Truesdale Lake

January 30, 2020
by rob
Comments Off on Notice of Consent – Annual Mailing Sent to Riparian Homeowners

Notice of Consent – Annual Mailing Sent to Riparian Homeowners

These annual notices were sent via US Mail to all riparian (lake-side) homeowners as required by New York State law. They are a continuation of our annual lake management program, including treatment, dating back over 50 years undertaken when we engaged Pond & Lake Connection as our new lake manager.

Date of Notice: 1/22/2020

Dear Riparian Property Owner:

To control the excessive growth of various aquatic weeds, at Truesdale Lake, The Pond Connection proposes to conduct an application of the aquatic herbicide/algaecide Cutrine Ultra, Green Clean Pro and Clipper. A copy of these labels can be found at http://www.thepondconnection.com. We anticipate the treatment to occur throughout the summer, only when necessary and will proceed only after the riparian owners obtains a permit for the treatment from the NYSDEC.

This pesticide application will only occur if sufficient aquatic vegetation is present to warrant treatment and under favorable weather conditions. Prior notification of the exact dates of treatment can be provided by contacting The Pond Connection as listed below. The pond/lake shoreline will be posted with signs the day of treatment.

As an affected riparian owner/user, you have the right to consent or object to the restrictions of water use resulting from the proposed treatment. The water use restrictions associated with use of the above pesticides are below:

Swimming and bathing are prohibited for: No Restrictions
Fishing and/or fish consumption is prohibited for: No Restrictions
Livestock watering is prohibited for: No Restrictions
Irrigation or spraying of agricultural crops is prohibited for: Cutrine Ultra:N/A, Green Clean Pro: N/A Clipper: 5 Days.
Use of water for human consumption is prohibited till: Cutrine Ultra: 200ppb, Green Clean: 50ppb, Clipper: 50ppb.
Use of water for domestic purposes is prohibited till: Cutrine Ultra: 200ppb, Green Clean: 50ppb, Clipper: 50ppb.

Human consumption and domestic purposes restriction refers to the water body being used as your primary and sole use of water for drinking and culinary purpose. Potable water use is not incidental contact with the water such as swallowing a mouthful of water while swimming.

You have twenty-one (21) days to respond to this notice. If you wish to object to the proposed treatment(s), please file a written document stating your objection to the proposed treatment and the water use restrictions resulting from the treatment.

Send your comments to the Bureau of Pesticide Management listed below:

NYS Department of Environmental Conservation, Region 3
Bureau of Pesticide Management
21 South Putt Corners Rd, New Paltz, NY 12561

If you wish further information about the treatment, or wish information on the exact dates of the pesticide application, please contact the following person:

The Pond and Lake Connection, 1112 Federal Road, Brookfield, CT
Name of Contact Person: James Gorman
Telephone Number: 845-798-9383 Email: james@thepondandlake.com

If you do not respond to this notice, your lack of response will be considered consent to the proposed treatment. If you have any questions on the permitting process, please contact the Department representative listed above.

January 14, 2020
by rob
Comments Off on Drawdown Report 12

Drawdown Report 12

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.

Today, with all siphons flowing, the lake level is 2.3 feet below the spillway ramp and descending. The lake froze completely on December 20th with ice up to three inches thick and 80% of the lake was melted by January 7th, allowing for a much cleaner fifth and final descent to target depth. If we are lucky, the lake will again freeze in January when the siphons shut down with lake level at three feet below the spillway.

Also today, the dry hydrant intake head became exposed for the fifth time during this season’s drawdown. The Fire Commissioner’s contractor may agree that this Monday through Thursday, 1/13 – 1/16, with above freezing temperatures, would present an ideal opportunity to install an extension in order to lower it vertically at least two feet more.

And finally, today marks a milestone confirmation of the calculations from our resident mathematician, Harold Ossher, in that the two 12” siphons and one 6” siphon, installed and maintained by James Gorman of P&LC, have demonstrated that they are ideal in size and number for reducing the lake’s level during the 30-year average rainfall of 4.4 inches per month within the three-month drawdown period – October, November and December.

