For those not familiar with water quality sampling at Lake Sawyer, twice a year, in May and August, samples are taken to measure phosphorus concentrations in the lake at depths of 1, 8 and 15 meters. Phosphorus is the best single indicator we have as to the health of the lake and potential for algae growth and eutrophication. The lower the numbers, the better. As one might expect, phosphorus concentrations are consistently lower in May, when stream flows into to the lake are high, and higher in August when the lake is lower and there is limited stream flow. Following are the results posted earlier for May. Trends are what we need to be concerned about.
Though we see some significant fluctuations, trend lines at all depths are essentially flat. The same can be said for sample results in August.
Because flows and water levels vary significantly from year to year in August, we see more significant variations - though no clear trend at this point. You might note that lake water levels were particularly low in 2015 and again this year.
Number one concern right now are plans by Pacific Coast Coal to restart the John Henry mine. Will keep you posted.