18
Peltier Lake Anoka County	Minnesota	Very High	1,499,685 cells/mL	Jul 19
Clear Lake Meeker County	Minnesota	Very High	1,499,685 cells/mL	Jul 19
Clear Lake Martin County	Minnesota	Very High	1,419,058 cells/mL	Jul 18
Clear Lake Brown County	Minnesota	Very High	1,342,765 cells/mL	Jul 18
Cedar Lake Rice County	Minnesota	Very High	1,342,765 cells/mL	Jul 19
East Solomon Lake Kandiyohi County	Minnesota	Very High	1,235,948 cells/mL	Jul 18
Maple Lake Todd County	Minnesota	Very High	1,202,264 cells/mL	Jul 19
Lake Puckaway Green Lake County	Wisconsin	Very High	1,202,264 cells/mL	Jul 18
Marion Lake McLeod County	Minnesota	Very High	1,169,499 cells/mL	Jul 18
Lake Koshkonong Jefferson County	Wisconsin	Very High	1,137,627 cells/mL	Jul 18
East Auburn Lake Carver County	Minnesota	Very High	1,106,624 cells/mL	Jul 18
Curtis Lake Yellow Medicine County	Minnesota	Very High	1,047,129 cells/mL	Jul 18
Fish Lake Jackson County	Minnesota	Very High	1,018,591 cells/mL	Jul 18
Elk Lake Sherburne County	Minnesota	Very High	1,018,591 cells/mL	Jul 19
Clear Lake Jackson County	Minnesota	High	990,832 cells/mL	Jul 18
Rice Lake Morrison County	Minnesota	High	937,562 cells/mL	Jul 18
Lake Butte des Morts Winnebago County	Wisconsin	High	912,011 cells/mL	Jul 18
Tetonka Lake Le Sueur County	Minnesota	High	862,979 cells/mL	Jul 18
Stowe Lake Douglas County	Minnesota	High	839,460 cells/mL	Jul 19
Prairie Lake Barron County	Wisconsin	High	839,460 cells/mL	Jul 18
Lake Columbia County	Wisconsin	High	839,460 cells/mL	Jul 18
Ann Lake Kanabec County	Minnesota	High	816,582 cells/mL	Jul 9
Big Swan Lake Meeker County	Minnesota	High	794,328 cells/mL	Jul 18
Eagle Lake Sherburne County	Minnesota	High	794,328 cells/mL	Jul 18
Lake Winneconne Winnebago County	Wisconsin	High	772,681 cells/mL	Jul 18
Roberds Lake Rice County	Minnesota	High	731,139 cells/mL	Jul 19
Swan Lake McLeod County	Minnesota	High	731,139 cells/mL	Jul 18
Hook Lake McLeod County	Minnesota	High	691,831 cells/mL	Jul 18
Lake Wisconsin Whalen'S Grade Columbia County	Wisconsin	High	672,977 cells/mL	Jul 18
Long Lake Hennepin County	Minnesota	High	654,636 cells/mL	Jul 18
Pokegama Lake Pine County	Minnesota	High	654,636 cells/mL	Jul 19
Star Lake Meeker County	Minnesota	High	636,796 cells/mL	Jul 18
Rice Lake Hennepin County	Minnesota	High	619,441 cells/mL	Jul 6
Maple Lake Polk County	Minnesota	High	570,164 cells/mL	Jul 19
Long Lake Price County	Wisconsin	High	570,164 cells/mL	Jul 18
Lake Waubesa Dane County	Wisconsin	High	554,626 cells/mL	Jul 18
Lake Poygan Winnebago County	Wisconsin	High	539,511 cells/mL	Jul 18
Schram Lake Beltrami County	Minnesota	High	524,807 cells/mL	Jul 19
Ann Lake Wright County	Minnesota	High	524,807 cells/mL	Jul 18
Rice Lake Barron County	Wisconsin	High	524,807 cells/mL	Jul 18
White Lake Waupaca County	Wisconsin	High	524,807 cells/mL	Jul 6
Horseshoe Lake Itasca County	Minnesota	High	510,505 cells/mL	Jul 19
Altoona Lake Eau Claire County	Wisconsin	High	496,592 cells/mL	Jul 18
Goose Lake Pope County	Minnesota	High	469,894 cells/mL	Jul 18
Oak Lake Polk County	Minnesota	High	469,894 cells/mL	Jul 19
Knife Lake Kanabec County	Minnesota	High	469,894 cells/mL	Jul 19
Nelson Lake Sawyer County	Wisconsin	High	432,514 cells/mL	Jul 18
