THE POTATO LAKE WATER QUALITY REPORT
By Rich Rothermel
When the PLA developed a Strategic Lake Management Plan in 2006, Water Quality was one of the top three strategic objectives, reaffirming our commitment to protecting our lake. The original management practices are still vital for the health of our lake. Water quality monitoring is a key way to measure the lakes health.
Since 1997 PLA has participated in a water quality program sponsored by Hubbard County COLA. This program is more specific than just water clarity, by measuring certain harmful nutrients in the water. Once each month (five summer months) on an assigned date a sample of water is collected and sent to RMB Environmental Laboratory for analysis of the amount of phosphorus and chlorophyll- A. Phosphorus is a nutrient needed for plant growth (algae). Phosphorus can enter a lake through runoff from fertilizer or seepage from faulty septic systems. Chorophyll-A is the pigment that makes plants and algae green so it serves as a measure of algal concentration.
The RMB lab analysis when combined with a Secchi disc clarity measurement provides a trophic state index (TSI) which is one means available to examine the level of biological productivity in a lake. Our TSI has consistently been in the mesotrophic range which is typical of lakes in our region.
Lab analysis of our lake data currently shows the following general results:
Total Phosphorus:
2021 mean – 12.6 ug/L
2012-2021 mean – 13.1 ug/L
1997-2021 mean – 13.9 ug/L
Chorophyll-A:
2021 mean – 3.6 ug/L
2012-2021 mean – 4.0 ug/L
1997-2021 mean – 5.0 ug/L
Secchi Disc:
2021 mean – 12.7 Ft
2012-2021 mean – 12.6 Ft
1997-2021 mean – 12.2 Ft
TSI:
2021 mean – 41.2
2012-2021 mean – 41.6
1997-2021 mean – 42
In addition to the monthly lab analysis, Potato Lake currently monitors five specific sites for water clarity. Volunteers for the Citizen Lake Monitoring Program (CLMP) are Chuck Diessner, Rich Rothermel, Len Lamberty and Mike Cohrs. Data from this program shows no significant change in water clarity.
If you wish to see more water quality data for Potato Lake, go online to the following addresses: https://www.dnr.state.mn.us/lakefind/lake.html?id=29024300
or check out http://www.rmbel.info – Lakes Program – Lakes Data Base
Potato Lake Association 