Water Quality

Monitoring Season: Memorial Day to Labor Day

DLWID is within its summertime weekly monitoring season which runs from Memorial Day through Labor Day. Updates will be posted weekly and as they come available.

STAY INFORMED: Join the Water Quality email list. Get weekly updates sent directly to your email throughout the summer months. Click here or Text WATER to 42828 to enroll.


Recreational Water Quality Standards

Parameter Description and human limit Dogs***
Anatoxin-a A neurotoxin – Less than 8 ppb 0.4 ppb
Cylindrospermopsin A liver toxin – Less than 6 ppb 0.1 ppb
Microcystin* A liver toxin – Less than 4 ppb 0.2 ppb
Saxitoxin A neurotoxin – Less than 4 ppb 0.02 ppb

*DLWID monitors for Microcystin as it is often the most common toxin.  Values are shown above if sampling is warranted based on visual observations.

***Animals are extremely sensitive to cyanotoxins. Routes of exposure are ingestion when pets and wildlife drink water from a harmful algae-filled lake or pond, lick their fur after swimming or eat dried cells that accumulate along the shoreline. If toxins are present when animals drink the water, the animals can become very ill and possibly die.

Italicized values reflect most recent data, collected in previous week.


  • What is HABs?  The Harmful Algal Bloom Surveillance (HABs) program is a water quality monitoring system for blue-green algae and algal toxins. Blue-green algae, scientifically known as cyanobacteria, are small, mostly microscopic, photosynthetic organisms. Some blue-green algae naturally produce toxins, which is why they can be a concern. In nutrient rich water they can reproduce rapidly into what are known as Harmful Algal Blooms (HABs).  This program has been developed based on Oregon Health Authority’s Harmful Algae Bloom Advisory Guidance, and in 2012 replaced the Cyano-Watch program the District initiated in 2006.
  • What does DLWID do?  As part of the program the Devils Lake Water Improvement District conducts routine monitoring of blue-green algae and algal toxins during bloom events.  Signage is posted around the watershed in a three pronged approach designed to educate, inform, or advise about the use of Devils Lake.

What do blue-green algae blooms look like? A bloom can look green, blue-green, white, or brown and can form a scum on the surface of the water. They can often be found in large concentrations near the shore.

When do blooms occur? Blooms can occur anytime of the year, but are most common between June and September when water temperatures are typically higher. As a result Devils Lake is monitored from Memorial Day to Labor Day.

What should I do if I see a bloom?

• Avoid swimming and water-skiing, where blooms are present.
• Keep pets away.
• If you or your pet have contacted the affected water, wash thoroughly with a clean source of water.
• Do not use for drinking or cooking. Toxins cannot be removed with filtration, boiling or chemical treatments.
• Activities near the water such as camping, picnicking, biking, and hiking are safe.
• Boating at slower speeds is safe provided excessive spray is not created and thus inhaled.

How do I know if a bloom is toxic? Blue-green algae blooms cannot be determined toxic just by looking at them. Testing is required.

For information about about potential toxicity, look for signage at lake access points, sign-up for our email service, and/or bookmark this webpage to see the very latest water quality updates.
It is important to note, that blooms can form rapidly and water quality can change as result. Blooms may develop between monitoring visits. Also while the District samples for one of the most common cyanotoxins, Microcystin, other toxins may exist. Therefore, always watch and stay clear of algal blooms and scummy water.
If in doubt…stay out!

How dangerous are these algal toxins? Skin contact can cause rashes or irritation. Significant Ingestion or inhalation can lead to diarrhea, nausea, cramps, fainting, numbness, dizziness, tingling,and in rare cases, paralysis and death. Children and pets are most at risk.

What about fishing? Eating fish caught during a bloom can pose an unknown health risk. Thoroughly cleaning a fish of its guts, skin and head before cooking reduces the risk. For additional information about fish consumption contact the Oregon Health Authority.

  • The Devils Lake Water Improvement District conducts weekly E. coli tests of the freshwater beaches and major tributaries of Devils Lake in the summer months. The data are for your information only, and do not indicate a closure or an actual advisory, but are posted here to serve as a guide to water quality in and around Devils Lake and the D River.
  • The current value for each sample site is listed and color coded Red, Yellow or Green. These colors are associated with health risks based on state and federal guidelines for freshwater swimming waters.
  • E. coli themselves with rare exceptions are generally harmless, but they are correlated with fecal inputs to the lake which may contain pathogenic agents. E. coli then are used as an indicator organism for such fecal inputs.
  • Sources of E. coli include humans, birds, cats, dogs, horses, and other warm blooded animals in the watershed.
    Please Do Not Feed Seagulls, Ducks or other birds.
    Likewise pets also contribute to the degradation of water quality and pet owners need to mindfully clean up pet waste. Incremental effects do add up and thus protecting Devils Lake is the responsibility of everyone in the watershed.
  • Please note that water quality can change quickly and is highly impacted by runoff from urban environments. After a storm event it is generally best to wait 48 hours before swimming near where storm drains meet receiving waters.
  • For information from the World Health Organization about Recreational Water Use, click here.
  • Click here for information about Oregon’s Ocean Beaches’ Monitoring Program.