Category Archives: Technical Lake Stuff

10 September 2014: Updated Bathymetric Chart available

I’ve updated the recently released bathymetric chart with new contours using some additional data in the vicinity of the ledges at the northwest end of the lake and a few other rocks. The revised contour map now clearly shows both those ledges and the rock currently marked by a white buoy in the vicinity of the Whitefield/Jefferson town line near the north shore. Also, the 148′ and 146′ contours have been replaced with 1′ depth contours making this version of the chart more accurate in depicting the shallow water around the shoreline. I will, as time permits, further refine the underlying data.

If you’re not seeing version 0.2 dated 09/10/2014 (check lower left hand corner) try clearing your browser’s image cache.

Several people asked about getting a contour map superimposed on an aerial photograph. No problem! There are now two images available, a large scale one and a smaller more manageable image (click on the thumbnail at upper left). They’re also available on the Maps, Charts, and Graphs page. You’ll also find a .KMZ file there which you can load into Google Earth.

06 September 2014: New Clary Lake contour map finally available

I have finally gotten around to generating a contour map of Clary Lake using data collected by the Department of Environmental Protection during their September 2012 bathymetric survey. In addition to the high resolution image pictured at left there’s a smaller version available, and a 24″x36″ PDF which is quite large but which can be viewed or printed out at about any scale you wish. Feel free to download them, you’ll find them and the other files pertaining to the original bathymetric survey over on the Maps, Charts, and Graphs gallery. Each image has a link in the description field to the full-sized image.

The data set consists of 3,265 points with each point defining a 3-dimensional location on the face of the earth (i.e., the latitude, longitude, and water depth below the top of the dam). The depth was measured with a depth meter and each depth measurement was paired with the latitude and longitude of the point obtained via GPS receiver. The data in the form of a spread sheet was supplied to us back in April 2013 along with a colorized bathymetric map of the lake generated from the data. This map was a marked improvement over the original depth map of Clary Lake, prepared by the Department of Inland Fisheries & Wildlife back in late 1940s, but it lacks some real utility because it doesn’t show you what the bottom of the lake actually looks like- where the hills are, where the holes are, what the depth is at any given spot. According to the original depth map, the deepest spot in Clary Lake was only 23′ whereas we now know that the deepest spot is actually 29′ below the top of the dam. Continue reading →

01 September 2014: August water level chart archived

We’ve come to the end of another month, and I’ve archived the August water level chart. Despite the slightly less than average amount of rainfall in August (3.05″) and in spite of the fact that the dam’s gate has been wide open the whole time, the lake level remained in a fairly tight range of about ± 5″ for the month, starting out at a hair over 40″ below the top of the dam and ending the month a hair under 50″ below the top of the dam. In this range of water levels the lake tends to drop about 0.66″ per day, with the gate wide open. It doesn’t take much rain to bring the lake up a significant amount.

It is now just one month until October 1st, the date when the Clary Lake water level order is supposed to have been fully implemented. Given that Kelley has done absolutely nothing to implement the Order, it will be interesting to see what the DEP does when that date rolls around.

26 August 2014: Mapping DEP’s Bathymetric Data

In preparation for conducting a Water Level Survey sometime later this fall, I’ve put together an interactive map of the DEP’s bathymetric survey data using Google’s “Fusion Tables.” Each data point includes the latitude, longitude, and water depth in feet below the top of the dam. The data set consists of 3271 points, 6 of which I plugged in using data collected during our water monitoring activities. You can easily spot those as they fall in between the boat data tracks.

The deepest spot in the lake is about 28′ below the top of the dam. If your browser is failing to render the embedded map above, here’s a link to it:

Bathymetric Survey Fusion Table

The DEP conducted the field work in September 2012 and issued a colorized bathymetric survey the following spring. Eventually I will generate an actual contour map and also collect some additional data locating the rocks and ledges.

01 May 2014: April Water Level Chart archived

April brought the highest water levels we’ve seen in 3 years due in large part to melting snow and high runoff as a result of frozen ground though we ended the month with only 2.77″ of rain, well below the average about 4.39″. The water level started out around -40″ below the top of the dam on the 1st of the month and got as high as -18.6″ below the top of the dam on April 17th. It has been falling since then and ended the month at -29.3″. The dam’s gate has been wide open all month.

The deadline for submitting the Water Level Management Plan called for in the Water Level Order was today. We can only assume Mr. Kelley met the deadline. Stay tuned.

