Blue-Green Algae Bloom Tracker
No lake in the United States (49 states), Canada (Ontario, Québec, Nova Scotia, British Columbia and Newfoundland and Labrador), and 38 other country hubs. we cover is showing an elevated blue-green algae reading in EPA CyAN satellite data from the last four weeks. Blue-green algae (cyanobacteria) can produce toxins that are dangerous to people and fatal to dogs, so keep out of any water with visible scum and check your state’s current advisory before you swim.
Bloom-prone lakes by state
Lakes most likely to develop blue-green algae (cyanobacteria) blooms across our 41 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 |
|---|---|---|
| Olson Lake Big Stone County | 384 µg/L | NR |
| Cowley Lake Hennepin County | 343.5 µg/L | F |
| Domeier Lake Brown County | 332 µg/L | NR |
| Unnamed Lake Brown County | 300 µg/L | NR |
| Alice Lake Otter Tail County | 254 µg/L | F |
| Maria Lake Carver County | 249.5 µg/L | F |
| Uhlenkolts Lake Stearns County | 205 µg/L | F |
| Talcot Lake Cottonwood County | 193 µg/L | NR |
| Fountain Lake Wright County | 174 µg/L | F |
| Clear Lake Stevens County | 171 µg/L | NR |
| Mccarthy Lake Dakota County | 169.5 µg/L | F |
| Snyder Lake Hennepin County | 164 µg/L | NR |
| Goose Lake Carver County | 160.5 µg/L | F |
| Otrey Lake Big Stone County | 156 µg/L | NR |
| Barry Lake Big Stone County | 149 µg/L | NR |
| Bella Lake Nobles County | 145 µg/L | NR |
| Unnamed Lake Watonwan County | 142 µg/L | NR |
| Saint Johns Lake Kandiyohi County | 140 µg/L | NR |
| Hope Lake Meeker County | 140 µg/L | NR |
| Goose Lake Ramsey County | 139 µg/L | F |
| Hazeltine Lake Carver County | 136.5 µg/L | F |
| Ardmore Lake Hennepin County | 130 µg/L | F |
| Augusta Lake Dakota County | 130 µg/L | F |
| Mud Lake Hennepin County | 123.5 µg/L | F |
| Omsrud Lake Brown County | 120 µg/L | NR |
Bloom-prone lakes in Wisconsin
No lakes with chlorophyll-a above 20 µg/L in our current dataset.
All algae-risk lakes in Wisconsin →Bloom-prone lakes in Illinois
| Lake | Algae | Grade |
|---|---|---|
| Quiver Lake Mason County | 140 µg/L | NR |
| Island Lake McHenry County | 136.5 µg/L | F |
| Boujan Swale Lake Cass County | 136 µg/L | NR |
| Bullfrog Lake Cook County | 124.5 µg/L | F |
| Kinmundy Old Lake Marion County | 114.8 µg/L | F |
| Saganashkee Slough Lake Cook County | 108.5 µg/L | F |
| Slm Side Channel Lake St. Clair County | 95.6 µg/L | F |
| Sam Dale Lake Wayne County | 95.2 µg/L | F |
| Governor Bond Lake Bond County | 91 µg/L | F |
| Slocum Lake Lake County | 90.3 µg/L | F |
| Nashville City Lake Washington County | 89.3 µg/L | F |
| Mermet Lake Massac County | 88.5 µg/L | F |
| Mattoon Lake Cumberland County | 87.1 µg/L | F |
| Vandalia Lake Fayette County | 84.4 µg/L | F |
| Louise Lake Lake County | 80.2 µg/L | F |
| Salem Lake Marion County | 77.5 µg/L | F |
| Forbes Lake Marion County | 75.9 µg/L | F |
| Skokie Lagoons Lake Cook County | 74.7 µg/L | F |
| Raccoon Lake Marion County | 73.5 µg/L | F |
| Lou Yaeger Lake Montgomery County | 72.6 µg/L | F |
