Is the lake safe?

Jefferson County, Kansas

Perry Lake algae bloom status

No current advisory

Checked against KDHE's advisory list on 24 October 2026

Is Perry Lake safe to swim in?

Kansas has no current advisory for Perry Lake. The most recent sample, on 6 July 2021 at Perry State Park Beach, was below advisory levels (microcystin 0.43 µg/L, 42,786 cyanobacteria cells/mL). Blooms are a recurring problem here: toxic algae has been reported in 4 of the 11 years from 2011 to 2021, most often in July and August.

No recent report isn't the same as safe, because most lakes are only checked occasionally. Look at the water and the signs before you swim.

Check today on the KDHE algae bloom map
Years with blooms
4 of 11
Usual months
Jul and Aug
Samples at Warning level or higher
4 of 73
Data checked
24 October 2026
See it on the Kansas map

Perry Lake algae bloom history

The Kansas Department of Health and Environment has tested Perry Lake 73 times since 2011, usually after someone reported a possible bloom. 18 samples (25%) reached at least Watch level, and 4 reached Warning level or higher.

That puts Perry Lake in the top 25% of the 144 Kansas lakes on this site for the number of years with blooms.

  1. 2011 24 samples, Warning
  2. 2012 3 samples
  3. 2013 2 samples
  4. 2014 None
  5. 2015 None
  6. 2016 None
  7. 2017 14 samples, Warning
  8. 2018 17 samples, Warning
  9. 2019 None
  10. 2020 2 samples, Watch
  11. 2021 11 samples
Warning levelWatch levelSampled, below advisory levelsNo samples

When do algae blooms happen at Perry Lake?

At Perry Lake, reports are most often logged in July and August.

About 100% of reports fall between May and September, when warm, calm, sunny weather lets blue-green algae multiply.

Blooms can appear, move with the wind and fade within hours or days, so the time of year is only a guide.

January: 0% of reports
February: 0% of reports
March: 0% of reports
April: 0% of reports
May: 0% of reports
June: 0% of reports
July: 22% of reports
August: 78% of reports
September: 0% of reports
October: 0% of reports
November: 0% of reports
December: 0% of reports
Share of reports by month. Darker bars are the peak months.

Recent Perry Lake algae reports

Recent reports came from 6 different locations around Perry Lake, including Perry State Park Beach, Perry Yacht Club Area and Perry Rock Cr. Cove Ramp. A bloom in one cove or beach doesn't mean the whole lake is affected, and conditions can differ a short distance away.

DateLocationResult
6 July 2021 Perry State Park Beach Below advisory levels · microcystin 0.43 µg/L, 42,786 cyanobacteria cells/mL
6 July 2021 Perry Yacht Club Area Below advisory levels · microcystin 1.19 µg/L
6 July 2021 Perry Rock Cr. Cove Ramp Below advisory levels · microcystin 0.94 µg/L
6 July 2021 Perry State Park Ramp Below advisory levels · microcystin 0.54 µg/L
6 July 2021 Perry Rock Creek Ramp Below advisory levels · microcystin 1.36 µg/L
6 July 2021 Perry Old Town Park Ramp Below advisory levels · microcystin 0.72 µg/L, 56,178 cyanobacteria cells/mL
7 June 2021 Perry State Park Beach Below advisory levels · microcystin not detected
7 June 2021 Perry Old Town Park Ramp Below advisory levels · microcystin 0.23 µg/L, 11,139 cyanobacteria cells/mL
7 June 2021 Perry Rock Creek Ramp Below advisory levels · microcystin not detected
7 June 2021 Perry Rock Cr. Cove Ramp Below advisory levels · microcystin not detected
7 June 2021 Perry Yacht Club Area Below advisory levels · microcystin not detected
26 August 2020 Perry State Park Beach Watch level · microcystin not detected, 121,867 cyanobacteria cells/mL

What the Kansas results mean

KDHE sets each advisory from lab results or what staff see at the lake. Samples on this page are labelled with the level their results reached.