Emily Lake Le Sueur County	Minnesota	High	409,261 cells/mL	Jul 18
Rice Lake Stearns County	Minnesota	High	398,107 cells/mL	Jul 6
Green Lake Isanti County	Minnesota	High	387,258 cells/mL	Jul 9
Round Lake Jackson County	Minnesota	High	376,704 cells/mL	Jul 19
Ann Lake Pope County	Minnesota	High	376,704 cells/mL	Jul 9
Europe Lake Door County	Wisconsin	High	376,704 cells/mL	Jul 18
Pelican Lake Pope County	Minnesota	High	337,287 cells/mL	Jul 18
Upper Red Lake: West-Central Beltrami County	Minnesota	High	337,287 cells/mL	Jul 19
Halsey Lake Florence County	Wisconsin	High	328,095 cells/mL	Jul 18
Clear Lake Waseca County	Minnesota	High	319,154 cells/mL	Jul 19
Turtle Lake Polk County	Minnesota	High	310,456 cells/mL	Jul 19
Ballantyne Lake Blue Earth County	Minnesota	High	293,765 cells/mL	Jul 18
Lac Sault Dore Lake Price County	Wisconsin	High	255,859 cells/mL	Jul 18
Volney Lake Le Sueur County	Minnesota	High	222,844 cells/mL	Jul 18
Fish Lake Kanabec County	Minnesota	High	216,770 cells/mL	Jul 11
Medicine Lake Hennepin County	Minnesota	High	205,116 cells/mL	Jul 18
Lake Kegonsa Dane County	Wisconsin	High	205,116 cells/mL	Jul 18
Cedar Lake Polk County	Wisconsin	High	188,799 cells/mL	Jul 9
Butternut Lake Price County	Wisconsin	High	188,799 cells/mL	Jul 18
Deer Lake Otter Tail County	Minnesota	High	173,780 cells/mL	Jul 6
Chippewa Flowage Lake Sawyer County	Wisconsin	High	173,780 cells/mL	Jul 11
Kabetogama Lake St. Louis County	Minnesota	High	159,956 cells/mL	Jul 4
Linwood Lake Anoka County	Minnesota	High	159,956 cells/mL	Jul 18
Round Lake Itasca County	Minnesota	High	151,356 cells/mL	Jul 18
Johanna Lake Pope County	Minnesota	High	147,231 cells/mL	Jul 18
Boot Lake Vilas County	Wisconsin	High	147,231 cells/mL	Jul 9
North Long Lake Crow Wing County	Minnesota	High	139,316 cells/mL	Jul 18
Sewell Lake Otter Tail County	Minnesota	High	139,316 cells/mL	Jul 4
Emily Lake Pope County	Minnesota	High	131,826 cells/mL	Jul 9
Long Lake Otter Tail County	Minnesota	High	118,032 cells/mL	Jul 18
Dairyland Reservoir Rusk County	Wisconsin	High	108,643 cells/mL	Jul 18
Long Lake Kandiyohi County	Minnesota	High	102,802 cells/mL	Jul 9
Irving Lake Beltrami County	Minnesota	High	102,802 cells/mL	Jul 18
Minong Flowage Lake Washburn County	Wisconsin	High	102,802 cells/mL	Jul 9
Red Cedar Lake Barron County	Wisconsin	Moderate	71,779 cells/mL	Jul 7
Solberg Lake Price County	Wisconsin	Moderate	66,069 cells/mL	Jul 9
Lake St. Croix St. Croix County	Wisconsin	Moderate	55,976 cells/mL	Jul 18
Round Lake Otter Tail County	Minnesota	Moderate	50,119 cells/mL	Jul 18
Franklin Lake Forest County	Wisconsin	Moderate	48,753 cells/mL	Jul 6
Round Lake Aitkin County	Minnesota	Moderate	42,462 cells/mL	Jul 13
Sallie Lake Becker County	Minnesota	Moderate	42,462 cells/mL	Jul 4
Oak Lake Pine County	Minnesota	Moderate	42,462 cells/mL	Jul 7
Pike Lake Price County	Wisconsin	Moderate	42,462 cells/mL	Jul 9
Allie Lake Renville County	Minnesota	Moderate	41,305 cells/mL	Jul 18
Whitefish Lake Sawyer County	Wisconsin	Moderate	38,019 cells/mL	Jul 7
Portage Lake Hubbard County	Minnesota	Moderate	36,983 cells/mL	Jul 4
Eagle Lake Kandiyohi County	Minnesota	Moderate	29,648 cells/mL	Jul 9