| Glenn Shoals Lake Montgomery County | 72.1 µg/L | F |
| Centralia Lake Marion County | 69.7 µg/L | F |
| Paradise Lake Pike County | 68.5 µg/L | F |
| Diamond Lake Lake County | 63.6 µg/L | F |
| Mauvaise Terre Lake Morgan County | 62 µg/L | F |
Bloom-prone lakes in Michigan
| Lake | Algae | Grade |
|---|---|---|
| Community College Pond Chippewa County | 37.3 µg/L | F |
| South Pond Chippewa County | 25.4 µg/L | D |
| Palmer Lake St. Joseph County | 21 µg/L | D |
| Lake Diane Hillsdale County | 20 µg/L | D |
Bloom-prone lakes in Iowa
| Lake | Algae | Grade |
|---|---|---|
| Cedar Lake Linn County | 125.4 µg/L | F |
| Hannen Lake Benton County | 119.9 µg/L | F |
| Meyers Lake Black Hawk County | 116.5 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 |
| Lake Orient Adair County | 92.2 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 |
Bloom-prone lakes in Ohio
All algae-risk lakes in Ohio →Bloom-prone lakes in Pennsylvania
| Lake | Algae | Grade |
|---|---|---|
| Speedwell Forge Dam Lancaster County | 89.3 µg/L | D |
| Middle Creek Reservoir Lancaster County | 74.1 µg/L | F |
| Colyer Lake Centre County | 72 µg/L | F |
| Edinboro Lake Erie County | 48 µg/L | C |
| Lake Luxembourg Bucks County | 46.4 µg/L | F |
| Green Lane Reservoir Montgomery County | 45.6 µg/L | F |
| Struble Lake Chester County | 45.3 µg/L | F |
| Harris Pond Luzerne County | 44.5 µg/L | F |
| Lake Nessmuk Tioga County | 41.2 µg/L | D |
| Shawnee Lake Bedford County | 37.4 µg/L | F |
| Walker Lake Snyder County | 36.4 µg/L | F |
| Moon Lake Luzerne County | 35.5 µg/L | NR |
| Canonsburg Lake Washington County | 35.4 µg/L | F |
| Foster Joseph Sayers Lake Centre County | 34.7 µg/L | F |
| Beechwood Lake Tioga County | 32.3 µg/L | D |
| Minks Pond Pike County | 30.7 µg/L | NR |
| Black Moshannon Lake Centre County | 25.4 µg/L | C |
| Shohola Marsh Reservoir Pike County | 23.4 µg/L | NR |
| Lake Chillisquaque Montour County | 23 µg/L | D |
| Fords Lake Lackawanna County | 20.5 µg/L | D |
| Opossum Lake Cumberland County | 20.1 µg/L | C |
Bloom-prone lakes in New York
No lakes with chlorophyll-a above 20 µg/L in our current dataset.
All algae-risk lakes in New York →Bloom-prone lakes in Missouri
| Lake | Algae | Grade |
|---|---|---|
| Knox Village Lake Jackson County | 193.5 µg/L | NR |
| Crowder S.P. Lake Grundy County | 176.4 µg/L | NR |
| Limpp Lake Gentry County | 166.5 µg/L | NR |
| Drexel City Reservoir South Bates County | 152.7 µg/L | F |
| Lewis Lake Stoddard County | 149.8 µg/L | NR |
| Izaak Walton Lake Vernon County | 123.1 µg/L | NR |
| Loose Park Lake Jackson County | 118.7 µg/L | F |
| Edwin A Pape Lake Lafayette County | 116.6 µg/L | NR |
| 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 | NR |
| Lake Luna Cass County | 92.7 µg/L | F |
| Hemitite Lake St. Francois County | 91.9 µg/L | F |
| Chaumiere Lake Clay County | 86 µg/L | NR |
| Valley Lake Jackson County | 84.4 µg/L | F |
| Sterling Price Lake Chariton County | 78.8 µg/L | F |
| Chaumiere Park Lake Clay County | 76.3 µg/L | F |