This conclusion is reached from observations in these last two reporting periods, in that all three siphons have been flowing consistently for the past 30 days – WED 12/11 to FRI 1/10 – with inflow from 4.38 inches of rain, which represents one drawdown month.

With all three siphons flowing uninterrupted, the lake’s level increased after each rainfall from 1.3 feet below the spillway up to two and a half inches above the spillway, and it descended during the dry days with a net decrease of 12 inches to 2.2 feet below the spillway.

DD Month Rain/SWE 30-year 3-foot below Spillway

2019-2020 inch total inch AVG Target Depth achieved

SEP (dry) 0.6 4.5 1^st – Sunday 9/22

OCT (wet) 7.4 4.6 2^nd – Monday 10/7

NOV (avg) 3.1 4.4 3^rd – Tuesday 11/7

DEC (wet) 6.3 4.1 4^th – Friday 11/29

JAN (dry) (0.4 to date) 3.7 5^th – Friday 1/17

December 2019 was quite wet and matched last year’s December 2018 total of 6.3 inches of rain.

Some of the desired results from the drawdown, like weed tuber destruction and soil desiccation, may be evident as early as the end of next summer. Other long-term benefits, such as silt compaction, will take more time and can be assessed later on.

In the meantime, lakeside residents have made excellent progress in cleaning up their newly exposed beaches, removing broken glass and other hazardous objects, and disposing of trash, including discarded equipment, at their own expense.

Many neighbors have sent photos of their newly cleared lakefronts to be included in the Truesdale Lake archives.

This is my final report for the 2019/2020 winter season drawdown. Rob Cummings has compiled all of the drawdown reports and replies in one link on the Truesdale Lake website > http://truesdalelake.com/tag/drawdownreport/

Scot

Daily Observations during this reporting period:

12/23 MON LG -0.5’ Outflow exceeds inflow. Lake 100% frozen with 3″ ice.

12/24 TUE LG -0.7’ Outflow exceeds inflow.

12/25 WED LG -0.9’ Outflow exceeds inflow.

12/26 THU LG -1.1’ Outflow exceeds inflow.

12/27 FRI LG -1.3’ Outflow exceeds inflow.

12/28 SAT LG -1.5’ Outflow exceeds inflow. 0.01” rain

12/29 SUN LG -1.7’ Outflow exceeds inflow.

12/30 MON LG -1.7’ Inflow matches outflow. 0.63” rain

12/31 TUE LG -1.5’ Inflow exceeds outflow. 0.44” rain

1/1 WED LG -1.3’ Inflow exceeds outflow. 0.02” SWE

1/2 THU LG -1.3’ Inflow matches outflow. Lake ice continues to melt.

1/3 FRI LG -1.5’ Outflow exceeds inflow. 0.07” rain

1/4 SAT LG -1.7’ Outflow exceeds inflow. 0.11” rain

1/5 SUN LG -1.7’ Inflow matches outflow. 0.05” rain

1/6 MON LG -1.8’ Outflow exceeds inflow. 0.01” SWE

1/7 TUE LG -1.9’ Outflow exceeds inflow. Lake ice 80% melted.

1/8 WED LG -2.0’ Outflow exceeds inflow. 0.03” SWE. Lake nears target depth.

1/9 THU LG -2.2’ Outflow exceeds inflow. Siphons perform as calculated.

1/10 FRI LG -2.3’ Outflow exceeds inflow. Dry hydrant intake head exposed.

Scott, many many thanks for this and all previous reports, and Rob for collecting and publishing them on the website. It’s been great to have such detailed, ongoing information about how the drawdown has proceeded. I also really appreciate your having a found a 30-day period that helped to verify that the calculations were close to matching reality.

Based on our experience this year, so well recorded, I have some thoughts for next year about preventing the lake from rising so much above the 3′ drawdown level so frequently. I look forward to discussing them in due course.

Thanks, Harold

Scot,
Thank you for sharing this information with me I will pass it along to our contractor and my collogues. The board of fire commissioners has chosen a contractor to do the repairs on the dry hydrant. When the contractor notifies me of a start date I will share that with you.