Bringing a dog? See our blue-green algae & dogs guide.

Bloom-prone lakes by state

Lakes most likely to develop blue-green algae (cyanobacteria) blooms across our 36 covered states, based on chlorophyll-a measurements above 20 µg/L. These are bloom-prone waters — not necessarily active advisories.

For real-time current advisories, always check the state agencies directly:

Bloom-prone lakes in Minnesota

Lake	Algae	Grade
Ardmore Lake Hennepin County	185 µg/L	F
Augusta Lake Dakota County	130 µg/L	F
Lamplighter Park Lake Hennepin County	112.5 µg/L	F
Cody Lake Rice County	97 µg/L	F
Rebecca Lake Dakota County	95 µg/L	F
Mud Lake Washington County	89 µg/L	F
Farquar Lake Dakota County	88 µg/L	F
Phelps Lake Rice County	85 µg/L	F
Hall Lake Martin County	84.1 µg/L	F
Long Lake Dakota County	82 µg/L	F
Sisseton Lake Martin County	80.1 µg/L	F
Rose Lake Washington County	77 µg/L	F
George Lake Martin County	74.8 µg/L	F
Downs Lake Washington County	70.5 µg/L	F
Dickman Lake Dakota County	70 µg/L	F
Nielson Lake Washington County	69 µg/L	F
Lilly Lake Dakota County	69 µg/L	F
Goose Lake Washington County	66 µg/L	F
Amber Lake Martin County	65.4 µg/L	F
Budd Lake Martin County	64.1 µg/L	F
Goose Lake Goodhue County	60.5 µg/L	F
Cedar Lake Scott County	58 µg/L	F
Alimagnet Lake Dakota County	58 µg/L	D
Victoria Lake Hennepin County	56 µg/L	F
Snelling Lake Hennepin County	53.5 µg/L	F

All algae-risk lakes in Minnesota →

Bloom-prone lakes in Wisconsin

Lake	Algae	Grade
Milwaukee Harbor South Half Lake Milwaukee County	31 µg/L	D
Milwaukee Harbor North Half Lake Milwaukee County	26 µg/L	C
Milwaukee Harbor Lake Milwaukee County	26 µg/L	C
Milwaukee Harbor Lake Milwaukee County	23 µg/L	D
Big Round Lake Polk County	21 µg/L	C

All algae-risk lakes in Wisconsin →

Bloom-prone lakes in Illinois

Lake	Algae	Grade
Quiver Lake Mason County	140 µg/L	F
Boujan Swale Lake Cass County	136 µg/L	F
Long Lake Lake County	47.6 µg/L	D

All algae-risk lakes in Illinois →

Bloom-prone lakes in Michigan

Lake	Algae	Grade
Community College Pond Chippewa County	97.4 µg/L	D
North Pond Chippewa County	52.7 µg/L	C
South Pond Chippewa County	37.5 µg/L	D
Lake Diane South Basin; Amboy Township Hillsdale County	29 µg/L	D
Fox Lake Central Basin; Dalton Township Muskegon County	29 µg/L	D
Palmer Lake Central Basin; Colon Township St. Joseph County	21 µg/L	D

All algae-risk lakes in Michigan →

Bloom-prone lakes in Iowa

Lake	Algae	Grade
Cedar Lake Linn County	129 µg/L	F
Hannen Lake Benton County	119.9 µg/L	F
Meyers Lake Black Hawk County	116.5 µg/L	F
Lake Orient Adair County	110 µg/L	F
Rock Creek Max Depth Lake Jasper County	107.5 µg/L	F
Littlefield Lake Audubon County	103.1 µg/L	F
Alice Wyth Lake Black Hawk County	101.6 µg/L	F
Lake Hendricks Howard County	99.1 µg/L	F
Casey Lake Tama County	95.5 µg/L	F
Desoto Bend Lake Harrison County	93.4 µg/L	F
Avenue of the Saints Lake Bremer County	89.7 µg/L	F
Indian Lake Van Buren County	89.1 µg/L	F
Union Grove Lake Tama County	88.5 µg/L	F
Ottumwa Lagoon Max Depth Lake Wapello County	86.9 µg/L	F
East Lake Osceola Clarke County	81.6 µg/L	F
Badger Creek Max Depth Lake Madison County	77.7 µg/L	F
Lake Manawa Pottawattamie County	77 µg/L	F
Little Wall Lake Hamilton County	76.6 µg/L	F
Swan Lake Max Depth Carroll County	74 µg/L	F
Williamson Pond Max Depth Lucas County	73.9 µg/L	F
Prairie Rose Lake Shelby County	73.6 µg/L	F
Lower Pine Lake Hardin County	73.5 µg/L	F
Sands Timber Lake Taylor County	70.1 µg/L	F
Little River Lake Decatur County	70 µg/L	F
Mckinley Lake Union County	69.3 µg/L	F

All algae-risk lakes in Iowa →

Bloom-prone lakes in Ohio

Lake	Algae	Grade
Buck Creek Lake Clark County	39.7 µg/L	D
Buck Creek Lake Clark County	39.5 µg/L	D
Buck Creek Lake Clark County	36.8 µg/L	D
Buck Creek Lake Clark County	35.7 µg/L	D
Caesar Creek Lake Warren County	23.5 µg/L	C
Caesar Creek Lake Warren County	22.7 µg/L	D
Caesar Creek Lake Warren County	20.1 µg/L	D

All algae-risk lakes in Ohio →

Bloom-prone lakes in Pennsylvania

No lakes with chlorophyll-a above 20 µg/L in our current dataset.

