Category Archives: Technical Lake Stuff

46th Annual Maine Lakes Conference Coming Up June 25th

The Maine Lakes Society (formerly the Congress of Lake Associations or COLA) is holding their Annual Maine Lakes Conference on the 25th of this month. The itinerary, as usual, looks excellent. The Clary Lake Association is a long-time member of the Maine Lakes Society. For years the annual COLA conference was attended by Association Member Ed Grant. I’ve made a point of going in recent years and I always learn something new. I’ll be going to this one. The cost is $35 which includes lunch.

Here’s the email notice I received about this event:

We invite you to join us at the 46th Annual Maine Lakes Conference on Saturday, June 25th, at the Unity College Center for the Performing Arts!


	Keynote Speaker Holly Ewing of Bates College

This year we look to the future of Maine lakes monitoring and protection, and the myriad ways citizens can get involved in lake protection. Our Keynote Speaker, Holly Ewing of Bates College, will introduce us to the latest research on Gloeotrichia echinulata blooms and GLEON, the Global Lake Ecological Observatory Network, which is helping scientists and citizens alike better understand and communicate the way lakes are responding to our changing climate. Afternoon workshops on citizen science, lake and fisheries restoration, the latest on LakeSmart, new partnerships with Maine Audubon’s Stream Smart and LoonSmart programs, translating science in your outreach products, and hands on workshops offer diverse learning experiences at a great new venue in Unity, Maine.

REGISTER TODAY!

Additional Workshops include:

Cyanotoxins and Maine’s developing Public Alert System for Harmful Algal Blooms
What’s that stuff in the water? The appearance of metaphyton and other algae in our lakes and ponds
Long term, statewide collaborative lake monitoring efforts
Special guest Friends of Lake Winnecook
The latest “Get Smart” tips from LakeSmart and Stream Smart
Hands on instruction with lake monitoring technology
Our new partnership with Maine Audubon’s LoonSmart Program
Creative tools for translating water quality data into meaningful communications
Lake and fisheries restoration efforts
Nature Journaling ~ Fish Identification ~ Art Exhibit
Lunchtime breakouts: Council of Lake Associations Annual Roundtable, Camp Care, and Invasive Plant Monitoring FAQ’s

The annual conference will be at the fabulous Unity College Center for the Performing Arts nearLake Winnecook in Unity, Maine. Keep an eye on our Facebook page and website for more information on presentations and speakers. We are also still welcoming conference sponsors!

We hope to see you there!

*Cheryl Daigle*	&	*Maggie Shannon*
Executive Director		Program Director, LakeSmart & Policy

Maine Lakes Society
P O Box 447

Belgrade Lakes, Maine 04918

www.mainelakessociety.org

207-495-2301

04 June 2016: Early Summer Clary Lake Water Quality Update

Clary Lake Total Phosphorus

And it’s not good news. We’ve received the results back on our first Total Phosphorus (TP) sample for 2016, taken last month on May 20th. At 22 μg/L (micrograms per liter), TP is up at levels typically not seen until mid to late summer. The chart at left has been updated to include this latest data point, you can see where it plots up: it’s the first (only) dot in 2016, furthest to the right. We usually take 3 [the_tooltip text=”core” tooltip=”a sample of the whole water column from the surface down to 7 meters” url=”” background=”” color=””] samples of lake water each season for Phosphorus testing, and send them off to the State Lab for analysis. In the early spring, TP values on the order of 14 to 18 μg/L are more “normal” (for some value of the term “normal”) though in recent years they have been trending higher. Last spring on April 30th TP was 14 μg/L and 17 μg/L on April 25th the year before that. TP values above 18 μg/L typically mean an algae bloom is on the way. This does not bode well for water quality this coming summer.

Phosphorus is the primary nutrient responsible for algae growth in lakes. It comes from various sources including runoff containing eroded soil and sediments. Under conditions of low dissolved oxygen it can be released from bottom sediments in the lake. Wave action on exposed bottom sediments can also result in Phosphorus being released into the lake. Low water conditions resulting in exposed bottom sediments and reduced lake volume certainly contribute to higher Phosphorus concentrations.

