The volunteer water monitors, mentioned in the previous post, have one more responsibility on their monthly trips to the middle of Carlin Lake. Most of you have probably seen the black and white disk on a rope--called a secchi disk--which the volunteer drops into the water. He watches carefully for the moment when the black and white divisions become indistinguishable, and records that depth.
This of course indicates water clarity, or how deep into the water it is possible to distinguish contrast. Last summer the average secchi disk depth was 22 feet. PIcture the height of two ten-foot high diving boards. Or, if you haven't been at a swimming pool lately, try to picture three and a half men six-feet tall standing on each others' heads. (Personally, I'm finding that a little difficult to picture, too.)
This graph shows what we all would hope to be true---that the water quality in Carlin Lake has not discernibly decreased since 1993, when records were first kept. Note that in that first year, average secchi disk depth was 22 feet, just as it was last summer in 2010. (Click to enlarge the graph.)
So, aren't we fortunate! And aren't we equally determined to do all we can to keep Carlin water this clear? Maintaining deep buffer zones and vegetation along shorelines slows run-off into the lake, inhibiting algae and plant growth.