| Troost Lake Jackson County | 75.3 µg/L | F |
| Lake St Louis St. Charles County | 74.3 µg/L | NR |
| Mckee Prairie Pond Jackson County | 71.7 µg/L | F |
| Firehouse Park Lake Jackson County | 68 µg/L | F |
| Nell Lake Jackson County | 67 µg/L | F |
| Tilles Park Reservoir St. Louis County | 66.5 µg/L | NR |
| Harrisonville Lake Cass County | 66 µg/L | NR |
| Blue River Parkway Lake Jackson County | 64.2 µg/L | F |
Bloom-prone lakes in Indiana
| Lake | Algae | Grade |
|---|---|---|
| Mollenkramer Reservoir Ripley County | 128.4 µg/L | NR |
| Riddles Lake St. Joseph County | 92.3 µg/L | NR |
| Long Lake Noble County | 87.5 µg/L | NR |
| Lake Sullivan Sullivan County | 79.3 µg/L | D |
| Pleasant Lake St. Joseph County | 72.1 µg/L | D |
| Muncie Lake Noble County | 66.3 µg/L | NR |
| Bischoff Reservoir Ripley County | 63.4 µg/L | NR |
| Big Bass Lake Porter County | 62.5 µg/L | F |
| Rivir Lake Noble County | 57 µg/L | NR |
| Sylvan Lake Noble County | 55.5 µg/L | NR |
| Palestine Lake Kosciusko County | 54.5 µg/L | D |
| Troy Cedar Lake Whitley County | 49.1 µg/L | NR |
| Skinner Lake Noble County | 43 µg/L | F |
| Lake Holiday Lake County | 42.5 µg/L | F |
| Flat Lake Marshall County | 40.7 µg/L | NR |
| Huntington Lake Huntington County | 40.3 µg/L | D |
| Lake George Lake County | 40.1 µg/L | NR |
| Norman Lake Noble County | 36.6 µg/L | NR |
| Waldron Lake Noble County | 36.2 µg/L | F |
| Mississinewa Lake Wabash County | 35.5 µg/L | F |
| Ferdinand State Forest Lake Dubois County | 35.3 µg/L | NR |
| Diamond Lake Kosciusko County | 35 µg/L | NR |
| Whitewater Lake Union County | 34.4 µg/L | NR |
| Loon Lake Kosciusko County | 30.5 µg/L | NR |
| Nauvoo Lake LaGrange County | 30.3 µg/L | NR |
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 | NR |
| Mchugh Slough Lake Nelson County | 88.7 µg/L | F |
| Morrison Lake Ramsey County | 85.9 µg/L | F |
| Kalmbach Lake LaMoure County | 73.8 µg/L | NR |
| Sweetbriar Dam Lake Morton County | 54 µg/L | F |
| Cedar Lake Slope County | 53.4 µg/L | C |
| Harmon Lake Morton County | 48.5 µg/L | F |
| Antelope Lake Pierce County | 43.6 µg/L | F |
| Sprague Lake Sargent County | 43.4 µg/L | NR |
| Eastern Stump Lake Nelson County | 39.1 µg/L | F |
| East Stump Lake Nelson County | 37.9 µg/L | NR |
| 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 | NR |
| Mirror Lake Adams County | 31.6 µg/L | F |
| Brewer Lake Cass County | 31.1 µg/L | NR |
| 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 | NR |
| Nelson Lake Oliver County | 23.1 µg/L | C |
| Lake Laretta Nelson County | 21.7 µg/L | D |
Bloom-prone lakes in South Dakota
| Lake | Algae | Grade |
|---|---|---|
| Indian Slough Roberts County | 136.1 µg/L | NR |
| Lake Isabella Marshall County | 86.9 µg/L | NR |
| Rehfeldt Slough Minnehaha County | 82.4 µg/L | NR |
| Meiers Lake Bon Homme County | 66.9 µg/L | NR |
| Big Stone Lake Roberts County | 23.6 µg/L | D |
Bloom-prone lakes in Florida
No lakes with chlorophyll-a above 20 µg/L in our current dataset.