David Hodsdon, Jack Holland and I went out yesterday morning for our regular biweekly water quality monitoring session. The transparency of the lake water has already dropped from 4.1 meters to 3.65 meters since May 20th . Data collected back through 2012 is available on the Clary Lake Water Quality Data page. Data back to 1975 is available upon request.

May 2016 Water Level Chart Archived

May 2016

I’ve archived the May 2016 Water Level Chart (at left). The most notable features of the May chart are the lack of rainfall for the month and the inexorable fall of the lake level despite the gate having been mostly closed on the afternoon of Thursday, May 19th. In fact, after the gate closure, there was almost no noticeable reduction in the rate at which the lake lost water during the month (0.025′ before vs. 0.019′ after). The lake level started out at -47.88″ below the top of the dam and fell an average of only 0.02′ per day (less than 1/4″) ending up at -55.68″ below the top of the dam, for a total loss of -7.8″. The lake fell 28 out of 31 days during the month while remaining unchanged on only 3 days. Not once during the month did the lake level rise.

I wrote about the gate closure back on May 21st (see: “Clary Lake Dam’s Gate Almost But Not Quite Closed“). I presume the dam operator left the gate partly open to maintain minimum outlet flows as required by the Clary Lake water level order, but clearly the gate was left open too much: in my estimation, net outflows (including evaporation) have exceeded inflows by as much as 5 CFS (Cubic Feet per Second). Any way you look at it, the simple fact that the lake level continues to fall indicates the gate opening is too great: minimum flows are never supposed to exceed inflows. For more information about minimum flows and where they come from see Minimum Flows Explained.

Average rainfall for May is around 3.7″ but we received only 1.79″ of rain for the entire month, considerably less than 1/2 the normal amount. Less precipitation means less runoff obviously; it is likely that if we’d been receiving the normal amount of rain for the month that the lake level would have more or less stabilized once the gate was lowered.

21 May 2016: Clary Lake Water Quality Monitoring Resumes for 2016

On Friday May 20th David Hodsdon and I (Jack Holland was not able to join us) were finally able to resume Clary Lake Water quality monitoring for 2016 albeit a month later than we had planned, but still within the allowable time frame. Better late than never as the saying goes. We had originally planned on starting a month ago, but our YSI Pro 20 digital dissolved oxygen meter which the Association purchased through donations a few years ago failed to pass routine calibration which is performed each spring by Maine VLMP technicians. They first thought the problem was a bad probe but swapping it out for a known-good probe didn’t solve the problem. YSI Technical Support suggested it might be water in the cable connector housing so they let the unit sit around disassembled for a few days to dry out. After that it started working intermittently. They ran some more tests on it over the next week finally certified it for use with the instructions to “keep an eye on it.” We got it back midweek last week.

This first time out, the DO meter worked flawlessly (and we hope it continues). With a secchi disk reading of 4.1 meters (13.25′) the water clarity is excellent, and about normal for this time of year. But be warned: it’s early in the season yet, and the water quality can and will deteriorate. The lake has yet to “stratify” meaning that it is pretty homogenous (well mixed) and there is no thermocline yet: the temperature from the surface to the bottom only varied 2.5° Celsius. This means that if you were to go swimming now you’d think the whole lake was cold, not just 6′ down like during the summer. Likewise, the dissolved oxygen reading only varied 2.6 mg/l from surface down to 7 meters. Continue reading →

21 May 2016: Clary Lake Dam’s Gate Almost But Not Quite Closed

Late last Thursday afternoon for reasons known only to himself, the Clary Lake dam owner closed the dam’s gate to within about 7″ of completely shut. As you can see from the picture at left, there’s still quite a bit of water flowing out of the lake but the mill pond behind the dam has considerably more water in it than when the gate was wide open. However, while the water may be backing up behind the dam, the lake level is still falling about 1/4″ per day. Remember, water only flows down hill and there is a mile and a half of meandering channel down which the water has to flow to get from the lake to the dam. With the gate wide open and the lake this low, I suspect the water level right at the dam itself has been as much as 2 feet lower than out on the lake, perhaps even more. I’ve actually measured a 3″ difference when gate was wide open and the lake was almost full. Albert Boynton whose family owned the dam in the 1920’s and who was actually born in the little red house on the dam told me once that after a morning of sawing lumber, the upper mill pond would have fallen considerably; when they returned from dinner, it would be full again.

