Water clarity this spring, 2021, in Pine Lake
This spring the water clarity in Pine Lake was very poor. When a secchi reading (how far below the surface you can see a standard white disk) was done in May, the reading was 8 feet. This was not typical at all. Usually, in the spring the reading is 20 feet or more. The secchi disk reading improved in coming weeks but still remained below normal. It June and July, the water tests that have been done in the past were done. The traditional tests that have been done since 2008 are Total Phosphorus, Chlorophyll-a, and Secchi reading and are analyzed and reported by RMB Labs (RMB Lakes Database - RMBEL). The Pine-Cedar Lakes Association has done these tests for the recommended 10 years to get a good base. After the 10 year base, the plan is to do them every other year. This year, 2021. was not planned to be a year to take the tests. But because of the abnormal clarity, tests were taken for two months. The following are the results:
Mean- since 2008 TP-- 6/21/2021 TP-- 7/25/2021
Total Phosphorus 14.3 ug/l 15.6 ug/l 10.2 ug/l
Chlorophyll-a 2.8 ug/l 7 ug/l 3 ug/l
Secchi reading 16.6 feet 13 feet N/A
The Secchi reading for 7/25/21 did not make the RMB report. A reading taken later was 14 feet. The Secchi reading has usually been in the 20 foot range in the spring and the mid teen feet level in the late summer. As can be seen by the data, the lake has basically returned to normal with the July reading. The June Chlorophyll-a of 7 ug/l was the highest recorded since the test started in 2008. This test reflects algae in the water.
It is not know what happened in the lake this spring to cause the clarity to change so dramatically. There was probably a bloom of some sort. The weather and water levels were not normal in the spring of 2021. The good news, it has cleared.
It is, however, good to remember that all activity in and around the lake may affect the lake water eventually.