All algae-risk lakes in Florida →Bloom-prone lakes in Colorado
| Lake | Algae | Grade |
|---|---|---|
| North Sterling Reservoir Logan County | 198.1 µg/L | F |
| Turks Pond Baca County | 139.7 µg/L | NR |
| Prospect Lake El Paso County | 80.5 µg/L | F |
| Prospect Lake Weld County | 42.5 µg/L | F |
| Equestrian Park Pond Douglas County | 35.7 µg/L | NR |
| Berkeley Lake Denver County | 34.1 µg/L | NR |
| Prewitt Reservoir Washington County | 31.5 µg/L | NR |
| Horse Creek Outlet Lake Weld County | 27.6 µg/L | D |
| Windsor Lake Weld County | 25.4 µg/L | D |
| Jackson Reservoir Morgan County | 22.3 µg/L | D |
| Adobe Creek Reservoir Bent County | 21.7 µg/L | NR |
Bloom-prone lakes in North Carolina
| Lake | Algae | Grade |
|---|---|---|
| Lake Mattamuskeet Hyde County | 102.5 µg/L | F |
| Lake Lee Union County | 90.5 µg/L | F |
| Sunset Lake Wake County | 72 µg/L | F |
| Lake Tabor Columbus County | 66 µg/L | F |
| Limestone Lake Duplin County | 63 µg/L | F |
| Lake Monroe Union County | 62 µg/L | F |
| Lake Rogers Granville County | 60.5 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 | F |
| Jordan Lake Chatham County | 46 µg/L | F |
| Graham-Mebane Reservoir Alamance County | 44 µg/L | F |
| Lake Wilson Wilson County | 43.5 µg/L | F |
| Harris Lake Wake County | 43 µg/L | F |
| Sandy Creek Reservoir Randolph County | 41.5 µg/L | F |
| High Rock Lake Davidson County | 41.5 µg/L | F |
| Wake Forest Reservoir @ Dam Wake County | 41 µg/L | NR |
| Lake Thom-A-Lex Davidson County | 40 µg/L | F |
| Lake Orange Orange County | 38 µg/L | F |
| Lake Benson Wake County | 38 µg/L | F |
| Big Lake Wake County | 37 µg/L | F |
| Lake Michie Durham County | 36 µg/L | F |
| Falls of the Neuse Reservoir Wake County | 36 µg/L | F |
| Town Creek Lake Rowan County | 36 µg/L | F |
| B E Jordan Lake Chatham County | 35.5 µg/L | F |
Bloom-prone lakes in Vermont
| Lake | Algae | Grade |
|---|---|---|
| Shelburne Pond Chittenden County | 51.5 µg/L | F |
| Jerome Lake Addison County | 40.6 µg/L | NR |
| Lake Carmi Franklin County | 20.3 µg/L | D |
Bloom-prone lakes in Texas
| Lake | Algae | Grade |
|---|---|---|
| Rita Blanca Lake Hartley County | 345 µg/L | NR |
| Palo Duro Reservoir Hansford County | 139.6 µg/L | NR |
| Springfield Lake Limestone County | 129 µg/L | F |
| Lake Kirby Taylor County | 124 µg/L | F |
| Lake Fryer Ochiltree County | 124 µg/L | F |
| Victor Braunig Lake Bexar County | 91 µg/L | NR |
| Buffalo Springs Lake Lubbock County | 83.3 µg/L | F |
| Lake Weatherford Parker County | 79.9 µg/L | F |
| Lake Somerville Mid Lake Burleson County | 68.7 µg/L | F |
| Somerville Lake Big Creek Arm Burleson County | 67.7 µg/L | F |
| Lake Tanglewood Randall County | 65.5 µg/L | F |
| Lake Murvaul Panola County | 65.3 µg/L | F |
| New Marlin City Lake Falls County | 62 µg/L | F |
| Upper Lake Palestine Smith County | 61.6 µg/L | F |
| Lake Whitney Nolands River Arm Hill County | 59.2 µg/L | F |
| Lake Opines Marion County | 59.2 µg/L | F |
| White Rock Lake Dallas County | 57.6 µg/L | F |
| Lake Palestine Smith County | 56.5 µg/L | F |
| L Houston W of Lake Shadows Harris County | 56.1 µg/L | NR |
| Lake Mexia Limestone County | 50.7 µg/L | F |
| Lake Crook Mid Lake Lamar County | 50 µg/L | F |
| Lake Cypress Springs Mid Lake Franklin County | 49.5 µg/L | F |
| Lavon Lake Collin County | 48 µg/L | F |
| Lake Kiowa Cooke County | 47 µg/L | NR |
| Pat Cleburne Reservoir Johnson County | 46.9 µg/L | F |
Bloom-prone lakes in Oregon
| Lake | Algae | Grade |
|---|---|---|