Continue reading →

April 2016 Water Level Chart Archived

April 2016

I’ve archived the April 2016 Water Level Chart (at left). The most notable feature of the April chart is that the lake level stayed pretty stable around -34″ below the top of the dam for the first 15 days of the month (despite the dam’s gate being wide open) after which point it began to fall steadily, ending the month at -47″ below the top of the dam. All in all we received only 3.33″ of rain in April which is less than the average monthly precipitation of 3.78″. This lack of rainfall has contributed to the dry conditions we’re seeing now. Most of the rainfall occurred in the first half of the month, with 2.68″ falling by April 15th which explains the relatively stable water level during that time. Only an additional 0.65″ fell during the second half of the month.

I’ve added a new statistic to the monthly water level chart, that being the volume of Clary Lake at its current level as a percentage of full. This new data has been added to the middle “narrative” portion of the Current Water Level Charts page. The figure comes from a volume analysis I’ve been working on this past winter based on the Clary Lake Depth Chart (at left) that I prepared from data collected by DEP during their September 2012 bathymetric survey and additional [the_tooltip text=”LIDAR” tooltip=”Lidar (also written LIDAR, LiDAR or LADAR) is a surveying technology that measures distance by illuminating a target with a laser light. Lidar exists as an acronym of Light Detection And Ranging. LIDAR data is typically collected from planes.” url=”” background=”” color=””] data I obtained from the Maine Office of GIS. In theory calculating volumes from a contour map is pretty straight forward and is a task most land surveyors are familiar with, but the size of Clary Lake presented some challenges and there turned out to be a considerable learning curve to the GIS software I used to extract the information I needed for my calculations. I finally got it figured out.

Currently, at -47″ below the top of the dam, the lake is about 66% full and the area has shrunk to about 473 acres of about 62% of its size when full. Continue reading →

09 April 2016 BDN: What an early spring means for Maine’s lakes

Clary Ice Out

You’ll recall that the ice went out on Clary Lake on March 13th this year, the earliest since we started keeping records in 2001. Well there’s a great article in today’s Bangor Daily News about the potential impact of an early spring on lake water quality. Basically, warmer than usual weather coupled with an early ice-out result in water temperatures rising higher, sooner, and lake stratification taking place sooner as a result. Stratification is the process whereby the water in the lake separates into a warm, generally oxygen-rich upper layer and a colder, generally oxygen-deprived lower layer. You’ve all experienced lake water stratification when you jumped into nice warm water only to discover that 4′-5′ down the water is a whole lot colder. One impact of oxygen deficiency in a lake is the release phosphorus from bottom sediments which leads to algae growth. The article is short and informative and worth a read:

BDN: What an early spring means for Maine’s lakes

The excessively low water conditions we’ve been experiencing on Clary Lake for the last 5 years or so have also had a severe impact on water quality, compounding the effect of the normal seasonal lake water cycles, resulting in more, and more severe, algae blooms. This is in part due to severely diminished lake volume, loss of wetland habitat, and erosion and sedimentation of bottom sediments around the edges of the lake that normally would be covered by a protective 4′-5′ of water.

The CLA will be starting it’s water quality monitoring activities next week. There is water quality data for Clary Lake going back to 1975 (available by request). You can view the water quality data back to April 2012 online on our Clary Lake Water Monitoring data page.

March 2016 Water Level Chart Archived

March 2016

I’ve archived the March 2016 Water Level Chart (at left). The most notable thing about the March water level chart is that while the lake level has been generally falling since the beginning of the month, it has still been significantly higher throughout the whole month- indeed, throughout the whole winter- than in any of the last 5 years. Part of this is due to a very early ice out (March 13th) and above average rainfall for the first 3 months of the year. The dam’s gate has been wide open since January 4th. As high as it has been, it has still been generally lower than the lower-limit (2′ below normal high water mark) specified in the Clary Lake water level order.

I spoke to David Hodsdon the other day about resuming our water quality monitoring activities. He’s going to send the Association’s YSI Pro20 digital dissolved oxygen meter off to be calibrated tomorrow (a yearly VLMP requirement) and as soon as we get it back we’ll set a date to hit the lake and start collecting data again. To that end, I launched my boat this morning- the earliest I’ve ever gotten it in the water. We try to collect data every 2 weeks during the recreational boating season, typically between mid-April through October. This will be David’s 40th year as a Volunteer Lake Monitor. Way to go David!

