Lake Mgmt Plan Goal and Action Steps: Water Quality - TSI

Water Quality from a chemical makeup requires testing.  In prior years, Clearwater Lake has been tested once a year.  

Understanding that a point in time does not give us a full picture, Clearwater Lake Conservancy Board decided to test monthly in 2024.

This will help us to establish seasonal trends and help us to better recognize a change to our normal ranges.
The 3 primary tests Phosphorus, Chlorophyll A and Secchi (Clarity).  This result it called TSI.

The TSI, Phosphorus and Chlorophyll A are tested through water samples collected by volunteer Ron Green monthly.

Secchi is a process of measuring the clarity of the lake under established guidelines.   Clearwater lake has had several volunteers for this job over the years.   Currently Julie Guth and Ron Green are measuring the lake Clarity.
Water samples were sent to RMB Labs for analysis.  All test results are submitted to the DNR / Pollution control agencies for state tracking.

2024 Water Quality Survey Results


 MN Pollution Control Averages               < 30                         < 10                    8 - 15 feet

Clearwater Lake has better readings then MN lake averages in all categories.
Here is a link to the MPCA’s water quality dashboard for Clearwater Lake: https://webapp.pca.state.mn.us/wqd/surface-water/waterunit-details?wid=18-0038-00

May 2024

A.W. Research Lab Comments

Based on the data they have in their database, the 10-year average for total phosphorus is 14 parts per billion. Your May result was 21 parts per billion (ppb), so slightly higher than average. This is not unusual for spring especially given all the rain we’ve had, which can wash sediment/nutrients into the lake and stir things up. Your chlorophyll-a result of 3.3 ppb is well below the 10-year average of 6 ppb. Chlorophyll-a is a measure of the amount of algae/plant biomass in the water. We tend to see this rise throughout the summer as water temperatures warm and more algae starts growing.

June 2024

Picture
2024 - 06 - 26

July 2024
A.W. Research Lab Comments

Total phosphorus:
May's result was slightly higher than average; not unusual for spring, especially given all the rain we’ve had, which can wash sediment/nutrients into the lake and stir things up.
June results are in line with historical range.
 
Chlorophyll-a:
May and June results of 3.3 & 3.7 ppb are well below the 10-year average of 6 ppb.
 
Chlorophyll-a is a measure of the amount of algae/plant biomass in the water. We tend to see this rise throughout the summer as water temperatures warm and more algae starts growing.
A.W. Research Lab Comments
July results are in-line with historical range.
Total phosphorus is a measure of the phosphorus in the lake.  Phosphorus is a naturally occurring nutrient that is essential for terrestrial and aquatic plant growth. If levels are too high, this can result in algal blooms and excessive aquatic plant growth that negatively impact the aquatic community when these blooms die and decompose. The July reading was slightly lower than 10-year average.
Chlorophyll-a is a measure of the amount of algae/plant biomass in the water and July’s reading was lower than the 10-year average.
Water Clarity – Secchi Disk Readings:
July data shows a reduction of clarity but still within the historical average (Lab says they typically see a reduction in clarity during July due to increased recreational activity in lakes).