All algae-risk lakes in Pennsylvania →

Bloom-prone lakes in New York

Lake	Algae	Grade
Irondequoit Bay Lake Monroe County	24.2 µg/L	D

All algae-risk lakes in New York →

Bloom-prone lakes in Missouri

Lake	Algae	Grade
Lake Wooldridge Saline County	777.8 µg/L	F
Pomme de Terre Lake Hickory County	360.5 µg/L	F
Bee Tree Lake St. Louis County	296.4 µg/L	F
Pomme de Terre Lake Hickory County	254 µg/L	F
Knox Village Lake Jackson County	193.5 µg/L	F
Mckay Park Lake Cole County	187.1 µg/L	F
Crowder S.P. Lake Grundy County	176.4 µg/L	F
Limpp Lake Gentry County	166.5 µg/L	F
Loose Park Lake Jackson County	159.8 µg/L	F
Drexel City Reservoir South Nr. Dam Bates County	152.7 µg/L	F
Lewis Lake Stoddard County	149.8 µg/L	F
Harrison County Lake Harrison County	134.4 µg/L	F
Pomme de Terre L. Lake Hickory County	132.3 µg/L	D
Izaak Walton Lake Vernon County	123.1 µg/L	F
Edwin A Pape Lake Lafayette County	116.6 µg/L	F
Shelbyville Lake Shelby County	112.4 µg/L	F
Jamesport Community Lake Daviess County	111.4 µg/L	F
Teal Lake Audrain County	97.7 µg/L	F
Troost Lake Jackson County	95.8 µg/L	F
Creve Coeur Lake Nr. Boat Ramp St. Louis County	92.9 µg/L	F
Lake Luna Cass County	92.7 µg/L	F
Mark Twain Lake Monroe County	92.6 µg/L	F
Hemitite Lake St. Francois County	91.9 µg/L	F
Valley Lake Jackson County	87.2 µg/L	D
Chaumiere Lake Clay County	86 µg/L	F

All algae-risk lakes in Missouri →

Bloom-prone lakes in Indiana

No lakes with chlorophyll-a above 20 µg/L in our current dataset.

All algae-risk lakes in Indiana →

Bloom-prone lakes in North Dakota

Lake	Algae	Grade
Buffalo Lake Pierce County	219.5 µg/L	F
Juanita Lake Foster County	154.2 µg/L	F
Mchugh Slough Lake Nelson County	88.7 µg/L	F
Morrison Lake Ramsey County	85.9 µg/L	F
East Stump Lake Nelson County	75.3 µg/L	D
Kalmbach Lake LaMoure County	73.8 µg/L	F
Sweetbriar Dam Lake Morton County	54 µg/L	F
Cedar Lake Slope County	53.4 µg/L	F
Harmon Lake Morton County	48.5 µg/L	F
Antelope Lake Pierce County	43.6 µg/L	D
Sprague Lake Sargent County	43.4 µg/L	F
West Stump Lake Nelson County	39.6 µg/L	D
Eastern Stump Lake Nelson County	39.1 µg/L	F
Froelich Dam Lake Sioux County	37.5 µg/L	D
Sweet Briar Dam-Mid Reservoir Morton County	36.9 µg/L	F
Western Stump Lake Nelson County	36.7 µg/L	F
Dead Colt Creek Dam Lake Ransom County	32.3 µg/L	F
Mirror Lake Adams County	31.6 µg/L	F
Brewer Lake Cass County	31.1 µg/L	D
Odland Dam Lake Golden Valley County	29.6 µg/L	D
Warsing Dam Lake Eddy County	25.7 µg/L	D
Nygren Dam Lake Morton County	24.7 µg/L	D
Castle Rock Dam Lake Hettinger County	24.3 µg/L	D
Barnes Lake Stutsman County	24 µg/L	D
Nelson Lake Oliver County	23.1 µg/L	D

All algae-risk lakes in North Dakota →

Bloom-prone lakes in South Dakota

No lakes with chlorophyll-a above 20 µg/L in our current dataset.