15 March 2015: Yet Another Time Lapse Video of Ice-Out, Spring 2016

The first ice-out video I posted has been so popular I decided to make one from images captured by David Hodsdon’s ClaryCam2 webcam. Ice-out primarily occurred over 2 days starting March 10th but I decided to include a third day because it started with an incredible sunrise, and around 11:30 AM an ice floe goes by 🙂

13 March 2016: Ice Out on Clary Lake

Clary Lake Ice Out 3-13-16

David Hodsdon usually makes the official ice-out determination but I haven’t heard from him today and according to my precise calculations, today Clary Lake became completely ice-free. The northwest end of the lake from the outlet around the point at the end of Duncan Road has been ice-free for some days but the southern side which gets less direct sunlight was still mostly iced in until yesterday. Today’s high winds (see above) rapidly broke up and dispersed the remaining ice sheets. Today marks the earlier start of the open water season on Clary Lake going as far back as 2001, when our records start. The criterion for ice-out is when the lake is sufficiently free of ice that one can boat round the lake within a few feet of shore (essentially completely free of ice).

According to the Clary Lake Water Level Order, at ice-out the lake level should be at or very near the “normal historical high water mark” of the lake which has been determined by DEP survey to be at an elevation of 151.2′ which corresponds with the top of the dam. The lake level is supposed to be maintained at that elevation or as close to it as possible through the end of July to provide a stable water level to maintain fish and waterfowl breeding habitat. Unfortunately, the lake level is currently a little more than 2 feet below that elevation and falling and with no snow pack to provide spring runoff, we’re entirely dependent on spring rains to keep the lake level from falling too far, too fast. I’m not very optimistic.

I’ll post a time lapse video of this year’s ice-out shortly. I can’t wait to get my boat in the water.

February 2016 Water Level Chart Archived

2 waterlevelchart_February2016 I’ve archived the February 2016 Water Level Chart (at left). The most notable feature is that the lake level stayed in a fairly narrow range around an average of -34.5″ belog the top of the dam, for all but the last 5 days of the month when the level rose to within touching distance of where it should be this time of the year, around -24″ below the top of the dam. This was by chance and not design because the gate has remained wide open since January 4th.

Another factor contributing to a (relatively) stable lake level is that between precipitation events, the lake level dropped an average of only 0.6″ per day, considerably less than the 1″ per day we would expect. This is likely due to frozen ground and warmer than usual winter weather resulting in increased snow melt and runoff. Recall this table which I first compiled back in 2012:

Lake level in inches below top of dam	Rate of fall in inches in 24 hours
0" to 36"	1"
36" to 48"	3/4"
48" to 62"	1/2"
Below 62"	1/4" or less

We received a total of 3.26″ of precipitation in February or 0.82″ more than the average of 2.44″ for the month. Most of the precipitation was in the form of rain and/or ice. If it had all been snow we’d be in record territory but as it is, snowfall for the 2016 winter is well below average. This is likely attributable to the El Niño phenomena that is affecting everyone’s weather this year. The lack of significant snow pack does not bode well for spring runoff and lake levels this coming spring.

January 2016 Water Level Chart Archived

January 2016

I’ve archived the January 2016 Water Level Chart (at left). The most notable thing about it is that the gate was closed for the first 3 days of the month, and that the lake got up to 15″ below the top of the dam on January 13th. It has fallen steadily at about 1″ per day since then however, and ended the month about 35″ below the top of the dam. For a little more than 1/2 the month the lake level was at or higher than 2 feet below the top of the dam. It hasn’t been that high for that long since sometime in 2010. We received 2.7″ of precipitation for the month, most of it in the form of rain. Average precipitation for January is 2.6″ so we’re just wee bit ahead so far this year though still showing a precipitation deficit from last year.

We had a couple of days of decent ice skating around the 8th of January but then it snowed and rained. The falling water level combined with warming temperatures led to some pretty strange ice conditions later in the month.

