Skip to content

Blue-Green Algae in New Mexico Lakes

New Mexico Environment Department, Surface Water Quality Bureau publishes current blue-green algae advisories for New Mexico waterbodies, linked below. Enter your ZIP below to see which county you are in and what that means here, or read on for what New Mexico monitors, what concentration it takes to get a waterbody posted, and where today's status is published.

New Mexico's lowest published action level for microcystins is >0.1 micrograms per litre, which the state calls its hab watch
Recreational limit EPA records
>0.1 ug/L
Advisory levels it names
3
Link checked
2026-09-03
Today's status
Agency page below

Which New Mexico county are you in?

New Mexico advisory listings are indexed by county

This returns the agency, the toxin level it acts at and the page where it posts today’s advisories.

New Mexico publishes the lowest HAB Watch trigger in EPA’s entire compilation, at above 0.1 micrograms per litre of microcystins, which is roughly eightyfold below EPA’s recommended recreational criterion, so a New Mexico Watch is an early signal rather than a threshold exceedance. The state routes bloom reporting through EPA’s own bloomWatch app rather than running its own form.

State programs, toxin thresholds, and where each state posts today’s advisories. Blue-green algae advisories are issued and lifted by state programmes, often within days, so current status comes from the agency link on each page. Everything here is EPA’s published record of what each state monitors and what concentration it takes to post a lake. A lake with no advisory may simply not have been sampled.
Current advisories

Where New Mexico publishes today's advisories

Publishes current advisories New Mexico is one of 29 states that publish current per waterbody advisory status you can open right now, linked below.

A clear blue forest lake cordoned off with danger tape and a sign reading Lake Closed due to toxic algae
Anderson Lake State Park, Washington, taped shut for a toxic bloom on a cloudless day, with water that looks perfectly clear from the bank. What a lake looks like, and what it looked like last week, are not the answer; the posted status is. “Anderson Lake State Park scary” by ECTran71, CC BY-SA 4.0
Advertisement
What gets a lake posted here

The number New Mexico acts on

New Mexico’s lowest published action level for microcystins is >0.1 micrograms per litre, which the state calls its hab watch.

New Mexico’s own advisory levels
  • HAB Watch
  • HAB Warning
  • HAB Danger
New Mexico’s recreational microcystins levelsmicrograms per litre, log scale
  • CriteriaEPA's 8
  • HAB Watch>0.1
  • HAB Warning>8
  • HAB Danger>2000

EPA’s State and Tribal Toxin Thresholds compilation, as it stood on 2026-09-03 after its July 13, 2026 update. EPA’s numbers and New Mexico’s decisions. A threshold is what it takes to get a waterbody posted; it is not a status and it does not describe any lake today.

EPA compiles every state's advisory numbers in one table, and New Mexico appears in it with 4 recreational entries, which the state calls HAB Watch, HAB Warning and HAB Danger. EPA's own recommendation for recreational water is 8 micrograms per litre of microcystins, and adopting it is optional, which is why the numbers vary so much between neighbouring states. 32 of the 45 states here publish one and 13 publish none at all.

“This page offers a compilation of the cyanotoxins thresholds used by state and Tribal programs to make advisory decisions for drinking water and recreational uses.”

US EPA, State and Tribal Toxin Thresholds

A threshold is not a status. It is the concentration at which the state acts, and it says nothing at all about whether any New Mexico waterbody is posted today. Here is where New Mexico sits against every other state:

What it takes to post a lake, state by stateeach state’s lowest published action level for microcystins, micrograms per litre, log scale
  1. ColoradoDetect to 8Caution Value
  2. FloridaDetectHealth Notification Alert
  3. Pennsylvaniadetect to 8Recreation Advisory Value
  4. New Mexico>0.1HAB Watch
  5. California0.8Caution Value
  6. New Jersey2Advisory Value
  7. Kansas>4 to <8Watch Level Value
  8. Montana<4Tier 1 Caution Value
  9. Nevada4-8Watch
  10. New York4 - 20Confirmed Bloom Value
  11. Rhode Island4Single Tier Recreational Value
  12. Minnesota6Single Tier Recreational Value
  13. Vermont6Single Tier Recreational Value
  14. West Virginia>6Watch Value
  15. ArkansasEPA's 8Single Tier Recreational Value
  16. IdahoEPA's 8Single Tier Recreational Value
  17. IllinoisEPA's 8Single Tier Recreational Value
  18. Indiana8Advisory Value
  19. IowaEPA's 8Advisory Value
  20. Massachusetts8Single Tier Recreational Value
  21. NebraskaEPA's 8Health Alert
  22. North DakotaEPA's 8Criteria
  23. Ohio8Single Tier Recreational Value
  24. OregonEPA's 8Single Tier Recreational Value
  25. South CarolinaEPA's 8Criteria
  26. South DakotaEPA's 8Criteria
  27. Utah>8Warning Advisory Value
  28. VirginiaEPA's 8Single Tier Recreational Value
  29. WashingtonEPA's 8Warning (Advisory) Value (Guidance)
  30. WisconsinEPA's 8Single Tier Recreational Value
  31. WyomingEPA's 8Toxin Advisory Value
  32. Maryland10Single Tier Recreational Value

13 states that post on assessment rather than a published threshold

In these states the decision to post a waterbody rests on visual assessment, cell counts or professional judgement rather than on a published concentration, so there is no number to line up beside the others.

