Category Archives: Technical Lake Stuff

November 2021 Water Level Chart Archived

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November 2021

I have archived the November 2021 Water Level Chart (at left). The lake level in November was like a roller coaster ride. Our general plan for a dam operations in November is to get the lake level down a foot or so below the HWM in preparation for the lake freezing over sometime in December. A large rain event on the last day of October however brought the lake up to +0.25 ABOVE the high water mark, the highest the lake has been all year! On the first day of November we pulled one of the three remaining stop logs and opened the gate 1.05 feet to drain off some water which resulted in the lake level dropping 1.18 feet over over the next 12 days. Over the rest of the month we had numerous rain storms including one of 1.22 inches on the 12th and a 1.10 inch storm on the 22nd. This rainfall kept the lake level up higher than we would have liked. We ended the month with the lake level down 1.13 feet. Continue reading

October 2021 Water Level Chart Archived

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October 2021

I have archived the October 2021 Water Level Chart (at left). October was looking to be a very dry month with rainfall well below normal until the next to the last day of the month when a significant wind and rain storm blew through the area. I recorded 2.68 inches of rain by the time the weather cleared on the 31st, bringing our monthly total to 4.34 inches, just shy of the average for October of 4.45 inches. There was a major 3 day northeaster back on the 25th of the month that was forecast to drop 3-5 inches of rain here, but it turned out to be mostly a southern Maine rain event; here we received less than an inch of rain. I thought we’d end the month with the lake level down around 1 foot below the top of the dam, but instead, by the end of the day on the 31st the there was water running OVER the top of the dam, with the lake level the highest it’s been all year. This morning as I’m writing this, the lake level is 0.25 above the High Water Mark, and still rising. Continue reading

Exploring Lake Phenomena: Langmuir Circulation

From time to time I like to highlight different lake phenomena, and today’s high winds and waves are a great opportunity to discuss Langmuir Circulation. The waves today are really stirring up the water, it’s brown and quite turbid and there are long lines of white froth on the water aligned with the wind direction. I’m sure you’ve seen this phenomena before. You can see those lines of froth in the webcam picture at left. Sitting here in my upstairs home office and looking out the window down at the lake, those lines of white froth are very evident. Continue reading

September 2021 Water Level Chart Archived

9 Clary-Lake-Water-Level-September-2021I have archived the September 2021 Water Level Chart (at left). September was on track for being an average, ho-hum kind of month with more or less normal rainfall (for a change!) and a stable unchanging water level until the 27th when we received a whopping 4.5 inches of rain in one storm. This sounds like a lot, and it was a lot, but it only brought the lake up 0.89 feet, from -1.02 feet below the HWM to just -0.13 feet below it. While this sounds like a lot, it’s actually a runoff multiplier of only 2.4X and considering how much rain we’ve had this summer, I expected the lake to have come up a lot more. By all rights we should have had water pouring over the full width of the dam but in fact we just had a wee bit dribbling over the top in a few spots. I won’t say I was disappointed, but I was surprised! The old rule of thumb is that an inch of rain should bring the lake up 4″ (a 4X multiplier) and if that rule had held true, the lake would have risen 18 inches instead of only 10 inches. For that matter, we’ve actually seen runoff multipliers considerably larger than 4X in the past. Continue reading

September 2021 Water Quality Update

Total Phosphorus Chart

Total Phosphorus Chart

The Total Phosphorus test results from our 8/6/2021 core water sample came back the other day at 0.035 mg/liter, the highest TP value we’ve ever recorded. This is ominous. The next highest value we recorded was 0.034 mg/liter in July 2007 (see chart at left). I don’t remember the particular circumstances surrounding that reading, but there was another high TP reading of 0.032 mg/l more recently, in July 2015 that I do remember. It coincided with a secchi disk reading of only 1.95 meters indicating an algae bloom was in progress (secchi disk readings of 2 meters and below indicate a bloom in progress). You can see this 1.95 meter data point on the chart showing Clary transparency below. In this particular case, extreme low water conditions were a major contributing factor to poor water quality!! I expected a high TP value this time because of the 9″ of rain received in July. Rain means runoff and runoff means soil erosion and sedimentation which is the primary source of Phosphorus in lakes, but still, I was surprised to see such a high number. High phosphorus levels are not good for water quality! We really need to update our Watershed Survey!