| Shoalwater Bay Lake Klamath County | 143.5 µg/L | F |
| Cold Springs Reservoir Umatilla County | 126 µg/L | F |
| Rattlesnake Point Lake Klamath County | 124.5 µg/L | F |
| Brownlee Reservoir Baker County | 108 µg/L | F |
| Mid-North Lake Klamath County | 81.1 µg/L | F |
| Mid-Trench Lake Klamath County | 80.6 µg/L | F |
| Williamson River Outlet Lake Klamath County | 67.9 µg/L | F |
| Agency Lake South Klamath County | 61.6 µg/L | F |
| Thief Valley Reservoir Union County | 51.2 µg/L | F |
| Mckay Lake Umatilla County | 49.4 µg/L | NR |
| Malheur Lake Harney County | 45.5 µg/L | F |
| Diamond Lake Douglas County | 43.4 µg/L | F |
| Cullaby Lake Clatsop County | 36.8 µg/L | F |
| Tenmile Lake Coos County | 30.6 µg/L | F |
| Lake Billy Chinook Deschutes R Arm @ Floating Station Jefferson County | 27.7 µg/L | D |
| Crooked River Arm Lake Jefferson County | 24.6 µg/L | D |
Bloom-prone lakes in Arkansas
| Lake | Algae | Grade |
|---|---|---|
| Bois D Arc Lake Hempstead County | 137 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 |
| 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 | F |
| 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 | F |
| Tunica Cutoff Lake Lee County | 56.2 µg/L | F |
| Big Base Lake West Pulaski County | 49.9 µg/L | NR |
| Lake Atkins Pope County | 49.5 µg/L | F |
| Lake Erling Lafayette County | 49.2 µg/L | F |
| 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 | NR |
| Bear Creek Lake Lee County | 42.9 µg/L | F |
| Lincoln Lake Washington County | 41.6 µg/L | F |
| Lake Charles Lawrence County | 40.9 µg/L | F |
| Storm Creek Lake Phillips County | 40 µg/L | F |
| Blue Mountain Lake @ Ashley Creek Logan County | 37.6 µg/L | NR |
| Crystal Lake Benton County | 35.3 µg/L | F |
| Siloam Springs Lake Benton County | 34.4 µg/L | F |
Bloom-prone lakes in Oklahoma
| Lake | Algae | Grade |
|---|---|---|
| Lake Texoma Johnston County | 233 µg/L | NR |
| Lake Thunderbird Cleveland County | 28.7 µg/L | D |
| Thunderbird Lake Nature Center Pottawatomie County | 28.5 µg/L | NR |
| 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 | D |
Bloom-prone lakes in Kansas
| Lake | Algae | Grade |
|---|---|---|
| Marais des Cygnes Wildlife Area Lake Linn County | 454 µg/L | NR |
| Marais des Cygnes Nwr Lake Linn County | 255 µg/L | NR |
| 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 | NR |
| Gathering Pond East Geary County | 189 µg/L | NR |
| Cheyenne Bottoms Pool Barton County | 173.5 µg/L | F |
| Ogden City Lake Riley County | 168.5 µg/L | NR |
| Garnett Lake Anderson County | 160 µg/L | NR |
| Little Lake Brown County | 155 µg/L | NR |
| Jamestown Wildlife Area Lake Cloud County | 150 µg/L | F |
| Kingman Co State Fishing Lake Kingman County | 150 µg/L | NR |
| Fossil Lake Russell County | 142 µg/L | NR |
| Harvey County Camp Hawk Lake Harvey County | 138.4 µg/L | NR |
| Newton City Park Lake Harvey County | 120 µg/L | NR |
| Harvey Co West Park Lake Harvey County | 118.4 µg/L | F |
| Pratt County Lake Pratt County | 110 µg/L | NR |
| Water Works Park Lake Johnson County | 107 µg/L | F |
| Central Park Lake Shawnee County | 105 µg/L | F |
| Spring Creek Park Lake Douglas County | 104.6 µg/L | NR |
| Mcpherson Co State Fishing Lake McPherson County | 100 µg/L | NR |
| Chisholm Creek Park Lake South Sedgwick County | 97 µg/L | NR |
| Chanute Santa Fe Lake Neosho County | 95.5 µg/L | F |
| Summer Crest Park Lake Johnson County | 93.5 µg/L | NR |
| Hiawatha City Lake Brown County | 93 µg/L | F |
Bloom-prone lakes in Nebraska