Every value is EPA’s, from its State and Tribal Toxin Thresholds compilation (146 rows, updated July 13, 2026), read on 2026-09-03. Where a state publishes several levels this shows the lowest one it acts on, skipping the bands that describe a waterbody with nothing posted and the separate, far lower values Indiana and Oregon publish for dogs. States are ordered by that number and the order is not a ranking: a low threshold means the state posts sooner, not that its lakes are worse or better than anyone else’s.

At the water

What to look for on a New Mexico shoreline

What it looks like, in the agencies’ words

  • CDC“Harmful algal blooms can look like foam, scum, mats, or paint on the surface of the water. They can also grow underneath the water, making some harmful algal blooms hard to see.”
  • EPA“Microcystis is the most common bloom-forming genus. Its blooms resemble a greenish, thick, paint-like (sometimes granular) material that accumulates along shores. Scums that dry on the shores of lakes may contain high concentrations of microcystin for several months, allowing toxins to dissolve in the water even when the cells are no longer alive or after a recently collapsed bloom.”
  • CDC“Stay out of discolored, scummy, or smelly water and keep pets away.” “If you or your animal go in water with an algal bloom, rinse off with tap water right after.”

Verbatim from CDC and EPA. Both are US Government works.

Nothing on that list distinguishes a toxic bloom from a harmless one, because nothing visible does. Toxin production turns on and off within the same bloom, so the same lake can be dangerous on Tuesday and not on Thursday with no change you could photograph. What the list is genuinely for is telling a bloom from ordinary green algae or pollen, which is a decision you can make from the bank, and after that the rule is the one every state programme in the country prints in some form: when in doubt, stay out.

“Once these toxins are released, they can cause numerous health effects ranging from minimal (i.e., diarrhea, headaches, and skin irritation) to life threatening (i.e., death).”

US EPA, Learn about Harmful Algae, Cyanobacteria and Cyanotoxins
A wooded stream completely covered in bright green cyanobacteria scum near Anderson Lake State Park, Washington
A cyanobacteria bloom carpeting a small stream near Anderson Lake State Park in Washington. Blooms are not only a big open water event: a shaded creek, a pond, a marina corner or a stock tank can carry one, and the still shallow places are where the cells pile up thickest. “Algal bloom at Anderson Lake State Park” by ECTran71, CC BY-SA 4.0

“If you or your animal go in water with an algal bloom, rinse off with tap water right after.”

US CDC, Harmful Algal Blooms and Your Health
The animal beside you

Dogs in New Mexico water

A white German Shepherd swimming through a dense bright green algal bloom on a pond
A dog swimming through a bloom on a North Carolina pond. Three exposure routes in one photograph: it is in the densest water, it will swallow some, and it will lick the rest off its coat on the bank. “2008-08-22 White German Shepherd swimming in algae” by Ildar Sagdejev (Specious), CC BY-SA 4.0

“Contact a veterinarian immediately if your pets or livestock seem sick after going in or near water. Animals can get very sick or even die within hours of coming into contact with harmful algae or cyanobacteria.”

US CDC, Harmful Algal Blooms and Your Health

New Mexico does not publish separate cyanotoxin values for dogs. Only two states in EPA's compilation do, Indiana and Oregon, so anywhere else the published number is a human number applied to an animal that weighs a tenth as much and drinks the water on purpose. That is a gap in the numbers rather than an all clear. If an animal is unwell after being in or near water, CDC's instruction is a veterinarian, immediately, and there is no waiting to see.

“If you think you have symptoms caused by a harmful algal bloom, contact a healthcare provider or the Poison Control hotline at 1-800-222-1222.”

US CDC, Harmful Algal Blooms and Your Health
Three water programs

Three different water programs in New Mexico

A clean result in one of these says nothing whatever about the other two. EPA separates the organisms and federal law separates the agencies:

“Several different types of algae can produce toxic HABs. The most common algae associated with marine toxic HABs include the dinoflagellates (e.g., Florida red tide Karenia brevis) and diatoms (Pseudo-nitzschia) while those most associated with freshwaters are dominated by cyanobacteria (e.g., Microcystis).”

US EPA, Learn about Harmful Algae, Cyanobacteria and Cyanotoxins
Common questions

New Mexico blue-green algae FAQ

Keep going

The rest of New Mexico's water picture

Blue-green algae in nearby states

Every state program

Advertisement

Threshold values are EPA's, from its State and Tribal Toxin Thresholds compilation (146 rows, last updated July 13, 2026), read on 2026-09-03; a US Government work in the public domain. The New Mexico programme link above was loaded in a browser on 2026-09-03. ZIP to county resolution uses the Census Bureau's ZCTA relationship file. In EPA's words: "State, Tribal and local governments may issue advisories for water bodies with HABs." National picture: blue-green algae programs in every state