18 January 2014: Outflows from Clary Lake exceed 50 CFS

With the lake level higher than it’s been in several years, it follows that outflows from the lake should also be at levels not seen for quite some time. Well I had occasion to measure the outflow from Clary Lake this morning, out of curiosity as much as anything and sure enough, based on my calculations the current outflows as of the time of this writing are on the order of 83 cfs (cubic feet per second). The raw figure I arrived at was 98 cfs but it is customary to scale that figure down by as much as 15% to allow for flow losses resulting from friction on the sides and bottom of the stream which inevitably result in uneven water velocity and a lower overall flow value.

I estimate that about 55 cfs of water is flowing out of the dam’s outlet pipe and the rest of the water, about 30 cfs, is the result of water leaking through the hole in the dam and from seams on either side of the outlet. That there is a substantial amount of water leaking through the hole and cracks is apparent just by standing on the side of the road and looking at the downstream face of the dam. Here’s a short video I took this morning. What you can’t see in this video is the water leaking through the dam on the left side. It it essentially leaking across the entire face of the dam: Continue reading →

14 January 2014: Lake level continues to rise

Too bad it’s winter time and not boating time! The 2.3″ of rain we have received over the last 9 days has brought the lake level up over 23″ to -29″ below the top of the dam and it’s still raining. The lake has risen every day for the last 9 days and is now higher than it’s been since mid-June 2012. This makes for a runoff multiplier of 10x or 10″ of lake level rise for each inch of rain received. I attribute most of this to the time of year: with the ground frozen, less water soaks in and more runs off.

Lake levels normally fall during the winter due to a lack of precipitation but that’s not a problem this winter. I took the picture at left this morning when the surface of the lake was a little more than 30″ below the top of the dam, which is about 2″ above the water level at the dam. You can see water is now flowing out of the hole in the dam to the left of the outlet gate, indicating that the lake level has risen above the hole which is about -34″ below the top of the dam.

10 January 2014: Lake water level rises 13.7″ from last rain storm

The rain storm back on the 5th and 6th of this month dropped 1.37″ of rain on us. That rain has brought the lake up a total of 13.7″ for a runoff multiplier of 10x meaning that 1″ of rain brought the lake up 10″. This is impressive; normally the runoff multiplier is around 4x meaning an inch of rain brings the lake up 4″ but there is more runoff this time of year because the ground is frozen and little if any runoff soaks into the ground. The shape of the lake has something to do with it too: sometimes runoff causes the lake to get deeper, sometimes it causes it to get bigger, and sometimes it results in both happening at the same time. We’ve been in the “get deeper” range. Next up is the “get bigger” range where an inch of rain might only bring the lake up 2 or 3 inches but the size of the lake will increase substantially.

The lake level is now -39.2″ below the top of the dam or only 5.2″ above the hole in the dam. The lake is set to rise again fro the 1″ to 2″ of rain forecast for this weekend though I don’t think we’ll see a runoff multiplier of 10x, more likely 5x. That will bring the lake up to and likely above the hole in the dam which at last check was around -34″ below the top of the dam.

The thumbnail at left is a bit of a misnomer since the water level is a long ways from being “high” in my opinion. However Paul Kelley might have a conniption fit next time he stops by to check the Water Level Charts. The higher the better I say.

01 January 2014: Happy New Year & Water Level Year End Summary

Happy New Year everyone! It is the beginning of another year and I’ve posted the 2013 water level chart (at left) to the Archived 2013 Water Level Charts page. For some reason I can’t fathom (pun intended) the water level charts are not the most popular items on the web site, in fact only 2 people check them out with any regularity, David Hodsdon and Paul Kelley. David’s interest stems from having a scientific bent to begin with coupled with having measured the water level of Clary Lake off and on for the better part 30 years, and he just likes to admire a pretty chart. I suppose Paul has his own reasons for paying such close attention to the lake level. Perhaps he too just enjoys a pretty chart.

Initially I started measuring the water level of the lake to document the water level fluctuation and assess it’s impact on the environs of Clary Lake, to be used as evidence in support of our petition initiative. As with David, I also happen to have a scientific inclination as well as the technical skills and professional experience required so it has also served as a form of entertainment. Call me crazy. Since starting measuring the lake level however, it has become more of a ritual, something that I do with a measure of solemnity though it’s challenging to keep it up on a regular schedule during the winter due to the complications of snow and ice. It remains to be seen if I will continue with the practice once the Water Level Order goes into effect and water level measurements are being made at the dam; I expect I will at least initially because I want to investigate further the dynamics of runoff, water flow, and their effect on the elevation difference between the lake surface and the water level at the dam.

