Truesdale Lake  

These are some of the email reports and communications from Scot Evans from Truesdale Lake, James Gorman from Pond & Lake Connection, and others involved with the project. Putting selected parts up here for all to see what some of the discussion and learning is looking like.

Summary: Harold Ossher’s conclusion, following his evaluation of watershed research and flow data collected, was to use two 12” siphons plus the one prototype 6” siphon. This proved sufficient to stay ahead of this year’s wet October 8.2” rainfall total. (Average rainfall for October over the last three years is 7.7″ where OCT 2018 was 4.6” and OCT 2017 was 10.3″.)

When drawdown depth is achieved once again, I will gather the measurements of the siphons constructed on scene so that Cliff Munz can revise and convert my design drawing to CAD. 

Thursday 10/31/19 brought us a wicked double cold front for Halloween, delivering 1.01” of rain over 28 hours with strong wind gusts. In advance of the storm, James Gorman of P&LC restarted the west 12” siphon at 0930 EDT ~ providing a well timed response before the rain accumulated, before inflow exceeded outflow and before the two cold fronts passed with freezing temps. All three are flowing again at 1,100 CFM and the cause of the 12” shutdown was not identified. The lake gauge reading at restart was 2.2 feet below the spillway. 

Following the last report, the lake gauge was -2.0’ and ended the week nearly one foot lower at -2.9’ with siphon flow exceeding inflow after the 1.15“ of rainfall we received for the week.

Daily observations: 
TUE   10/29      LG -2.0’     Rob Cummings consolidates all reports, photos & responses to the lake’s website: http://truesdalelake.com/tag/drawdownreport/ in order to keep everything out in front of the inevitable questions.

WED  10/30      LG -2.1’     A steep pressure, temperature, & humidity gradient cold front approaches from the west.  THU   10/31      LG -2.2’     James Gorman restarts the west 12″ siphon ahead of the storm.. All siphons flowing.

FRI      11/1       LG -2.1’     LLR from 1.01” rain received. Inflow exceeds outflow. 

SAT     11/2.      LG -2.2’    30° F with first frost of the season. Outflow exceeds inflow for remainder of the week. 

SUN    11/3.      LG -2.4’     A long stick is caught in the east 12″ siphon intake, but it is still drawing water.

MON   11/4.      LG -2.7’     Whirlpool increases in diameter over west 12″ siphon intake which is shallower than the east siphon. This is still flowing but will shut down first.

Good morning Harold,

Here is my precip report for this year which includes JAN through SEP for a total of 37” (plus the 8” we received in OCT).

The report also shows the 30-year average for each month. (The thirty year average for OCT is 4.6” and we received 8.2” this past OCT, making your siphon determination of two 12” + one 6” right on target!)

I listed the links in preference order with your favorite format first.

–Scot

Many thanks, Scot, great to have this data.
BTW, I was wondering whether fins at and extending a bit beyond siphon intakes, like the bottoms of rockets, would help with the whirlpools? On the other hand, I think we reached target depth with the large siphons still running, so we might not want to keep them going longer.
– Harold

Hi Harold, 
This would very likely work to prevent whirlpools from forming above the perfect circle at the intake heads. I wonder if there exists such an attachment for PVC pipes. Maybe James will fabricate and patent his invention! Here are the baffle diagrams for rocket engine nozzles:

[. images did not download for me 🙁 .]

And you’re right, this would be a future consideration for James to consider for siphon improvements to our next drawdown attempt. 

He luckily installed the 12” intakes deeply enough so that the whirlpools shut them down right at target depth. The deep 6” siphon is still running and will help to keep up with the winter inflow and possibly enough to maintain the lake level close to target depth. 

If we get a lot of NOV rain and if inflow exceeds the effectiveness of the 6” siphon, I’ll ask James to restart the two 12 inchers. 
–Scot

These are some of the email reports and communications from Scot Evans from Truesdale Lake, James Gorman from Pond & Lake Connection, and others involved with the project. Putting selected parts up here for all to see what some of the discussion and learning is looking like.

October 29, 2019

Summary: Sunday 10/27/19 brought us the remnants of Tropical Storm OLGA, where we received 1.34 inches of rain in the twelve hours between 4 am and 4 pm.

During the 24 hours after the storm ended, the lake level rose 5″ even with all three siphons discharging a total of 1,100 CFM. Monday 10/28/19, the west 12″ siphon was observed to have stopped flowing; James Gorman was notified.

Mark Vibert of Main St recommended on the NextDoor site that we try to obtain aerial photos of the exposed lakebed during the drawdown target depth of three feet below the spillway deck. Rob Cummings responded and on Tuesday 10/15/19, he brought a borrowed drone over to my place, where we got some impressive aerial shots and video from several altitudes over the lake.

Ideal weather was enjoyed by the drone on this day before the bomb cyclone nor’easter dumped 3.34″ of rain and the lake level rose 17 inches over the next 3 days. Rob remarked that this demonstrates we’ll have no problem quickly refilling the lake this spring.