| Lake | Algae | Grade |
|---|---|---|
| Crescent Lake Garden County | 109.6 µg/L | B |
| Merritt Reservoir Cherry County | 92.1 µg/L | B |
| Pelican Lake Cherry County | 88.9 µg/L | B |
| Wildwood Lake Lancaster County | 85.8 µg/L | F |
| Grove Lake Antelope County | 84.8 µg/L | F |
| Willow Creek Reservoir Pierce County | 78.4 µg/L | NR |
| Carter Lake Douglas County | 76 µg/L | NR |
| Swan Lake Holt County | 74.8 µg/L | B |
| Willow Creek Reservoir Sarpy County | 65.6 µg/L | F |
| 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 | NR |
| Lake Hastings Adams County | 60.5 µg/L | NR |
| Smith Lake Sheridan County | 56.1 µg/L | B |
| Swan Creek Lake Saline County | 55.4 µg/L | F |
| Pibel Lake Wheeler County | 54.9 µg/L | C |
| Czechland Lake Saunders County | 53.4 µg/L | NR |
| Meadowlark Lake Seward County | 49.8 µg/L | F |
| Hedgefield Lake Lancaster County | 46.9 µg/L | F |
| Homestead Lake Butler County | 46.7 µg/L | NR |
| Liberty Cove Lake Webster County | 44.1 µg/L | F |
| Big Indian Lake Gage County | 42.1 µg/L | F |
| Summit Lake Burt County | 37.7 µg/L | F |
| Lone Star Reservoir Fillmore County | 36.5 µg/L | F |
| Gallagher Canyon Reservoir Dawson County | 35.6 µg/L | NR |
Bloom-prone lakes in Nevada
| Lake | Algae | Grade |
|---|---|---|
| Wildhorse Reservoir Elko County | 67.2 µg/L | F |
| Sheep Creek Middle Reservoir Elko County | 63.7 µg/L | NR |
| Knott Creek Reservoir Humboldt County | 59 µg/L | F |
| Spooner Lake Douglas County | 40.6 µg/L | C |
| Willow Creek Reservoir East Elko County | 27 µg/L | NR |
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 | NR |
| Little Wood Reservoir Blaine County | 30.2 µg/L | NR |
| Soldier Meadow Reservoir East Arm Nez Perce County | 29 µg/L | NR |
| Soldiers Meadow Reservoir West Arm Nez Perce County | 28.5 µg/L | NR |
Bloom-prone lakes in Montana
| Lake | Algae | Grade |
|---|---|---|
| Boneau Reservoir Chouteau County | 39 µg/L | F |
Bloom-prone lakes in New Mexico
| Lake | Algae | Grade |
|---|---|---|
| Six Mile Dam Lake Eddy County | 110.3 µg/L | NR |
| Jal Lake Lea County | 62.3 µg/L | NR |
| Hopewell Lake Rio Arriba County | 52.9 µg/L | F |
| Lake Roberts Grant County | 41.1 µg/L | NR |
| Caballo Lake Sierra County | 37.4 µg/L | F |
| Burns Lake Deep Rio Arriba County | 23.5 µg/L | NR |
| Brantley Reservoir Deep Eddy County | 21 µg/L | NR |
| Elephant Butte Reservoir Sierra County | 20.8 µg/L | NR |
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 |
| Ogll Lake Lee County | 26.7 µg/L | D |
| Nees Lake St. Clair County | 25.4 µg/L | D |
| Nees Lake Cherokee County | 24 µg/L | D |
| Logs Lake Talladega County | 22.2 µg/L | D |
| Weic Lake Cherokee County | 21.4 µg/L | D |
| Warg Lake Hale County | 21.3 µg/L | C |
Bloom-prone lakes in Virginia
| Lake | Algae | Grade |
|---|---|---|
| Station Lake Virginia Beach city County | 85.9 µg/L | F |
| Sta Lake Virginia Beach city County | 85.6 µg/L | F |
| Ut To Chk Lake Hanover County | 63.3 µg/L | D |
| North Anna River Lake Spotsylvania County | 59.5 µg/L | NR |
| Bryants Pond Sussex County | 49.6 µg/L | D |
| Swift Creek Lake Sta Chesterfield County | 35 µg/L | F |
| Near Dam Lake Cumberland County | 33.6 µg/L | F |
| Upper Branch of Terry'S Run Lake Spotsylvania County | 33.4 µg/L | F |
| Fluvanna Ruritan Lake Fluvanna County | 30 µg/L | D |
| Lake Nelson Nelson County | 29.3 µg/L | D |
| Brunswick County Lake Brunswick County | 28.6 µg/L | D |
| Speights Run Suffolk city County | 25.8 µg/L | C |
| Totier Creek Reservoir Albemarle County | 25.8 µg/L | D |