Some 2013 Statistics:
There are lots of ways to slice and dice the volume of data I’ve collected. Here are a few statistics for the past year. If anyone is interested in the raw data, just ask.

We started the year at -48.36″ below the top of the dam and ended slightly lower at -51.48″ below the top of the dam.
We received 40.23″ of precipitation in 2013 compared to 39.98″ for 2012, only 1/4″ difference.
The highest water level we saw in 2013 was -31″ on May 30th and the lowest was recorded on January 29th when it reached -61.68″ below the top of the dam. For comparison, in 2012 the highest was -19.08″ on June 7th and the lowest was -62.52″ on April 21th.
The average water level in 2013 was -48.9″ below the top of the dam compared to -45.7″ below the top of the dam in 2012.
In 2013, the dam’s gate was closed for only 10 days, from May 17th to May 26th during which time we received 4.33″ of rain which brought the lake up 25.56″ to -31″ below the top of the dam by May 30th, the highest the lake would get in 2013.
In 2013 the depth of water over the foot of the State boat launch was equal to or greater than the design value of 2.3′ for only 7 days during the last week of May.

Archived 2013 Water Level Charts

[Show slideshow]

January 2013

February 2013

March 2013

April 2013

May 2013

June 2013

July 2013

August 2013

September 2013

October 2013

November 2013

December 2013

Whole Year 2013

21 December 2013: Thoughts on the DRAFT Clary Lake water level order

finish-line-ahead A number of people have asked me for to explain the DRAFT Clary Lake water level order that was issued the other day. It is a very detailed and complex document with many subtle (and some not-so-subtle) elements and there is certainly a lot to ponder. I have reviewed it at length and will state for the record that I think the water level order is FANTASTIC. It is essentially what we asked for, and it was worth waiting for. I have begun preparing comments on behalf of the Petitioners to submit to the Department and which are due on or before December 30th, so I’m not going to go into a lot of detail now. I will however go over the highlights. I encourage everyone to read the actual ORDER and if you have any questions or comments, please send them to me.

The first 11 pages of the draft order constitute a Findings of Fact and a review of the evidence that the Department considered in making their decision. It is totally worth reading, especially C. “TITLE, RIGHT, OR INTEREST” on page 6 of 16. The WATER LEVEL ORDER proper starts on page 11. The major elements of the order are as follows: Continue reading →

14 September 2013: It’s been down so long it looks like UP to me!

Current Month Water Level Chart

Heavy rains over the past few days have brought the lake up 14.6″ so far from it’s low back on August 30th, most of the rise have occurred in the last 3 days. As of 7 AM this morning, the lake was at an elevation of 147.23′ or 40.92″ below the top of the dam. It’s still rising fast as the ground is saturated and the rate of runoff is high. Peak runoff typically occurs 24 hours after the end of the rain event which will be sometime tomorrow. Judging from the rate of rise in the last 24 hours and the trajectory of the curve I would expect to see the lake rise another 6″ or 8″ over the next couple of days and I wouldn’t be surprised if more than 50 cubic feet per second of water flowing out of the lake by Monday morning. Check out the Water Level Charts and guestimate for yourselves how high the lake will get.

The rapidly rising water has likely caught a few people by surprise, myself included. I woke up this morning to find my dock (which is sitting on stilts) barely above water and the ramp leading to it had floated away. I’ll be out later today searching for it and will have to move my dock in closer to shore lest it too float off in the night. Other people with moored docks and floats might find them inaccessible for the time being. On a brighter note, there were a number of people who were facing the predicament of getting their boats out of the lake. This lake level rise should make it easier. Currently at the state boat launch there’s 1.7′ of water over the foot of the ramp- still less than the design value of 2.3′ but a lot better than it has been. Tomorrow afternoon I would expect the there to be at least 2′ of water over the foot of the ramp if not more. Here’s your chance folks.

As welcome as this water level rise is, it’s important to note that the lake is still drastically low. At 40″ below the top of the dam the Great Meadow is still devoid of water and the vast wetland will offer no welcome haven to the flocks of migrating water fowl looking for a place to lay over, later this month. I’m not exactly sure how much rain we received over the past 3-4 days but we’re approaching 6″ total so far for the month, and it’s not even the middle of the month. Kelley is going to wish he had made repairs to the dam while he had the chance.

30 July 2013: [UPDATED] Clary Lake has officially entered an algae bloom state

David Hodsdon and Jack Holland completed their routine water quality monitoring task yesterday. I have updated the Clary Lake Water Monitoring Data page. David reports that the secchi disk reading he obtained yesterday (4.92′ or 1.5 meters) without question indicates that Clary Lake is experiencing an algae bloom, a fact that should not come as a surprise if you’ve been out on the lake lately. A lake is considered to be experiencing an algae bloom when the secchi disk reading is at or below 2 meters (6.56′). We’re well into bloom territory.