Daily Observations: 
TUE 10/22/19   LG -2.0 feet     Harold Ossher observes 6″ siphon not flowing (cause unknown) and one 12″ siphon still flowing at 500 CFM
WED 10/23/19   LG -2.0 feet    0.45″ rainfall received from weak coastal low
THU 10/24/19    LG -2.0 feet    one 12″ siphon matching the inflow rate
FRI 10/25/19     LG -2.1 feet     James restarts two more siphons and all three are flowing by 0845 EDT at 1,100 CFM
SAT 10/26/19    LG -2.3 feet     Siphon discharge exceeds inflow    
SUN 10/27/19   LG -2.4 feet     TS OLGA delivers 1.34″ rain and inflow exceeds siphon discharge
MON 10/28/19   LG -2.0 feet    LLR 4.8 inches as inflow continued to exceed siphon discharge. Equilibrium achieved about 1700 EDT. West 12″ siphon stopped flowing (cause unknown).

Aerial shots of exposed lakebed:: 
The three islands named on the interactive map are WAXWING (north), ANT (center) and PIRATE (south).

A new set of islands became visible during the drawdown. I propose that this set be named BOAT PRANG ARCHIPELAGO or LARA’S GALAPAGOS.

Here are a few aerial photos of the lake from the many taken. I’ll post more this week on a NextDoor thread.

Thanks Scot for this update

Really interesting to watch how this all unfolds

Thanks again

David

Yes, thank you, and to you and Rob for the really interesting photos.
I’m not surprised the lake level rose after significant rain despite the siphons. The watershed is so big that there’s no way they can keep pace during periods of peak inflow. But once all of them are running again, the level should go down fairly quickly again.

– Harold

Love the photos! The “Galapagos” is an inspiring bird sanctuary attracting all manner of feathered friends – picture attached. 

-Lara

These are some of the email reports and communications from Scot Evans from Truesdale Lake, James Gorman from Pond & Lake Connection, and others involved with the project. Putting selected parts up here for all to see what some of the discussion and learning is looking like.

October 21, 2019

Rain from the strong nor’easter bombogenesis (at least 24 millibar drop within 24 hours) began at 2 pm Wednesday 10/16/19 and ended just after midnight where we received 3.34”of rain. On Thursday 10/17/19, we received a small amount of wrap-around moisture with an additional 0.04” or rain.

At the beginning of the storm, the lake gauge (LG) was 2.9 feet below the spillway deck where it had remained for the past seven days. Rob Cummings also took excellent video and still shots with his drone of the exposed lakebed at this drawdown target level before the storm arrived. Will send some of his choice photos later this week.

Lake Level Rising (LLR) occurred rapidly and rose 17 inches in the 40 hours during and after the storm. This is a multiplier of 5+ times the rainfall.

Keeping in mind that the lake contour is a cone, it would take some severe calculus to convert the rise to the vertical contour of a cylinder.

James Gorman with P&LC arrived early on Friday 10/18/19 and restarted one 12” siphon and the 6” siphon at 8:30 am, which began Lake Level Lowering (LLL) as the inflow from the storm steadily decreased.

Here are the readings taken at the beginning and end of the storm, then every four, eight or sixteen hours thereafter.

10/16      1400 LG -2.9 feet datum (before rain began and followed by 3.38” rainfall from the storm)

              2400   LG  -2.5 feet or LLR     4.8 inches (Immediate Rise)

10/17      0800   LG  -2.2 feet or LLR     8.4 inches

              1200    LG  -2.0 feet or LLR  10.8 inches

              1600    LG  -1.8 feet or LLR  13.2 inches

               2400   LG  -1.6 feet or LLR  15.6 inches

10/18       0800   LG  -1.5 feet or LLR  16.8 inches (Peak Rise &
siphons energized – flowing 617 CFM)

               2400   LG  -1.5 feet or LLR  16.8 inches (remains peak
as siphons match inflow)

10/19       0800   LG  -1.6 feet or LLL  15.6 inches

               2400   LG  -1.6 feet or LLL  15.6 inches

10/20       0800   LG  -1.7 feet or LLL  14.4 inches

               2400   LG  -1.8 feet or LLL  13.2 inches (received
0.33” rain from a weak offshore nor’easter)

10/21       0800   LG  -1.8 feet or LLL  13.2 inches

Thanks Scot! This tells me we won’t have a problem refilling the lake is the spring!

-Rob

Good point, Rob! Meanwhile, it’s good to see the (reduced) siphons doing their job again. Thanks for the detailed measurements, Scot, it’s very helpful to have this tracking of what is happening.
– Harold

These are some of the email reports and communications from Scot Evans from Truesdale Lake, James Gorman from Pond & Lake Connection, and others involved with the project. Putting selected parts up here for all to see what some of the discussion and learning is looking like.

October 15, 2019

Good afternoon James, 

Starting the 6” siphon remains at your convenience. We are maintaining the target depth, where evaporation is nearly keeping up with the inflow. 

During the last 9 days, we received 1.03 inches of rain which was mostly absorbed by the dry ground of West Mountain and surrounding area with little inflow from the Boway Stream:

Summary: over the past two weeks with no siphons operating, we received 1.5 inches of rain with a lake level rise of 3 inches. This is a multiplier of 2 times the rainfall amount. 