Best Regards, Mike Lombardi Fire Commissioner

Scot & Skip,

The contractor for the Fire District plans to start the repair and extension project for the Truesdale lake dry hydrant tomorrow. If anyone has any questions feel free to contact me. (914) 588-8270.

Best Regards, Mike Lombardi Fire Commissioner

(after extension of dry hydrant)

Hi Mike,

I enjoyed meeting you at the boatyard and observing the final flow test.
Many thanks to you from all of us for the completed extension and nicely buried and deepened intake section.
And congratulations on your successful flow test today!

Scot

December 28, 2019
by rob
Comments Off on Drawdown: Report 11A

Drawdown: Report 11A

Greetings James,

This is ninth dry day of our break following all that pesky rain.

All your siphons are churning away nicely.

The lake ice continues to melt with rain arriving Sunday night, through Monday.

The lake level lowered at a rate of two inches per day during this dry spell (18” in nine days).

The 3” ice cap messed up the top of my tenths-graduated gauge, but today, the lake is 1.3 feet below the spillway and descending.

Enjoy your weekend!

Scot

Good news!
–James

December 23, 2019
by rob
Comments Off on Drawdown: Report 11

Drawdown: Report 11

Summary: This four-week report involved so many environmental changes that I had to wait to complete it until a break in the weather – the dry spell we’re experiencing – now in its third day. We received so much rain this month that the lake level rose 38 inches after receiving five inches of rain and Snow/Ice Water Equivalent (SWE), even with all siphons flowing much of that time.

When flowing, all three siphons draw nearly 12 million gallons of water out of the lake each day, so you can imagine how much water must flow in to continue increasing the lake level even while they are working.
The lake is now frozen, so we can observe what happens next when the water is pulled out from below the ice. If the ice doesn’t melt during the upcoming 40-degree days, it may start to cave in under its own weight through the air spaces up to the three-foot target depth. This may make access to the middle of the lake for ice skating and ice fishing rather challenging.

On the up side, if the ice cap over the siphons descends with the lake, it may help to prevent the whirlpools above the siphon intakes that form when target depth is near (see photo).

You have probably noticed that the lake rose to its maximum level of three inches above the spillway ramp elevation a few days ago, even with all the siphons flowing. Once again, this demonstrates that we’ll have no difficulty filling the lake back up in the spring as water flows from West Mountain heights down to our oasis.

The small 6” siphon continued flowing all by itself during the first two weeks of this reporting period. When the lake level rose from target depth to 2.8 feet below the spillway on December 1st (photo below), we requested that P&LC return to restart both 12″ siphons when the lake rose one more foot, which occurred ten days ago. P&LC restarted both 12″ siphons right on schedule – on the 10th & 11th of December – to keep up with the inflow. They will continue working until the 3-foot target depth can be reached for the fifth time.

While trees are without leaves, I’ll arrange a visit to Ridgefield Academy to take a photo of the lake from West Mountain and post it on NextDoor and in the next report so all can see that we live in a watershed valley.

	Rain Total	30 YR AVG	3 ft target depth achieved	Lake freezes completely
SEP	0.6″	4.5″	1st – Sunday 9/22
OCT	7.4″	4.6″	2nd – Monday 10/7
NOV	3.1″	4.4″	3rd – Tuesday 11/7	1st – Sunday 12/8, then melts
DEC	5.3″ (to date)	4.1″	4th – Friday 11/29	2nd – Friday 12/20 solid

When December ends in ten days, rain and SWE may match last year’s wet December that totaled 6.33 inches. Today, with all siphons flowing, the lake level is two inches below the spillway ramp and descending.

