Category Archives: Technical Lake Stuff

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.

01 October 2015: September 2015 water level chart archived

I’ve archived the September 2015 water level chart (at left) which clearly shows the impact of the recent drought conditions. The lake level averaged -65.86″ below the top of the dam and never varying more than ±1″ from that level until the last day of the month when we received over 4″ of rain in less than 24 hours. By 7:30 PM on the 30th the rain had stopped but it was still way too windy to get an accurate measurement of the lake level though it appears it had come up about 12″. No doubt today will see an additional rise in lake level but I wouldn’t expect it to come up too much more because a lot of what would normally have run off into the lake ended up soaking into the very dry ground.

And just like that, we went from 1.52″ of rain to 5.52″ for the month. The extreme runoff has resulted in considerable lake sedimentation resulting from shore erosion and stream bed scouring. If the lake level were where it should be this time of year (between 1′ and 2′ below the top of the dam) this rain event would have had little impact on lake water quality. I shot a short video yesterday afternoon showing a flooded stream entering the lake, which I’ll post later.

07 September 2015: Is Metaphyton growth in Clary Lake a cause for concern?

If you’ve spent any time on Clary Lake this summer you’ve seen those green “cotton candy” clouds of algae floating around near the shore. These blooms of algae are most commonly found in shallow (littoral) areas of lakes and are comprised of free-floating masses of filamentous green algae (primarily Spirogyra, Gonium, and Zygnema) and is referred to collectively as Metaphyton. Because they’re unattached (free-floating) they tend to move around with wind and water currents so one day you might not see any on your shore line and the next the bottom could be covered with it. Metaphyton masses will often get entangled with sticks, rocks, mooring lines, and other pond plants and then they don’t move around but remain in one place. Scientists are still learning about what influences the growth of metahphyton and its significance and potential impact on water quality besides the obvious “yuck” factor. Metaphyton can form dense mats that trap gasses given off by plant decomposition, causing them float to the surface where wind and waves cause them to break up and dissipate. Continue reading →

01 September 2015: August 2015 water level chart archived

I’ve archived the August 2015 water level chart (at left), and what a chart it is. One glance and you can see that the water level hardly moved. For the entire month the lake level never rose above -63″ below the top of the dam and on August 7th it reached -65.16″ below the top of the dam, the lowest level I’ve ever recorded. The lake is so low in fact that water is no longer flowing out of the lake into the outlet channel and hasn’t been since early July; there’s a trickle of water flowing through the open gate in the dam but it is coming from ground water and springs in the meadow area. It’s actually been at or below -60″ below the top of the dam since July 10th. This makes it the longest stretch of the lowest water levels we’ve experienced in the last 4 years. It’s gotten almost this low before, but it has never stayed this low for this long.

The low water condition has been exacerbated by the near-drought conditions we’ve experienced so far this year. As of the end of August we had received only 18.88″ of precipitation for the year compared to 32.83″ on this date a year ago. As a result, because the ground is so dry, there has been no absolutely no runoff as the result of what little rain we have received. To make matters worse, because of the topography of the shoreline around lake, when it does rain the lake doesn’t so much get deeper as it does bigger. This then explains how last August 11th and 12th when we received 2.29″ of rain, the lake only came up 1.92″ total. This defies logic, but as those of you who have stuck sticks in the mud on your water front to mark where the water line is can attest, it ain’t moved.

This extended period of excessively low water levels has severely restricted everyone’s use and enjoyment of Clary Lake even more than usual, not to mention the ongoing impact on wildlife habitat, and water quality. There will be consequences.

