Lake Tye Depth & Water Quality Testing

Lake Tye is a popular recreational lake located at the western edge of Monroe.  Throughout the year residents and visitors spend time at the lake swimming, paddling, fishing, and enjoying the surrounding park area.  

As required by the Washington State Department of Ecology, the City collects routine lake water samples to measure lake temperature, dissolved oxygen levels, and the current level of fecal coliform present in the water.  

For questions or concerns regarding the water quality at Lake Tye, please visit Monroe Listens or 360-794-7400 during normal business hours.

Lake Tye Swimmers

Lake Depth

The Lake Tye water level fluctuates by approximately 3 feet seasonally. A bathymetric survey was done on the south half of the lake in 2012. At that time, the lake at its deepest point was approximately 29 feet. Certified city staff consistently monitors water levels to ensure the proper functioning and environmental health of the lake.  The lake is approximately 40 acres in size. If you have any further questions or concerns, please visit Monroe Listens or call 360-794-7400 during normal business hours.

Water Quality Results

Fecal coliform bacteria are typically present in lake waters. They are used as a key indicator to determine the health risk of water contaminated with fecal material and if there is a public health concern. Although fecal coliform bacteria are ever present in lakes and streams, elevated levels above 1000 CFU/100ml, typically indicates that other disease-causing bacteria may be present. Should levels in Lake Tye exceed 1000CFU/100ml, the City will notify the public.

MONTH/YR. JAN
2023
 FEB
2023
 MAR
2023
 APR
2023
 MAY
2023
 JUNE
2023
 JULY
2023
 AUG
2023
 SEPT
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 DEC
2022

FECAL COLIFORM BACTERIA - CFU/100ML

   7   4    1    5    2    8   22   11    4   16    9     5
FIVE YEAR AVG.  FECAL COLIFORM BACTERIA - CFU/100ML 
59.2

Lake Temperature is measured to predict the general health of the biological activity within the lake. If temperatures are exceedingly high, or low, fish, insects, zooplankton, phytoplankton and other aquatic species may be affected. As is to be expected, lake temperatures typically increase as the weather warms in the summer, and decrease as the weather cools in the winter.

MONTH/YR. JAN 
2023
 FEB 
2023
 MAR
2023
 APR
2023
 MAY
2023
 JUNE
2023
 JULY
2023
 AUG.
2023
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 DEC.
2022

TEMPERATURE - F

 44.2 44.6 45.5 49.8 63.32 69.8 75.38 75.74  69.44 61.7  54.3   42

Dissolved Oxygen is an important measure of water quality for aquatic life. When dissolved oxygen levels become low (less than 5 mg/l) aquatic life may suffer. Factors that may affect the level of dissolved oxygen in the lake include atmospheric pressure, water temperature, aquatic plant life cycle, ground water levels, and pollution in the water. For these reasons, it is normal for dissolved oxygen to fluctuate seasonally.

MONTH/YR. JAN
2023
 FEB
2023
 MAR
2023
 APR
2023
 MAY
2023
 JUNE 
2023
 JULY
2023
 AUG
2023
 SEPT
2023
 OCT 
2023
 NOV
2023
 DEC
2022
DISSOLVED OXYGEN - MG/L 10.5 10.7 12.9 11.3 13.1 11.1  9.6  9.1  9.0   7.3   9.0   9.9

Caution Blue-Green Algae

Blue-Green Algae is a potentially toxic type of bacteria (cyanobacteria) which is found in many of Snohomish County's lakes. Blue-green "blooms" are most commonly present when water temperatures are warmest in the summer months.

Protecting humans and pets by eliminating contact with and ingestion of blue-green tainted water is advisable.  If you become aware of a possible bloom, please report it to City staff so that an assessment and testing of the algae can be completed as necessary.