Daily Observations:

TUE 11/26 LG -2.5     Outflow exceeds inflow with all siphons flowing.
WED 11/27 LG -2.7′ Outflow exceeds inflow with all siphons flowing.
THU    11/28     LG -2.9’ Outflow exceeds inflow where the west 12″ siphon shuts down naturally.
FRI    11/29   LG -3.0’ Target Depth is achieved where the east 12″ siphon shuts down naturally.
SAT   11/30      LG -2.9’ Inflow exceeds outflow with only the 6″ siphon flowing.
SUN    12/1      LG -2.8’ Inflow matches outflow as Winter Storm Ezekiel approaches.
MON   12/2      LG -2.7’ 0.77″ rain where Inflow matches outflow.
TUE     12/3 LG -2.5’    0.20″ rain where Inflow exceeds outflow as coastal low pressure cell
moves in with steady light rain.
WED 12/4 LG -2.4’ Inflow exceeds outflow.
THU 12/5 LG -2.3’ Inflow exceeds outflow with salt added to each siphon frozen discharge.
FRI 12/6 LG -2.2’ Inflow exceeds outflow.
SAT 12/7 LG -2.2’ Outflow matches inflow.
SUN 12/8 LG -2.2’ Outflow matches inflow where 100% lake is frozen.
MON 12/9 LG -2.1’ 0.37″ rain where inflow exceeds outflow where lake ice completely melts.
TUE     12/10 LG -1.3’ 0.88″ rain where inflow greatly exceeds outflow with heavy rain.
P&LC restarts both 12″ siphons. (east shuts down)
WED 12/11 LG -1.3’   0.58″ rain where Inflow exceeds outflow after receiving 0.87” rain.
P&LC restarts east 12″ siphon.
THU 12/12 LG -1.3’ Outflow matches inflow with all siphons flowing well.
FRI 12/13 LG -1.3’ Outflow matches inflow with all siphons flowing.
SAT 12/14 LG -0.5’ 1.47″ heavy rain where inflow greatly exceeds outflow and all siphons flowing.
SUN 12/15 LG -0.2’ 0.7″ light rain where inflow exceeds outflow with all siphons flowing.
MON 12/16 LG + 0.1’ Level rises over spillway ramp for the first time this drawdown.
TUE 12/17 LG + 0.2’’ Inflow exceeds outflow with all siphons flowing.    WED 12/18 LG + 0.2’’ Inflow matches outflow with all siphons flowing.
THU 12/19 LG + 0.1’’ Outflow exceeds inflow with all siphons flowing.
FRI 12/20 LG 0.0’’ Lake level descends to spillway ramp height.
SAT 12/21 LG -0.1’’ Outflow exceeds inflow with all siphons flowing.

SUN 12/22 LG -0.2’’ Outflow exceeds inflow with all siphons flowing.

This report is set to launch upon the occurrence of Winter Solstice – at 2319 EST.

Happy Holidays to all,
Scot

Should we issue a warning to stay off the ice due to the risk of it collapsing as the drawdown continues?

–Lara

Hi Lara,

Good question and there are two aspects to consider here.

The first aspect is considering the effect of the drawdown with regard to the ice. The ice cannot support it’s own weight since it is flat and not shaped like an arch. The ice sheet will descend with the lake from the center out toward the perimeter. The air pockets and stress relieving ice breakage will occur in the perimeter areas where the exposed lakebed is already documented. The only risk to the resident is in navigating the broken ice and craters in order to get beyond the exposed lakebed perimeter on the way toward the center for good skating and ice fishing. So the risk for 90% of the lake will be the same as it has always been. Passing along this information may be better than issuing a warning to stay off the ice altogether, unless the board is concerned with potential liability.

The second aspect is the classic monitoring and reporting of ice conditions so residents can make their own decisions as well as assume the risk for skating or ice fishing.

Meghan Crystal has posted a question about ice conditions on NextDoor. So regarding your question above, I’ll answer with a post about today’s conditions only. Please let me know if you want to post a caution regarding the future or if you want me to.

Scot

November 26, 2019
by rob
Comments Off on Drawdown: Report 10

Drawdown: Report 10

Summary: The 6” siphon continued flowing during this last two week period and we requested that P&LC restart both 12″ siphons.
On Wednesday 11/20, a Lake Planning Group Meeting was held with John Bergstrom, Robert & Susan Brown, Rob Cummings, Sue Enos, Scot Evans, Lara Gorton, Stephen Macaluso, and Harold Ossher attending.