10 August 2015: Drained Beaver flowage adds water to Clary Lake

A funny thing happened over the weekend: the lake level which has been falling a consistent 1/4″ daily (due to evaporation only) had, without warning, risen 1/4″ by early Saturday afternoon without us having received any rain at all… This situation had me thinking I’d made a mistake in measuring the water level until I discovered early that evening that the marsh on the south side of Route 126/215 at the primary inlet to Clary Lake which had been recently flooded by beavers was draining into Clary Lake. The picture at left shows the inlet of the culvert well plugged by sticks and mud on Thursday afternoon with the water level less than a foot from the top of the culvert. Sometime early Saturday morning someone, most likely a Town of Jefferson work crew, brought an excavator to the site and dredged out the blockage. Continue reading →

July 2015 Water Level Chart archived

July 2015

I’ve archived the July 2015 water level chart. The most notable thing about it is that it shows the lake level fell to 60″ below the top of the dam on the 9th of the month and remained well below that mark for the rest of the month. It has never been this low for this long. And no wonder given how little rain we’ve received this year: as of July 31st we have received a total of only 15.29″ of precipitation since the beginning of the year. Last year on the same date we had received 29.74″ or almost twice as much. The lake level also fell to a 4 year record low of 62.64″ on July 18th (see 21 July 2015: A new high in lows“). It has since fallen even lower than that, ending the month at 63.48″ on the end of the month.

It’s been so dry this year and especially this past month that when it does rain, very little of it runs off into the lake because most of the precipitation that falls on the ground is being soaked up. This fact, in combination with the topography of the exposed shoreline around the lake, results in a runoff multiplier less than 1x meaning that an inch of rain will bring the lake up something less than an inch. This doesn’t really make sense until until you realize that as the lake level rises it also spreads out, increasing the area of the lake. In other words, when it rains the lake gets bigger, not so much deeper. We’ve seen this phenomena before. How cruel is that?

Because of the berm at the outlet of the lake, very little water is actually leaving the lake now and flowing down the channel to the dam; most of the water that you see flowing out through the dam these days is seeping out of the ground in the meadow area itself, which is quite wet, and also coming in from Clark’s Meadow Brook. As a result, most of the ongoing daily drop in water level (about 1/4″ per day) is due to evaporation.

21 July 2015: Lake level reaches a new high in lows

I don’t need to tell anyone that the lake level is low, that much is obvious. However the lake is now lower than anyone has seen it in more than 54 years judging from a picture taken back in the summer of 1961, and that seems like something worth telling people about. On April 21, 2012 the lake fell to a then-record low of -62.53″ but as of the other day, the lake level had fallen even lower than that, to -62.64″ below the top of the dam, where it sits now. I went over to the State boat launch with my camera to take yet another picture of how useless it is and found the water level had fallen off the end of the ramp. Continue reading →

10 July 2015: Declining water quality, by the numbers [UPDATED]

Get ready for an algae bloom. Jack Holland and I went out and conducted our regularly scheduled water quality monitoring today and the secchi disk reading was only 2.50 meters (8.20′), down from 3.16 meters (10.36′) just two weeks ago. A lake is considered to be experiencing an algae bloom when the secchi disk reading is 2.0 meters or lower. We’re within only 1/2 a meter (1.6′) of that threshold now, and it’s only July 10th. Last year on the 18th of July the secchi disk reading was 3.25 meters (10.66′) and we didn’t approach the 2.0 meter threshold until almost the end of July. We’re good two to three weeks ahead of last year.

I’ve noticed over the past 4-5 days the lake color has gotten decidedly murky and brownish/green but I was still surprised the secchi disk reading so low. I probably shouldn’t have been given how dry it’s been and how low the lake is as these factors contribute to conditions conducive to the growth of filimentous cyanobacteria (aka blue green algae) which are responsible for algae blooms. Once the conditions are right for cyanobacteria to start multiplying, their growth can be explosive.

We’ll take a water sample for phosphorus testing during our next water quality monitoring session in 2 weeks. Phosphorus tests cost $25 a pop to get them analyzed by the State so we usually only do 3 tests per year.

[UPDATE: 7/14/2015] Based on the latest secchi disk reading taken about 1/2 hour ago, Clary Lake is officially having an algae bloom. The reading was 1.95 meters (6.40′). As mentioned above, a reading at or below 2 meters is considered to be an algae bloom.