| Falling Creek Lake Chesterfield County | 25.7 µg/L | NR |
| Lake Culpeper Culpeper County | 24.9 µg/L | D |
| At Dam Lake Albemarle Albemarle County | 24.1 µg/L | D |
| Powhatan Lake Powhatan County | 23.4 µg/L | D |
| Lake Anna Spotsylvania County | 21.2 µg/L | D |
| Station Lake Suffolk city County | 20.9 µg/L | C |
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 |
|---|---|---|
| Farmington Bay Lake Davis County | 106 µg/L | F |
| Newcastle Reservoir Iron County | 89 µg/L | C |
| Koosharem Reservoir Sevier County | 58.4 µg/L | F |
| Utah Lake Sp @ Marina Utah County | 55.3 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 | 27.8 µg/L | D |
| Mill Meadow Reservoir Wayne County | 22.7 µg/L | D |
| Panguitch L Shore Lake Garfield County | 21.7 µg/L | D |
Bloom-prone lakes in Washington
| Lake | Algae | Grade |
|---|---|---|
| Lake Thurston County | 34 µg/L | F |
| Vancouver Lake Clark County | 28.6 µg/L | NR |
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 |
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 | NR |
| Barkers Pond Middlesex County | 54.5 µg/L | F |
| Santuit Pond Barnstable County | 52.4 µg/L | NR |
| Cooks Pond Plymouth County | 48.4 µg/L | F |
| Furnace Pond Plymouth County | 46.8 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 |
| 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 | D |
| Upper Artichoke Reservoir Essex County | 29.2 µg/L | D |
| Pequot Pond Hampden County | 27.5 µg/L | D |
Bloom-prone lakes in Ontario
No lakes with chlorophyll-a above 20 µg/L in our current dataset.
All algae-risk lakes in Ontario →Bloom-prone lakes in Québec
| Lake | Algae | Grade |
|---|---|---|
| Lac Bleu Rouville County | 82.4 µg/L | NR |
| Petit Lac Saint-FrançOis Le Val-Saint-François County | 77.8 µg/L | NR |
| Lac Saint-Charles Bellechasse County | 69.7 µg/L | NR |
| Lac à Vaillancourt Rimouski-Neigette County | 56.4 µg/L | NR |
| Lac Roxton La Haute-Yamaska County | 36.4 µg/L | NR |
| Lac Mandeville D'Autray County | 34 µg/L | NR |
| Lac de la Belle Montagne Matawinie County | 27.5 µg/L | NR |
| Lac Lindsay Coaticook County | 26.2 µg/L | NR |
| Lac Aux Canards Bellechasse County | 22.3 µg/L | NR |
| Lac Pelletier Abitibi-Témiscamingue County | 22.3 µg/L | NR |
| Lac Waterloo La Haute-Yamaska County | 21.1 µg/L | NR |
| Lac Bill Maskinongé County | 20.9 µg/L | NR |
Bloom-prone lakes in Nova Scotia
| Lake | Algae | Grade |
|---|---|---|
| Nowlans Lake Digby County | 58 µg/L | NR |
Bloom-prone lakes in British Columbia
| Lake | Algae | Grade |
|---|---|---|
| Quamichan Lake Cowichan County | 46.7 µg/L | NR |
| Michael Lake Cowichan County | 45.2 µg/L | NR |
| Nulki Lake Nechako River County | 43.8 µg/L | NR |
| Swan Lake Victoria County | 25.1 µg/L | NR |
| Quennell Lake Cowichan County | 23.3 µg/L | NR |
| Beaver Lake Victoria County | 22 µg/L | NR |
Bloom-prone lakes in Newfoundland and Labrador
No lakes with chlorophyll-a above 20 µg/L in our current dataset.
All algae-risk lakes in Newfoundland and Labrador →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.
More on algae and green water
Algae Blooms Explained: When Green Water Is Dangerous
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Algae Season 2026: The States With the Most Advisories
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Why Lakes Turn Green: Phosphorus and Nutrient Pollution
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Trophic State Explained: Blue Lakes vs Pea-Green Lakes
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