Watch
A bloom is visible, microcystin is above 4 µg/L, or there are more than 80,000 cyanobacteria cells per mL. Avoid algae and keep people and pets from swimming near it or drinking the water.
Warning
Microcystin above 8 µg/L, more than 250,000 cells per mL, or heavy surface scum. Avoid all contact with the water, including fishing and boating.
Hazard
Microcystin above 2,000 µg/L or more than 10 million cells per mL. KDHE recommends closing all or part of the lake and sometimes the shore nearby.

Is Perry Lake safe for dogs?

Dogs are at the greatest risk from toxic algae. They swallow water while swimming, eat scum on the shore and lick algae off their fur afterwards, and a small amount can kill a dog within hours. With blooms recorded in 4 different years here, take particular care at Perry Lake in July and August.

  • Keep your dog on a lead near water that looks green, scummy, foamy or discoloured, and away from algae washed up on the shore.
  • If your dog gets in, rinse it straight away with clean water and don't let it lick its coat.
  • Call a vet immediately if your dog vomits, drools, has diarrhoea, staggers, shakes or seems weak after being near the water.

Read the full guide to toxic algae and dogs: symptoms, what to do in the first minutes and how vets treat it.

Health effects of toxic algae

Blue-green algae (cyanobacteria) can produce toxins that affect the liver, nervous system and skin. Swallowing water during a bloom can cause stomach pain, vomiting and diarrhoea. Skin contact can cause rashes, and breathing spray from the water can irritate the eyes, nose and throat. Children are at higher risk because they are smaller and more likely to swallow water.

How to spot a bloom

Toxic blooms can look like pea soup, spilled paint or green streaks on the surface, and they can also be blue, brown, white or red. Scum often collects along the shore downwind. If you can't see your feet in knee-deep water, or you aren't sure, stay out.

Don't drink untreated lake water, and don't boil it to make it safe: boiling doesn't destroy algal toxins. If you feel unwell after contact with the water, contact a doctor or Poison Control on 1-800-222-1222.

Nearby lakes with algae reports

All Jefferson County lakes with algae reports

Questions about Perry Lake

Is there algae in Perry Lake right now?

Kansas has no current advisory for Perry Lake. The most recent sample, on 6 July 2021 at Perry State Park Beach, was below advisory levels (microcystin 0.43 µg/L, 42,786 cyanobacteria cells/mL). This site checks KDHE's advisory list every day, but lakes are only sampled after a bloom is reported, so for today's conditions check the KDHE algae bloom map and the signs at the shore.

When was the last algae bloom at Perry Lake?

The most recent entry in Kansas's data is from 6 July 2021 at Perry State Park Beach: a sample below advisory levels (microcystin 0.43 µg/L, 42,786 cyanobacteria cells/mL).

Has Perry Lake had toxic algae before?

Yes. Blooms are recorded in 4 of the 11 years from 2011 to 2021, most often in July and August.

Can dogs swim in Perry Lake?

Keep dogs out of the water whenever a bloom is reported or the water looks green, scummy or discoloured. Dogs are the animals most often killed by algal toxins because they swallow water and lick their fur. If your dog swims in water that might have algae, rinse it with clean water and call a vet if it vomits, drools, staggers or seems weak.

Can you eat fish caught in Perry Lake during a bloom?

If you keep fish caught during a bloom, health agencies advise removing the guts and liver and rinsing the fillets in clean water before cooking, because toxins collect most in the organs. Some agencies advise not eating fish from an active bloom at all, so follow local guidance.

About this data

This page uses official records from the Kansas Department of Health and Environment (KDHE), which updated as samples come in, with advisories reviewed through the April to October season. Reports are grouped by waterbody. The site was last rebuilt on 24 October 2026.

States only test some lakes, some of the time, so a lake without a recent report hasn't necessarily been checked. This page is independent, isn't affiliated with the State of Kansas, and isn't health advice. View the source data.