David has been in touch with Scott Williams of the VLMP about this issue and they may be sending someone out to independently assess the situation. The picture at upper left is from last summer’s bloom. It hasn’t gotten that bad yet.

I’ve written recently about algae blooms (here and here) and why we’re more at risk now because of the extreme low water conditions we’re experiencing. I’m going to get on the phone and rattle some cages.

[UPDATE]: I took a ride around the lake this afternoon- with bright sun shining down, I could just barely make out the bottom in 3.5′ of water off the end of my dock. I took a water sample just a bit ago and examined it under a microscope: it is loaded with Anabena cyanobacteria, the blue-green algae pictured at left that is largely responsible for freshwater algae blooms. The transparency of the lake water has deteriorated seriously over the last month: On the 1st of June the secchi disk reading was 10.1 feet; by the 19th it had dropped 2 feet and in the last 10 days dropped another 3 feet. Transparency is now less than 1/2 of what it was a month ago. They’re multiplying. Fast.

02 July 2013: Clary Lake Watershed Survey Base Map is Online

I’ve put together a Clary Lake Watershed Survey Base Map using Google Maps and watershed boundaries from the Maine Office of GIS for Clary Lake and Three Corner Pond. The map is basically a proof of concept effort, and a work in progress to boot as I’m still learning how to fit all the pieces together. The next step will be to put the 90 or so records of NPS (non-point-source) pollution sites from the original 2001 watershed survey into a database, geo-reference them with latitude and longitude, add pictures and updated information where necessary, and then finally, import them into the map. Continue reading →

01 July 2013: [UPDATED] Whitefield and Jefferson Parcel Maps for Google Earth

googleearth If you’re anything like me, you’ve been annoyed that the Maine office of GIS has not updated it’s Google Earth Parcels.kml file to include the recently completed Whitefield parcels map file. Whitefield parcels have been available for a while as a shape file, but that’s no help unless you have Arcinfo or Arcview. If you wanted to view Whitefield parcels in Google Earth, you’ve been out of luck.

No longer! I managed to get my hands on both Whitefield and Jefferson parcel maps. No need to load in every organized town in Maine, you can just load in the town you want. We’ll be making use of these when we get to work on updating the Clary Lake watershed Survey:

These links will open up in Google Maps. To add them to Google Earth, download them to your computer, then open them in Google Earth and save them to “My Places”. I’ll likely put these under the Charts & Data main menu heading at some point for easier downloading.

[UPDATE] I’ve also separated out the KML files for the Clary Lake watershed and the Three Corner Pond watershed (which flows into Clary Lake):

Clary Lake and Three Corner Pond Watershed (kml) file

These too will be useful when we get to updating the Clary Lake Watershed Survey. Like the Parcel files, these will open in Google Maps. Just download them and open them up in Google Earth, save them to “My Places.”

30 June 2013: Month-end Water Level Summary

June was the second month in a row with significantly above-average rainfall and this has helped keep the lake level up despite the dam owner draining 1.2″ of water out of it each day. It was the 6th wettest June in recorded history! We received approximately 6.13″ of rain, a good 2.6″ more than the average for the month of 3.56″. We started the month at -32.16″ below the top of the dam, fell to a low of -46″ on the 25th and then heavy rains brought it back up 5.5″ to 40.44″ at the end of the month. It we’d received the average rainfall for the month the lake would be at least a foot lower than it is today. It looks like this higher-than-average rainfall trend is going to continue for a little while; I’m torn between wanting more rain to offset the falling lake level and less rain to accommodate more outside activities.

Continue reading →

28 June 2013: The Clary Lake Watershed Survey and the NPS program

Back in 2001 members of the Clary Lake Association with the assistance of some DEP staff conducted a watershed survey to identify and catalog sources of non-point source pollution. Typically these were areas where soil was eroding and running into the lake: road side ditches, road shoulders, driveways, unprotected shorelines, unstable slopes, clogged, poorly maintained, or improperly installed culverts, etc. Money for erosion control measures was available under the State’s Nonpoint Source Water Pollution Control Grants (“319”) program. 90 sites were identified and categorized as to whether they were Low, Medium, or High priority and a grant was obtained and erosion control measures were implemented at a number of the high priority site

The NPS pollution and “319” grant program is still in existence today. At this summer’s Congress of Lake Associations’ 43rd Annual Maine Lakes Conference held last Saturday the 22nd at Colby College which I attended, Norm Marcotte of DEP gave a short presentation on DEP’s new NPS Tracker Program which is basically like the old NPS program with added spreadsheet functionality and computer mapping features made possible by such programs as Google Earth and Google Maps.