All algae-risk lakes in South Dakota →

Bloom-prone lakes in Florida

Lake	Algae	Grade
Lake Okeechobee Martin County	22.8 µg/L	D

All algae-risk lakes in Florida →

Bloom-prone lakes in Colorado

Lake	Algae	Grade
Prospect Lake Weld County	42.5 µg/L	F

All algae-risk lakes in Colorado →

Bloom-prone lakes in North Carolina

Lake	Algae	Grade
Lake Mattamuskeet Hyde County	102.5 µg/L	D
Lake Lee Union County	90.5 µg/L	F
Lake Rogers Granville County	84.5 µg/L	F
Lake Tabor Columbus County	66 µg/L	D
Limestone Lake Duplin County	63 µg/L	D
Lake Monroe Union County	62 µg/L	F
Turner Reservoir Chatham County	59 µg/L	F
Rocky River Reservoir Chatham County	55.5 µg/L	F
Lake Twitty Union County	49 µg/L	D
Jordan Lake Chatham County	48.5 µg/L	F
Sandy Creek Reservoir Randolph County	44 µg/L	F
Graham-Mebane Reservoir Alamance County	44 µg/L	D
Harris Lake Wake County	43 µg/L	F
Lake Wilson Wilson County	41.5 µg/L	F
High Rock Lake Davidson County	41.5 µg/L	D
Lake Benson Wake County	40 µg/L	D
Lake Thom-A-Lex Davidson County	40 µg/L	D
Lake Wheeler Wake County	38 µg/L	D
Lake Orange Orange County	38 µg/L	D
Sycamore Lake Wake County	36.5 µg/L	D
Falls of the Neuse Reservoir Wake County	36 µg/L	D
Beaverdam Lake Wake County	36 µg/L	D
Town Creek Lake Rowan County	36 µg/L	D
B E Jordan Lake Chatham County	35.5 µg/L	D
Lake Crabtree Wake County	35.5 µg/L	F

All algae-risk lakes in North Carolina →

Bloom-prone lakes in Vermont

Lake	Algae	Grade
Shelburne Pond Chittenden County	50.5 µg/L	F
Jerome Lake Addison County	40.6 µg/L	F
Walker Pond Orleans County	20.7 µg/L	C
Lake Carmi Franklin County	20.2 µg/L	C

All algae-risk lakes in Vermont →

Bloom-prone lakes in Texas

Lake	Algae	Grade
Rita Blanca Lake Hartley County	345 µg/L	F
Lake Wichita Wichita County	159 µg/L	F
Palo Duro Reservoir Hansford County	139.6 µg/L	F
Springfield Lake Limestone County	129 µg/L	F
Lake Kirby Taylor County	124 µg/L	F
Lake Fryer Ochiltree County	124 µg/L	F
Somerville Lake Upper Portion Washington County	97.1 µg/L	F
Victor Braunig Lake Bexar County	91 µg/L	F
Buffalo Springs Lake Lubbock County	83.3 µg/L	F
Lake Weatherford Parker County	79.9 µg/L	D
Somerville Lake Washington County	77.9 µg/L	D
Lake Palestine Cwqmn Site Henderson County	68.9 µg/L	D
Lake Somerville Mid Lake Burleson County	68.7 µg/L	F
Somerville Lake Big Creek Arm Burleson County	67.7 µg/L	D
Lake Tanglewood Randall County	65.5 µg/L	F
Lake Murvaul Panola County	65.3 µg/L	D
Lake Cypress Springs Franklin County	64.5 µg/L	D
New Marlin City Lake Falls County	62 µg/L	F
Upper Lake Palestine Smith County	61.6 µg/L	D
Lewisville Lake Elm Fork Denton County	61.6 µg/L	D
Red Bluff Reserv Lake Loving County	60.3 µg/L	D
Lake Whitney Nolands River Arm Hill County	59.2 µg/L	D
Lake Opines Marion County	59.2 µg/L	D
White Rock Lake Dallas County	57.6 µg/L	D
Lake Palestine Smith County	56.5 µg/L	D

