Clean Water

Two Sisters Lake - East Bay was sampled 7 different days during the 2021 season. Parameters sampled included:
The average summer (July-Aug) secchi disk reading for Two Sisters Lake - East Bay (Oneida County, WBIC: 1588200) was 20.1 feet. The average for the Northeast Georegion was 9.9 feet. Typically the summer (July-Aug) water was reported as CLEAR and GREEN.

Chemistry data was collected on Two Sisters Lake - East Bay. The average summer Chlorophyll was 1.6 µg/l (compared to a Northeast Georegion summer average of 8.3 µg/l). The summer Total Phosphorus average was 12 µg/l. Lakes that have more than 20 µg/l and impoundments that have more than 30 µg/l of total phosphorus may experience noticable algae blooms.

The overall Trophic State Index (based on chlorophyll) for Two Sisters Lake - East Bay was 38. The TSI suggests that Two Sisters Lake - East Bay was oligotrophic. This TSI suggests deeper lakes still oligotrophic, but bottom water of some shallower lakes will become oxygen-depleted during the summer.
 

 

 

 

 

To quantify the water quality, we measure the clarity, temperature, dissolved oxygen and chemistry of the water at least 4 times during the summer months. The clarity is measured with a Secchi disk, a weighted disk with a painted black and white pattern. We lower the disk in the water until the pattern cannot be seen and then record the depth. The higher the number, the clearer the water.

 

Historically TSL has had average readings between 16 and 23 feet. In 2017 our average July and August reading was 16 feet and it has been getting deeper and clearer, since then. The 2020 average is 21 feet. Temperature and dissolve oxygen readings are normal. Chemistry measurements include total phosphorous and chlorophyll. Chlorophyll is the quantity of algae type organisms.

 

Our lake is clear and has very little algae growth. The 2020 reading is lower than last year and still in the average of the past 3 decades of data. Total phosphorous is a measure of the phosphorous which the algae need to grow. Our phosphorous reading is on a slight increase in the last 3 years but is well within historical values. The DNR rates lakes on the Trophic State Index (TSI). This index is derived from a formula that uses the clarity, phosphorous and chlorophyll values.

 

Our lake is on the upper edge of the ogliotrophic range which is excellent for a deep lake like ours.