08 July 2015: Lake shore owners concerned about invasive aquatic plants [UPDATED]

Last week I noticed some large and extensive mats of a green pond weed over by my shoreline in about 2′-3′ of water, thick enough to foul my trolling motor and bring my boat to a halt. I collected a sample and identified it as Elodea or American water weed (or Common Pond Weed). I was therefore not particularly surprised when Thomas Gillette showed up at my house yesterday with a shopping bag full of this plant, concerned that Clary Lake might have an invasive plant infestation underway. Thomas told me that Butch Duncan had brought it to him, saying that there were thick mats of it over in the cove on the north side of the lake by Duncan Road.

I reassured Thomas that this was not an invasive species. We’ve had this plant growing in Clary Lake forever but it’s always remained under control. You’d see a few pieces of it wash ashore from time to time or you might see patches of it up in the channel. Recently however, conditions around the lake have become quite conducive to this plant’s rapid growth in areas where it was not found before. Elodea is not a recognized invasive plant species but under the right conditions it can and does become a nuisance, clogging shallow water areas with thick mats of vegetation. Elodea likes nutrient-rich water down to several meters (5′-7′) in depth, plenty of sunlight, water temperatures between 10° C and 25° C and a soft, silty or muddy bottom where it’s thin wiry roots can get a good foot hold. You won’t find Elodea on a rocky or gravel bottom. With the water level down 5′ and 50% of the volume of the lake gone, conditions around Clary Lake are near perfect for this plant’s growth to explode: the reduced lake volume increases the concentration of nutrients in the water and the lowered lake level allows sunlight to reach down to silty/muddy areas that would normally be under 7′ to 10′ of water where Elodea wouldn’t normally be found, or be able to survive. Now our shallow water areas are a perfect habitat for Elodea.

Continue reading →

June 2015 Water Level Chart archived

6 waterlevelchart_June2015 I’ve archived the June 2015 water level chart. The lake level remained in a fairly tight range for the whole month, fluctuating only ± 3.7″ and ending up the month a little off its lows at -57.36″ below the top of the dam. It fell to 62″ below the top of the dam on June 20th, only the second time in 4 years it has gotten that low. In comparison, during the month of May the lake level fell precipitously at over 1″ per day, for the entire month. Despite the above average amount of rain we received in June (5.46″ compared to an average of 0nly 3.54″) the lake level remained largely unaffected because so much of the precipitation soaked into the ground rather than running off into the lake. As a result, the runoff multiplier was closer to 1X to 1.5X rather than the normal 4X multiplier. May’s rainfall total was so far below average (only 0.60″ compared to an average of 3.7″) that even with all the rain we received in June, we’re still several inches below normal.

The state boat launch remains largely unusable except for carry-in traffic and small boats if you’re able to manhandle them on and off their trailers and are willing to drag them across the rocks and shallows to get to and from deeper water; not many people are. I’ve seen a number of vehicles pull into the launch area with boats on trailers only to leave after seeing exposed rocks off the end of the ramp. Can’t blame them. As a result, boat traffic on Clary Lake this summer is noticeably below normal. Anyone who does manage to get their boat launched has to contend with shallow water and rocks where you least expect them. Only a few of the hazards are marked, leaving vast areas too shallow for safe boating to surprise the unfamiliar boater.

There is ample evidence around the lake of the impact of the ongoing severely low lake levels besides an unusable boat launch, and rocks sticking out of the water. As a result of fluctuating water levels, the loons that call Clary Lake home have not even bothered to try nesting this year, or last. Their last successful nesting attempt was back in 2008. Even more damaging to the ecosystem is the loss of 350+ acres of sensitive, high-value wetlands and the shallow-water littoral zone around the edge of the lake so important for lake health and for bird, fish, and animal habitat. Gone.

13 June 2015: Using the Clary Lake depth map on the lake

When I first posted about the Clary Lake Depth Map last week I mentioned that you could use it with a GPS in real time on a tablet or smartphone. I should have said “in principle” because at the time I actually hadn’t tried it yet… A couple of people asked me about this and I had to tell them that I was still working on it. Well now I have tried it, and I thought I ought to post something more about it. It turns out it DOES work (I knew it!) but it did take a little doing to get it working well out on the lake without an internet connection.