You’ll also notice that the black line on the charts at 34″ that marked the approximate bottom of the hole in the dam has been removed. I got rid of it because I no longer believe that figure is accurate.

28 January 2016: Strange Clary Lake Ice Conditions

Ice conditions on Clary Lake this winter are pretty strange and I can’t say as I’ve ever seen anything quite like what is happening this year. Currently there is about 7″ of ice on the lake but due to a combination the falling lake level (it’s fallen about 15″ since freezing up), recent snow, and January thaw temperatures, much of the lake is covered by 2″ to 4″ of water on top of the ice. This results in a slushy mixture which adds considerable weight to the ice, pushing it down and forcing water up through holes and cracks in the ice. I probably wouldn’t have been out on the lake in the first place except I saw my neighbor and a friend out setting ice fishing traps using his snow mobile to haul their gear. I decided to walk out and say hello, which is when I encountered the bubbling “spring” in this video:

What you’re looking at is lake water bubbling up through 4″ of slush from a 1″ diameter hole in the ice. Very disconcerting.

While the ice seems solid enough, it is disconcerting to say the least to be walking along on what appears to be a solid surface and then suddenly breaking through the crust to find yourself standing in 4″ of water. I would advise you use caution if you plan to venture out on the ice, and make sure to check the thickness frequently. Remember, because the dam’s gate is wide open, there’s a current flowing towards the channel which can result in thin ice in places. You were warned.

01 January 2016: December 2015 Water Level Chart Archived

I’ve archived the December 2015 Water Level Chart (at left). The most notable thing about it is that for the first time since the Clary Lake Water Level Order (WLO) was issued in late January 2014 the lake level is more or less where it should be this time of year. I already wrote about this back on December 27th so I won’t say more about it now. You’ll also notice the area of the chart between 0″ and 24″ below the top of the dam (left hand scale) is now shaded to make it easier to see when the lake level (red line) is within the allowable 24″ range.

We received 4.7″ of precipitation in December, a little more than normal. However, the total precipitation for the year of 36.8″ was still 7.2″ (or about 2 months worth) short of the 44″ we typically receive in a normal year. For comparison we were a little over in 2014 (46.9″) and a little under in 2013 (40.2″).

It remains to be seen where the lake level it going to go this winter. As of yesterday afternoon the gate was still about 95% closed and if it remains that way the lake level should remain in the “allowable” range until spring. Normally, with much of the winter precipitation tied up in the form of ice and snow, runoff is usually less during the winter months. With the hole in the dam letting out more water than the gate, it is entirely likely the lake level will fall below 24″ before long. Time will tell.

27 December 2015 VIDEO: Clary Lake Dam Flows

[dropcap]With[/dropcap] the lake level up around -22″ below the top of the dam, even with the gate about 95% closed there is still a lot of water flowing out of the lake. However, judging from this video, there is even more water flowing through the hole in the dam which is located above and to the left of the outlet pipe. The amount of water flowing through the cracks to the right is inconsequential.

27 December 2015: Lake Level now where it should be this time of year

The December 2015 water level chart for the day after Christmas showing the lake level has finally risen above -24″ below the top of the dam and is now in the allowable range for lake levels under the Clary Lake water level order.

[dropcap]Sometime[/dropcap] late on Christmas day the lake level, which has been gradually rising for the past few weeks, finally rose above -24″ below the top of the dam. This marks the first time since the Clary Lake Water Level Order was issued in late January of 2014 that the lake level has actually been at or near where it is should be for a particular time of year. Yes, it has been higher a few times in the past few years, and in fact it came within 12″ of the top of the dam last spring, but at that time it was still a foot short of where it should have been at ice out. And while it’s nice to see the lake more or less where it should be going into winter (at or near 2 feet below the top of the dam), we could really have used the water this past summer when the lake sat for months at historic lows, to everyone’s dismay. Continue reading →

10 December 2015: Maine VLMP Fall 2015 Newsletter now available

The Maine Volunteer Lake Monitor Program’s Fall 2015 newsletter “The Water Column” is now available for download or viewing online. It’s a good read.

The Clary Lake Association is a contributing member of the Maine VLMP and has been actively supporting the VLMP and collecting water quality data on Clary Lake since 1975.

