And so we start another year! I have archived the January 2025 water level chart (above, and at left). The drought conditions we experienced last Fall have returned. We ended 2024 with a big wet month of December but since then precipitation in any form has been sorely lacking. There is virtually no snow pack which will be felt this spring when we’re trying to fill up the lake again. Normal precipitation in January at 3.19 inches is rather low to begin with, with only February having a lower average monthly precipitation (2.61 inches). As it is, we’re ending January with only 1.81 inches of precipitation, only 55% of normal. As of January 21st, the coastal section of Maine was in Moderate Drought. The 6″ of precipitation we received in December has done little to alleviate generally dry conditions and I suspect ground water supplies in this area are not in good shape.

The lake level came up early in the month from 1.28 inches of rain we received on January 1st, peaking at -0.79 feet but since then, with little rainfall or snow to add volume, the lake level has steadily dropped, ending the month at -1.54 feet or just a hair over 18 inches below the high water mark. It is not too soon to start thinking about Spring, and we’ll probably start raising the lake level soon by adding stop logs to the weir. The gate is currently closed.

Other than biweekly conductivity testing, we don’t conduct any water quality monitoring this time of year, though that may change in the future. Still, there is plenty of data to collect and think about! One bucket of data that we keep a close eye on are outflows from the lake because lake outflows in winter and spring appear to correlate, if loosely, with lake water quality later in the season. While we do have some control over outflows with gate and weir settings, total outflows are mostly influenced by weather and precipitation. The chart at left shows total outflows in acre-feet for the past 7 years as of February 1st, 2025. Also shown are the corresponding outflows in lake volumes, calculated by dividing outflows in acre-feet by the lake’s full volume in acre-feet (7224). As of today (2/1/2025) only 1313 acre-feet of water (0.18 lake volumes) have flowed out of the lake to date which isn’t much compared to last year on this date when 3,388 acre-feet (0.47 lake volumes) had flowed downstream. If you recall, we experienced exceptional water quality last year and high winter and spring outflows had a lot to do with it. This year we’re also well behind outflows in 2023 and 2019, but we’re somewhat ahead of outflows in 2020, 2021, and 2022. Remember, this chart is just a snapshot in time and it isn’t possible to predict from this data alone what our water quality will be this coming summer.

Speaking of conductivity, the chart at left shows lake water conductivity for 2023, 2024, and the start of 2025 along with average conductivity and precipitation (green) for the current year. Conductivity is measured in microsiemens per cubic centimeter (μS/cm), a standard measure for electrical conductivity of water. Conductivity is a proxy for lake productivity because it reflects the concentration of dissolved ions in the water which increases with higher concentrations of dissolved salts, minerals (such as Phosphorus), and other pollutants. Conductivity of distilled water is typically quite low, ranging from 0.5 to 3 μS/cm depending on impurities. Rainwater and snow also tend to have a lower conductivity than lake water though runoff can pick up sediment and impurities that will increase conductivity. As you can see, lake water conductivity is very high this winter compared to previous years, in fact at 71.1 μS/cm, it’s the highest value we’ve ever recorded since starting collecting conductivity data at the start of 2023. This is likely due to a lack of precipitation so far this winter which would serve to dilute the lake water. Again, there’s little point in speculating at this point what this data means for water quality this coming summer. I would point out however that conductivity last year when our water quality was so good was generally lower than during the previous year when we had a significant late fall algal bloom. Another interesting aspect of the chart is the spike in conductivity in March 2023 corresponding with spring runoff which likely included sediment and dissolved road salt. There was a corresponding drop in conductivity last year around the same time due to large inflows resulting from over 10 inches of rain received in March 2024.

Now that February is here I suppose it’s time to start thinking about our Annual Ice Out contest!