All algae-risk lakes in Texas →

Bloom-prone lakes in Oregon

Lake	Algae	Grade
Brownlee Reservoir Baker County	198 µg/L	F
Shoalwater Bay Lake Klamath County	147 µg/L	F
Cold Springs Reservoir Umatilla County	126 µg/L	F
Rattlesnake Point Lake Klamath County	124.5 µg/L	F
Upper Klamath Lake Klamath County	117 µg/L	F
Lake Billy Chinook Jefferson County	93.5 µg/L	F
Mid-North Lake Klamath County	82.7 µg/L	F
Mid-Trench Lake Klamath County	80.6 µg/L	F
Upper Klamath Lake Klamath County	71.6 µg/L	F
Williamson River Outlet Lake Klamath County	70.5 µg/L	F
Agency Lake South Klamath County	61.6 µg/L	F
Lake Billy Chinook Jefferson County	59.6 µg/L	F
Lake Billy Chinook Jefferson County	52.3 µg/L	F
Thief Valley Reservoir Union County	51.2 µg/L	F
Malheur Lake Harney County	45.5 µg/L	F
Diamond Lake Douglas County	42.6 µg/L	F
Cullaby Lake Clatsop County	36.8 µg/L	F
Deschutes River Arm Lake Jefferson County	33.1 µg/L	F
Tenmile Lake Coos County	30.6 µg/L	F
Lake Billy Chinook Jefferson County	24.6 µg/L	D
Crooked River Arm Lake Jefferson County	24.6 µg/L	D

All algae-risk lakes in Oregon →

Bloom-prone lakes in Arkansas

Lake	Algae	Grade
Bois D Arc Lake Hempstead County	138 µg/L	F
Grand Lake Chicot County	115.5 µg/L	F
Lake Hogue Poinsett County	114 µg/L	F
Lake June Lafayette County	99.5 µg/L	F
Lower Lake Chicot Chicot County	88.7 µg/L	F
Lake Pine Bluff Diagonally From North And East Levees Jefferson County	83.9 µg/L	F
Lake Conway Faulkner County	75.6 µg/L	F
Horseshoe Lake Crittenden County	72.6 µg/L	D
Lake Wallace Chicot County	72.5 µg/L	F
Lake Beulah Desha County	69.4 µg/L	F
Lower Lake Chicot Chicot County	59 µg/L	F
Overcup Lake Conway County	56.4 µg/L	D
Tunica Cutoff Lake Lee County	56.2 µg/L	F
Big Base Lake West Pulaski County	49.9 µg/L	C
Lake Atkins Pope County	49.5 µg/L	D
Lake Erling Lafayette County	49.2 µg/L	D
Lake Wilson Ashley County	47.9 µg/L	F
Desoto Lake Phillips County	44.1 µg/L	F
Lake Lee Chicot County	43.2 µg/L	F
Bear Creek Lake Lee County	42.9 µg/L	D
Lincoln Lake Washington County	41.6 µg/L	D
Lake Charles Lawrence County	40.9 µg/L	D
Storm Creek Lake Phillips County	40 µg/L	D
Blue Mountain Lake @ Ashley Creek Logan County	37.6 µg/L	F
Lake Fayetteville Washington County	36.4 µg/L	D

All algae-risk lakes in Arkansas →

Bloom-prone lakes in Oklahoma

Lake	Algae	Grade
Grand Lake Delaware County	384000 µg/L	F
Lake Texoma Johnston County	233 µg/L	F
Thunderbird Lake Nature Center Pottawatomie County	28.5 µg/L	C
Lake Thunderbird Cleveland County	28 µg/L	C
Coon Creek Lake Kay County	24 µg/L	D
Lake Texoma Marshall County	23 µg/L	D
Thunderbird Lake Fisherman'S Cleveland County	21.4 µg/L	C
Lake Texoma Bryan County	21 µg/L	C

All algae-risk lakes in Oklahoma →

Bloom-prone lakes in Kansas

Lake	Algae	Grade
Wakefield Boat Ramp Milford Lake Clay County	133000 µg/L	F
North Lake Clay County	76500 µg/L	F
Timber C Boat Ramp Milford Lake Clay County	1910 µg/L	F
Riggs Park Lake Sedgwick County	1700 µg/L	F
Colwich City Lake Sedgwick County	800 µg/L	F
Marais des Cygnes Wildlife Area Lake Linn County	602.2 µg/L	C
Carbondale West Lake Osage County	552.1 µg/L	F
Buhler City Lake Reno County	520 µg/L	F
Milford Lake Sugar Bowl Clay County	309 µg/L	F
Marais des Cygnes Nwr Lake Linn County	255 µg/L	F
Ellis City Lake Ellis County	250 µg/L	F
Lake Warnock Atchison County	219 µg/L	F
Harvey Co East Lake Harvey County	205 µg/L	F
Gathering Pond East Geary County	186 µg/L	F
Cheyenne Bottoms Pool Barton County	173.5 µg/L	F
Ogden City Lake Riley County	168.5 µg/L	F
Garnett Lake Anderson County	160 µg/L	D
Little Lake Brown County	155 µg/L	F
Jamestown Wildlife Area Lake Cloud County	150 µg/L	F
Kingman Co State Fishing Lake Kingman County	150 µg/L	F
Fossil Lake Russell County	142 µg/L	C
Harvey County Camp Hawk Lake Harvey County	138.4 µg/L	F
Newton City Park Lake Harvey County	120 µg/L	F
Harvey Co West Park Lake Harvey County	118.4 µg/L	D
Pratt County Lake Pratt County	110 µg/L	F