01 December 2015: November 2015 Water Level Chart Archived

I’ve archived the November 2015 water level chart (at left). It is rather unremarkable, I suppose. The dam’s gate remains about 90% closed, or thereabouts. While we received enough rain during the month (2.66″) to bring the lake level up a total of 10.8″ it still fell 3.00″ (at the rate of about 1/4″ per day) over the course of the month because more water than required to supply the minimum flows is being released from the lake (see: Minimum Flows Explained). The net result was that the lake started out the month at 45.60″ below the top of the dam and ended up only 7.8″ higher, at -38.52″ below the top of the dam. While this is an improvement over the abysmal lake level we suffered with all summer, it is still way too low: the lake is currently almost a foot and a half lower than it really should be this time of year, going into freeze up.

And that’s a pretty important foot and a half of water that is still missing, as the pictures at left will show. I took these yesterday. While the channel is now full and the water has overflowed the channel banks some, most of the 300 acres of wetland at the outlet end of Clary Lake is still high and dry.

The only good news to report I suppose is that after a very dry summer and fall, the runoff multiplier is back to something approaching normal (4X) indicating that ground water supplies have been largely replenished from recent rains. That said, we haven’t fully caught up yet. With only 32″ of precipitation to date, we’re still about 7″ below normal and I doubt in the next month we’ll reach the annual average of 44″ for our area.

02 November 2015: New “Minimum Flows Explained” Page

Screen shot from the StreamStats program showing Clary Lake and the various streams making up the watershed.

I’ve been working on a page that explains minimum flows for a while now, and I guess it’s close enough to done for general consumption. I’ll update it from time to time as my understanding of this subject grows or new information becomes available. You’ll find the page under the Programs/Education main menu heading. Here’s a link to it:

Minimum Flows Explained

The picture at left is from the new USGS StreamStats hydrology mapping system, a really cool web-based application that lets you investigate watershed and stream flow data, from that small stream flowing through your back yard to the 145 square mile Sheepscot River drainage basin just like you knew what you were doing. I discuss the StreamStats program and how it might be used on the Minimum Flows Explained page.

Questions or comments are welcome. If anyone finds any errors or broken links please let me know.

31 October 2015: October 2015 Water Level Chart Archived

[dropcap]I’ve[/dropcap] archived the October 2015 water level chart (at left). The most notable thing about it is that sometime during the weekend of October 17/18 the gate on the dam was almost completely closed. The gate had been wide open since October 13, 2012. The gate still remains open about 3″ or 4″ or so, presumably so as to provide the minimum outlet flows calculated for Clary Lake and required in the Clary Lake water level order (WLO). Regrettably, the gate opening still allowed too much water to be released as the lake level continued to fall albeit at a somewhat slower than usual rate: the lake level dropped 0.15′ (1.80″) over the next 10 days (0.18″ per day; normal for this water level would be 0.25″ per day) until the 29th when we received 2.3″ of rain in one intense 12 hour storm. That the lake continued to fall after the gate was lowered clearly indicates that outflows from the dam exceeded inflows into the lake by measurable amount, which means too much water was being released. In my copious spare time I’ve been working on a post about minimum flows but it’s not ready so I’m not going go into them now. Minimum flows are fully explained in the Department of Environmental Protection Rules, Chapter 587: IN-STREAM FLOWS AND LAKE AND POND WATER LEVELS. While that’s not an easy document to wade through, it makes for interesting reading and fully explains the the purpose of minimum flows.

[dropcap]At[/dropcap] 45.84″ below the top of the dam, the lake level is higher now than it’s been since May 21st of this year. As high it seems that is still more than 2′ lower than it should be this time of year (no more than 2′ below the top of the dam). The 2.3″ rainstorm on the 29th brought the lake level up 8.76″ for a runoff multiplier of 3.8x which is still a little low indicating that runoff is somewhat reduced because the ground is still relatively dry and a lot of the rain is soaking in rather than running off. Average yearly rainfall for our area is about 42″ and as of the end of October, we’ve received only 29.41″ or more than 12″ less than normal, and only 2 months to make up the difference. Unlikely.

[dropcap]I[/dropcap] hate taking my boat out and I usually put off hauling out in the fall as long as I can. I think however I will take advantage of this increased lake level and haul my boat out tomorrow.