We remain in drought conditions with ground absorption and evaporation the overriding factors beyond inflow. When the ground becomes saturated, we will see the multiplier rise rapidly. 

Great. Thanks for the update. I keep driving by every time I am in the area. I am scheduled to hook up the 6″ pipe on Friday. I will probably also fire up a 12″ due to the fact that we will probably get a good rain here today and tomorrow. 

In a perfect world when is the “end date” of the draw down. 

-James

James –

We finally have some impressive storm results to give you after the 3.34” of rain we received last night.

When the storm ended at midnight the lake rose 5.5 inches. 

Eight hours later, my reading just now shows a rise of 9.0 inches. 

So your plan to hook up the 6” and fire up the 6” and one 12” tomorrow is excellent. 

Your plan is great timing too, since by the time you get them flowing, I will have had four full eight hour periods after rainfall ended to report to Harold. 

-Scot

(more detail on this storm is in next report)

These are some of the email reports and communications from Scot Evans from Truesdale Lake, James Gorman from Pond & Lake Connection, and others involved with the project. Putting selected parts up here for all to see what some of the discussion and learning is looking like.

September 28, 2019

The lake level increased 4” since the target depth was reached on Sunday 9/22/19. So one week later, James Gorman and crew correctly restarted the two 12” siphons to keep the drawdown ahead of the rain coming in October. 

Remember this most important piece of information: For every inch of rainfall we receive, the lake level increases 12”! Remember that none of this inflow will go over the spillway until the lake fills up – at this rate. 

So, with the two 12” siphons P & LC started on Thursday, we once again reached the target depth of 3’ below spillway at noon today. It will draw down just another six inches and the siphons will shut down once again by themselves. 

After energizing the 12” siphons, James Gorman disassembled the 6” siphon intake, in order to take it back to his shop and lengthen it so that the 6” inch siphon will be started to keep up with the drawdown target depth and rainfall. He will energize one or two of the 12 inch siphons if necessary, in the event we receive significant rainfall. Pond and Lake Connection is doing everything right. 

I took pictures of the south end of the lake and attached them below. I really feel for the people at the south end especially and also at Vreeland area where the river brings in huge amounts of silt since the holding lagoon there is full and no sediment has ever been extracted as agreed, to my knowledge.

Also the North Cove is in similar shape. These are the critical areas that Cliff Munz circled in red on his chart.

Rather than dredge these areas it would be less expensive and make more sense to bring in big machinery to dig them out during a drawdown after necessary permits are obtained. There are several non- built properties on the lake with owners willing to take the landfill. I can secure their agreements if it comes to this. 

Neil Cutler on TLD has requested a dumpster for lake trash, but the dumpster will have to be restricted to dumping in one reserved and announced day and monitored so people don’t bring in construction debis. And I know this will happen, so I volunteer to arrange the dumpster, make the announcements and be that monitor. The best rates are from Belardinelli in Danbury. I recommend the 30 yard container. 

• 10 yd: 1.5 tons $275 13 x 8 x 4
• 15 yd: 2.5 tons $375 15 x 8 x 4
• 20 yd: 3.5 tons $475 19 x 8 x 5
• 30 yd: 4.5 tons $600 20 x 8 x 6

-Scot

These are some of the email reports and communications from Scot Evans from Truesdale Lake, James Gorman from Pond & Lake Connection, and others involved with the project. Putting selected parts up here for all to see what some of the discussion and learning is looking like.

September 23, 2019

The target depth was reached at 1 pm yesterday (sept 22) with three feet below spillway and four feet total drawn out by the siphons. As of Sunday 9/22/19 at 1:00 pm, all siphons have naturally shut down. 

Please schedule any day this week where you can lengthen the 6″ siphon to a four of five foot depth below spillway deck, so we can maintain the three foot depth as you recommended. (It needs to be four to five feet below spillway height since the vortex shut it down when it swirled 8″ above the intake.)

Here is a photo & video of the EAST siphon breathing air through the collapsing rubber coupling just before it shut down on Friday night.

I have pulled many fish hooks, lures, sinkers and line by cutting the geotextile fabric and dislodging the stone riprap then replacing it, so your crew should have a good suface to install the extra pipe. Here’s a summary of the drawdown progress:

• The 1st foot of water from summer level to winter level was drawn out by three operating siphons in 60 hours.
• The 2nd foot of water from spillway height  to -1.0′ on the gauge was drawn out by three operating siphons in 60 hours.
• The 3rd foot of water from -1.0′ to -2.0′ on the gauge was drawn out by two operating siphons in 70 hours. (6″ siphon shut down 9/16/19)
• The 4th foot of water from -2.0′ to -3.0′ on the gauge was drawn out by one operating siphon in 100 hours. (east 12″ siphon shut down 9/20/19)
• The west 12″ siphon shut down at target depth on 9/22/19.

It was entertaining to watch the last of the siphons shut down at the same time that the lake reached exactly three feet below spillway height.

All’s well here and thanks again for the beautiful construction!
-Scot