All algae-risk lakes in Kansas →

Bloom-prone lakes in Nebraska

Lake	Algae	Grade
Crescent Lake Garden County	118.4 µg/L	F
Merritt Reservoir Cherry County	94.2 µg/L	F
Pelican Lake Cherry County	88.9 µg/L	F
Wildwood Lake Lancaster County	85.8 µg/L	F
Grove Lake Antelope County	84.8 µg/L	D
Willow Creek Reservoir Pierce County	78.4 µg/L	F
Carter Lake Douglas County	76 µg/L	F
Swan Lake Holt County	74.8 µg/L	F
Willow Creek Reservoir Sarpy County	66.4 µg/L	D
Burchard Lake Pawnee County	65.3 µg/L	F
Maskenthine Reservoir Stanton County	62.9 µg/L	F
Memphis Lake Saunders County	62.6 µg/L	F
Lake Hastings Adams County	60.5 µg/L	F
Smith Lake Sheridan County	56.1 µg/L	F
Swan Creek Lake Saline County	55.4 µg/L	F
Pibel Lake Wheeler County	54.9 µg/L	F
Czechland Lake Saunders County	53.4 µg/L	F
Meadowlark Lake Seward County	49.8 µg/L	F
Qacnelakedup Douglas County	47 µg/L	D
Hedgefield Lake Lancaster County	46.9 µg/L	F
Homestead Lake Butler County	46.7 µg/L	F
Liberty Cove Lake Webster County	44.1 µg/L	F
Carter Lake Max Depth Douglas County	42.9 µg/L	F
Big Indian Lake Gage County	42.1 µg/L	F
Summit Lake Burt County	38.4 µg/L	D

All algae-risk lakes in Nebraska →

Bloom-prone lakes in Nevada

Lake	Algae	Grade
Willow Creek Reservoir East Elko County	4013.5 µg/L	F
Wildhorse Res South Basin Lake Elko County	158 µg/L	D
Wildhorse Reservoir Elko County	76 µg/L	F
Sheep Creek Middle Reservoir Elko County	63.7 µg/L	F
Mountain View Lake Elko County	49.5 µg/L	D
Spooner Lake Douglas County	40.6 µg/L	D
Knott Creek Reservoir Humboldt County	32.5 µg/L	D
Wildhorse Res North Basin Lake Elko County	20.2 µg/L	D

All algae-risk lakes in Nevada →

Bloom-prone lakes in Arizona

No lakes with chlorophyll-a above 20 µg/L in our current dataset.

All algae-risk lakes in Arizona →

Bloom-prone lakes in Idaho

Lake	Algae	Grade
Mann Creek Reservoir Washington County	179 µg/L	D
Little Wood Reservoir Blaine County	30.5 µg/L	D
American Falls R-Sportsmans Cove Lake Power County	20.1 µg/L	C

All algae-risk lakes in Idaho →

Bloom-prone lakes in Montana

Lake	Algae	Grade
Boneau Reservoir Chouteau County	39 µg/L	D

All algae-risk lakes in Montana →

Bloom-prone lakes in New Mexico

Lake	Algae	Grade
Bluewater Lake Cibola County	112.3 µg/L	F
Six Mile Dam Lake Eddy County	110.3 µg/L	F
Jal Lake Lea County	62.3 µg/L	D
Hopewell Lake Rio Arriba County	52.9 µg/L	D
Lake Roberts Grant County	41.1 µg/L	F
Caballo Lake Sierra County	37.4 µg/L	D
Burns Lake Deep Rio Arriba County	23.5 µg/L	D
Quemado Dam Lake Catron County	23.1 µg/L	D
Brantley Reservoir Deep Eddy County	21 µg/L	D
Elephant Butte Reservoir Sierra County	20.8 µg/L	D

All algae-risk lakes in New Mexico →

Bloom-prone lakes in Tennessee

No lakes with chlorophyll-a above 20 µg/L in our current dataset.