Continue reading →

26 June 2013: Rain! [UPDATED THRICE!]

You know it’s a slow news day when all I got to write about is rain but I’ve been doing a rain dance daily for a while now and it is finally paying off. This afternoon a beautiful storm cell formed up and moved in over Clary Lake and sat there. It’s still there. I just checked my rain gauges (a coffee cup and a dog food can out in the yard) and we’ve already received 1.375″ of rain and it is still raining steadily and shows no sign of letting up. The ground is pretty well saturated so I expect a good amount of runoff on top of yesterday’s rain… and more wet weather is forecast for the next couple of days. Keep an eye on the Current Water Level Charts.

[UPDATE 1] We ended up getting 1.5″ of rain out of that storm. Channel 6 weather report is calling for heavy rains tomorrow, as much as 2-3″

[UPDATE 2] Both David Hodsdon and Tim Chase got more like 0.9″ of rain out of yesterday’s storm, leading me to believe my 1.5″ measurement included “splash” since the rain was coming down pretty violently for a while. Certainly, 0.9″ of rain is more consistent with the lake level rise I observed this morning. I’ll be revising my rainfall amount and altering my make-do rain gauge setup.

[UPDATE 3] Don Norman called to tell me the he too got 1.5″ of rain yesterday. I guess that’s the meaning of “locally higher amounts.” I suspect that the total average rainfall, judging from the lake level rise, was between 1″ and 1.5″

17 June 2013: Temporarily Broken Subsystem

confused-monkey1 The water level chart update mechanism is broken. I’d hoped to get it fixed over the weekend but I guess I have to write a new script and I really don’t have the time right now. Sorry for the inconvenience. I’ll fix it when I get a chance. In the meantime, if you want to know what the water level of the lake is, go out and take a look!

UPDATE: Temporarily Broken Subsystem Permanently Fixed. I guess it wasn’t really broken in the first place.

01 June 2013: May Month End Summary

May started out dry but turned into a wet month indeed. On top of a dry April, we received no rain at all for the first 8 days of the month. The lake level started out -46.44″ below the top of the dam and fell at the average rate of 0.6″ per day to -56.52″ by the 17th of May at which point the dam’s gate was closed. Over the next 12 days we received 5.68″ of rain which brought the lake up 25.52″ for a runoff multiplier of 4.5x (4.5″ rise for each inch of rain) which is about what was expected. We ended the month at -31.08″ below the top of the dam. Average rainfall for May is 3.6″. The gate was reopened on the 27th and opened even further on the 30th. Runoff from the May rains has finally diminished to the point where the lake level has started falling again, having fallen just over 1″ as of this morning.

26 May 2013: The rain has ended!

swimming That was quite a stretch of wet weather eh? This afternoon as the sun started to break through I marveled at how long it has been since I’ve seen it, and how much rain we’ve gotten this month. April was a very dry month and May started out just as dry with no rain for the first 8 days. Since then we’ve received 5.5″ of rain which has so far brought the lake up 21.6″ with most of the rise occurring in the last 5 days. This afternoon the lake level sits at 34.9″ right at the bottom of the hole in the dam. As of this afternoon there was no water coming through the hole but as the lake continues to rise over the next few days that will change.

In any case, get out there and enjoy the (relatively) high water while it lasts. The lake hasn’t been this high since late June last summer and there’s no telling what to expect as the summer advances. The State boat launch is usable now and if you’re careful you won’t have any trouble getting your boat in the water. There’s 2.1′ of water over the foot of the ramp which is just a little shy of the design specification of 2.3′. Be mindful of the rocks- the water is only about 12″ deep 20′ off the end of the ramp.

I thought Kelley was going to open the gate this weekend in an attempt to keep the water level below the hole in the dam as he did last summer but he hasn’t touched it. Surprise, surprise. Last year he was ostensibly concerned about the impact of high water on the integrity of the dam and he did everything he could to keep the level -40″ or more below the top of the dam. Now maybe everything has changed; he has been referring to the dam as the “breached dam that formerly impounded Clary Lake” as if he’s given up on the useless, broken relic. Still, he’s trying to sell it and you’d think he’d want to keep it from deteriorating further especially considering he’ll probably still own it, and have to fix it, when the lake level order goes on.

Happy Memorial Day everyone.