The tricks includ saving the map for “offline use” (see Google Maps “tips and tricks” for how to do this) turning off automatic screen rotation so the app doesn’t try to reload the map, not trying to zoom too much (people with a 3G or 4G data plan from their service provider and who can access the internet anywhere won’t have these issues). Above is a screenshot from my Nexus tablet I took the other day showing the Clary Lake depth map overlaid on Google Maps with GPS positioning enabled (the blue dot with the arrow head and ring around it shows where I was at the time, on my deck). As you move around the lake, the GPS updates your location shown on the map which makes it easy to locate a rock, ridge, or slope where you’re likely to find fish hanging out. How cool is that? This combines things I enjoy a lot, fishing, computers, and using maps. Now if I could just figure out how to convert the depth map into a format that can be uploaded to a Lowrance Mark IV depth finder, I’d be truly happy. You’d think this would be easy.

If you want to give this a try using your smartphone or tablet, first make sure you have location services enabled then copy and paste the following URL into your browser, and head out onto the lake:

https://www.google.com/maps/d/viewer?mid=zb1eVxqneIkk.kyhM9B_EX4Ks

If you try this let me know how you make out. Remember to subtract the current lake level (in feet, presently about 5′) from the depths shown on the map. This will also give you a good idea of areas around the lake to avoid due to lack of water.

05 June 2015: Interactive Clary Lake Depth Map v2.0 now available

Fullscreen capture 652015 114727 AM.bmp (Mobile)

Clary Lake depth map v2.0 (click on the image to view the page)

I’ve added an updated version of the Clary Lake depth map to the site using an embedded Google Map. The page is located under the Charts & Data main menu heading and is entitled “Clary Lake Depth Map” and it’s pretty cool if I do say so myself. This new map has a contour interval of 1 foot and uses dynamically rendered depth labels so as you zoom and pan around the map the labels redraw so you can usually tell the depth of any line you’re looking at. If not you can click on any contour lines and find its depth. The depth contours are also color coded so the darker the line, the deeper it is. There are 8 color ranges, some of which are a little hard to distinguish. Click on the Legend link on the top left corner of the map to see them (if you can’t see the legend symbol, try resizing your browser window). I’ve also added a few colored dots marking rocks and ledges and plan to add a few more as time will permit. You can click on them as well to find out the depth. You can also change the map to use a satellite image instead of the standard terrain base map. Unfortunately, this can make the blue depth contour lines a little hard to see; when I have some time I’ll prepare a map with depth contours intended to be viewed on a satellite image. There are a lot of neat features available with Google Maps and I’m still learning, so expect the map to go through some changes.

Continue reading →

May 2015 water level chart archived

May 2015 Water Level Chart

Behold the May 2015 water level chart. After rising to within 12″ of the top of the dam on 23 April, the lake has fallen steadily to about where it was before the spring melt started back on March 24th. At that time the lake level was at -57.12″ below the top of the dam. At -56.04″ we’re within an inch of that now.

For the month of May, the lake level dropped 35.76″ in 31 days, or about 1.15″ per day, a rate that was negatively affected by the lack of rain. Normally we get about 3.7″ of rain in May which would have offset the fall in the lake level considerably, however this year we received only 0.60″ of rain for the entire month. As a result, as a quick look at the chart will show, the lake level fell every day. Also, because it was so dry, evaporation contributed significantly to the daily water level drop. Since the high on April 23rd, the lake level has fallen 43.32″ in 39 days or 1.11″ per day. Normally you would expect the rate of fall to slow gradually as the level dropped. Below 48″ the usual rate of fall is about 1/2″ per day.

We can all take comfort in knowing that this ongoing ecological disaster won’t be ongoing forever. It will be a little while longer, but normal water levels WILL BE RESTORED.