All algae-risk lakes in Tennessee →

Bloom-prone lakes in Alabama

Lake	Algae	Grade
Bvlj Lake Jefferson County	40.3 µg/L	F
Nees Lake Etowah County	30.3 µg/L	C
Ogll Lake Lee County	26.7 µg/L	C
Nees Lake St. Clair County	25.4 µg/L	C
Nees Lake Cherokee County	24 µg/L	C
Logs Lake Talladega County	22.2 µg/L	C
Weic Lake Cherokee County	21.4 µg/L	C
Warg Lake Hale County	21.3 µg/L	C
Logs Lake St. Clair County	20.6 µg/L	C

All algae-risk lakes in Alabama →

Bloom-prone lakes in Virginia

Lake	Algae	Grade
Ut To Chk Lake Hanover County	63.3 µg/L	F
North Anna River Lake Spotsylvania County	59.5 µg/L	F
Bryants Pond Sussex County	49.6 µg/L	F
Upper Branch of Terry'S Run Lake Spotsylvania County	33.4 µg/L	D
Brunswick County Lake Brunswick County	28.6 µg/L	C
Lake Nelson Nelson County	27.7 µg/L	C
Fluvanna Ruritan Lake Fluvanna County	27.5 µg/L	C
Lake Chesdin Chesterfield County	25.9 µg/L	D
Lake Culpeper Culpeper County	24.9 µg/L	C
Falling Creek Lake Chesterfield County	22.9 µg/L	C
Totier Creek Reservoir Albemarle County	20.8 µg/L	C
Lake Anna Spotsylvania County	20.6 µg/L	C
Powhatan Lake Powhatan County	20.5 µg/L	C

All algae-risk lakes in Virginia →

Bloom-prone lakes in Kentucky

No lakes with chlorophyll-a above 20 µg/L in our current dataset.

All algae-risk lakes in Kentucky →

Bloom-prone lakes in Utah

Lake	Algae	Grade
Utah Lake Utah County	159.3 µg/L	F
Utah Lake Utah County	145.2 µg/L	F
Utah Lake Utah County	95.8 µg/L	F
Farmington Bay Lake Davis County	89.9 µg/L	F
Newcastle Reservoir Iron County	89 µg/L	D
Koosharem Reservoir Sevier County	58.4 µg/L	D
Utah Lake Utah County	55.1 µg/L	F
Utah Lake Goshen Bay Southwest End Utah County	49.6 µg/L	F
Newcastle Reservoir Midway Iron County	46 µg/L	D
Utah Lake Outside Entrance To Provo Bay Utah County	40.8 µg/L	F
Mantua Reservoir Box Elder County	39.7 µg/L	F
Yuba Reservoir Midway Juab County	38.4 µg/L	F
Baker Dam Reservoir Washington County	29.5 µg/L	D
Johnson Reservoir Sevier County	29.1 µg/L	D
Gsl Farmington Bay Outflow Lake Davis County	26 µg/L	F
Mantua Reservoir S Box Elder County	23.4 µg/L	D
Mill Meadow Reservoir Wayne County	22.7 µg/L	D
Panguitch L Shore Lake Garfield County	21.7 µg/L	D

All algae-risk lakes in Utah →

Bloom-prone lakes in Washington

Lake	Algae	Grade
Lake Thurston County	34 µg/L	F
Vancouver Lake Clark County	27.9 µg/L	D

All algae-risk lakes in Washington →

Bloom-prone lakes in Wyoming

No lakes with chlorophyll-a above 20 µg/L in our current dataset.

All algae-risk lakes in Wyoming →

Bloom-prone lakes in Georgia

Lake	Algae	Grade
High Falls Lake Monroe County	23 µg/L	D

All algae-risk lakes in Georgia →

Bloom-prone lakes in Massachusetts

Lake	Algae	Grade
Wedge Pond Middlesex County	70.4 µg/L	F
Billerica Impoundment Lake Middlesex County	68.6 µg/L	F
Barkers Pond Middlesex County	54.5 µg/L	F
Santuit Pond Barnstable County	52.4 µg/L	F
Cooks Pond Plymouth County	48.4 µg/L	F
Furnace Pond Plymouth County	46.8 µg/L	F
Upper Artichoke Reservoir Essex County	44 µg/L	F
Gleasons Pond Middlesex County	43.9 µg/L	F
South Watuppa Pond Bristol County	43.3 µg/L	F
Bartlett Pond Worcester County	37.5 µg/L	F
Spy Pond Middlesex County	33.6 µg/L	F
Nashawannuck Pond Hampshire County	32.4 µg/L	F
Mill Pond Barnstable County	30.5 µg/L	F
Little Chauncy Pond Worcester County	30 µg/L	F
Pequot Pond Hampden County	27.5 µg/L	D
Ten Mile River Lake Bristol County	22.1 µg/L	D

All algae-risk lakes in Massachusetts →

If you see a bloom

Do not swim or let pets enter the water.
Do not drink, cook with, or boil the water (boiling concentrates the toxins).
Rinse off immediately with clean water if exposed.
Report the bloom to your state environmental agency (e.g. MN PCA at health.algae@state.mn.us, or WI DNR).
Watch dogs closely after lake exposure — symptoms can appear within 30-60 minutes.

What causes algae blooms? →What is blue-green algae? →Are lakes safe for dogs? →Full algae blooms guide →