Despite the high phosphorus level, we haven’t seen a significant algae bloom yet this summer and we may not, though I did notice a few wisps of dead cyanobacteria along the shoreline back in August, and water transparency is currently holding up nicely: at our last the water monitoring session on Sunday September 5th, Kelsie French and I had secchi disk readings of 3.55 and 3.45 meters respectively which is about average, and better than expected considering the level of phosphorus in the water. Transparency could deteriorate quickly however and we’re going to keep a close eye on it; we will take our 3rd and final water sample for Phosphorus testing during our next water quality monitoring session in a couple of weeks. Continue reading

August 2021 Water Level Chart Archived

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August 2021

I have archived the August 2021 Water Level Chart (at left). The 3.08 inches of rain we received in August fell slightly short of the 3.33 inch average for the month, so we’re a little further behind (-1.58 inches) for the year than we were at the end of July. We’ve received 26.17 inches of rain to date, the average for the end of August is 27.75 inches. We also anticipated a good soaking as the remnants of Hurricane Fred and Hurricane Henri passed by within a few days of each other and on August 19th and we opened the dam’s gate a foot to release some water and create some headspace for what potentially could have been a lot of storm water runoff. The storms were a disappointment however, dropping only a combined total of 0.84 inches of rain with virtually no additional runoff and we ended up closing the gate 5 days after opening it, having lowered the lake a grand total of only 3.4 inches. Now it looks like Hurricane Ida which will be passing to our south later this week may result in significant rainfall. Time will tell. Continue reading

12 August 2021: Damariscotta Lake Blooms

Damariscotta Lake has been experiencing considerable cyanobacteria growth in recent years, a troubling condition that affects many lakes in Maine. Some lakes are big enough for these types of events to impact only certain areas, though they can be lake-wide. This particular algal bloom in Damariscotta is in the Mills area. So far this summer I’ve noticed only slightly elevated levels of blue-green algae (cyanobacteria) in Clary as evidenced by faint wisps of dead algae on the water surface and slightly reduced transparency in early August. This is most likely the result of runoff from heavy rains in July. A small amount of algae growth is  expected, and is more or less normal. Clary Lake however is by no means immune to severe algae blooms, defined as a transparency of 2 meters or less and while we haven’t experienced a severe bloom since 2014 (see chart at left), it can and will under the right condition happen again. It behooves us to be vigilant and minimize soil erosion on our properties to stop the introduction of sediment and phosphorus into our lake.

Algae Bloom at Damariscotta Mills Potentially Harmful

The Midcoast Conservancy staffer Patricia Nease who is monitoring the Damariscotta Lake bloom spoke at our recent Annual Meeting about the Invasive Plant Patrol program on Damariscotta Lake and things we should consider when starting up an IPP program on Clary Lake.

July 2021 Water Level Chart Archived

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July 2021

I have archived the July 2021 Water Level Chart (at left). And just like that, the drought was over. The dry conditions that have plagued us since the beginning of the year have been effectively wiped out in one month due to the exceptional amount of rainfall we received in July. At the beginning of the month we were 6.78 inches shy of rainfall for the year. Then over the course of the month we received a total of 9 inches of rain! As of the end of the month we’re shy only 1.33 inches of the average of 24.42 inches for this date. Of course, there’s no guarantee that the drought will stay gone, but at least for now we can relax. It does appear that mid-to-late summer and fall drought conditions are the new normal. Time will tell. Continue reading

10 July 2021: Hurricane Elsa Delivers Much Needed Rain [UPDATED]

July 2021 Precipitation as of 7-10-21

On its way up the New England coast yesterday, Hurricane Elsa dropped over 3″ of rain on Clary Lake. While this won’t end our drought, it will go a long ways towards replenishing ground water supplies, and it brought the lake up enough for water to flow over the top of the dam again. For the month of July we’re now at 5.35 inches, well above  the average of 3.54 inches. For the year we’re now only (only?) 4.97 inches short of normal for this date.

water-over-the-dam-7-10-2021_compressed[UPDATE]: As of this morning and for the FIRST TIME this year, the lake level is +0.08 feet ABOVE the High Water Mark having risen 7.08 inches since yesterday morning. Plenty of water flowing over the top of the dam as the picture at left shows. What a treat to have such high water this time of year!


June 2021 Water Level Chart Archived

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June 2021

I have archived the June 2021 Water Level Chart (at left). The drought deepens. We were shy 5.20 inches of rainfall at the end of May, now we’re shy 6.76 inches of rainfall at  the end of June. We received a total of only 2.15 inches of rain in June, fully 1.58 inches less than normal. This brings us to 14.1 inches for the year to date. Our drought is nowhere near as severe as they’re experiencing in the western half of our country and especially in the southwest, but that is small consolation: this deficit will have a profound impact on our environment and ground water supplies for the rest of the year, and it’s not over. It’s so dry that even when we received a significant rainfall of 0.99 inches on the 22nd of June, the lake level only came up 1/3 of an inch. Lesser rainfall amounts during the month had almost no measurable effect on the lake level. There are two reasons for this: The primary explanation is that the ground around the lake is so dry that when the lake receives rain, the rising water is quickly wicked off into the surrounding dry shoreline. The other reason is that at this lake elevation, adding more water to the lake mostly makes the lake bigger, not deeper. Continue reading