James Gorman and crew of P&LC restarted both 12” siphons Friday 11/22 at 10:30 am following the one inch of rain we received two days earlier, where the Lake Gauge started at -2.8 feet and steadily rose 8 inches to -2.1 feet.

With another inch of rain received yesterday, all siphons are flowing and we are currently -2.5 feet below the spillway.

Daily Observations:

TUE 11/12 LG -2.8’     Winter Storm Caleb arrives bringing rain and snow mix totaling only 0.05” liquid precipitation. Lake level rises 0.7”
WED 11/13 LG -2.7′ Inflow exceeds outflow with 6” siphon continuing to flow at 125 CFM.
THU    11/14     LG -2.7’ Inflow matches outflow
FRI    11/15   LG -2.7’ Inflow matches outflow
SAT   11/16      LG -2.7’ Inflow matches outflow
SUN    11/17      LG -2.7’ Inflow matches outflow
MON   11/18      LG -2.7’ Inflow matches outflow
TUE     11/19     LG -2.5’ Inflow exceeds outflow as coastal low pressure cell moves in with steady light rain.
WED 11/20 LG -2.3’ Inflow exceeds outflow after receiving 0.87” rain. Lake Planning Group Meeting held.
THU 11/21 LG -2.2’ Inflow exceeds outflow.
FRI 11/22 LG -2.1’ Lake is a foot higher above target depth as P&LC arrives to restart both 12” siphons. All flowing at 1,100 CFM.
SAT 11/23 LG -2.4’ Outflow exceeds inflow. Winter storm is approaching from the southwest.
SUN 11/24 LG -2.5’ Storm brings another inch of rainfall today and all siphons are flowing.
MON 11/25 LG -2.4’ Inflow exceeds outflow.
Scot

Thanks, Scot, and thanks to James for the timely restart of the large siphons.
Happy Thanksgiving, everyone!
– Harold

November 18, 2019
by rob
Comments Off on Drawdown: Aerial Survey Lake Perimeter

Drawdown: Aerial Survey Lake Perimeter

A friend lent me his drone for an aerial survey of the lake as it is now during the drawdown. I have posted below some of the photos from November 15 when the lake was half frozen on the surface.

The rest (many more than shown below) are in this album online: https://www.smugmug.com/gallery/n-ND9bvm/

DCIM\101MEDIA\DJI_0014.JPG
DCIM\101MEDIA\DJI_0019.JPG
DCIM\101MEDIA\DJI_0031.JPG
DCIM\101MEDIA\DJI_0037.JPG
DCIM\101MEDIA\DJI_0042.JPG
DCIM\101MEDIA\DJI_0044.JPG
DCIM\101MEDIA\DJI_0053.JPG
DCIM\101MEDIA\DJI_0065.JPG
DCIM\101MEDIA\DJI_0075.JPG
DCIM\101MEDIA\DJI_0089.JPG
DCIM\101MEDIA\DJI_0097.JPG
DCIM\101MEDIA\DJI_0099.JPG
DCIM\101MEDIA\DJI_0108.JPG
DCIM\101MEDIA\DJI_0123.JPG
DCIM\101MEDIA\DJI_0126.JPG
DCIM\101MEDIA\DJI_0132.JPG
DCIM\101MEDIA\DJI_0137.JPG
DCIM\101MEDIA\DJI_0149.JPG

November 13, 2019
by rob
Comments Off on Drawdown: Report 9

Drawdown: Report 9

Summary: Both 12″ siphons shut down: the west 12” on Tuesday night 11/5/19 and the east 12” on Wednesday night 11/6/19. The 6” siphon was the only one flowing most of this week and it was able maintain the lake level following 0.3″ rainfall with a 2 ½” lake level rise. Lake Gauge started at -3.0′ target depth and ended the week rising to -2.8′.

Two 12″ siphon pipes dry (right) and 6″ siphon pipe energized and flowing (left).

Hoyt Street lake gauge showing around 2’10” below spillway height.

The intake head of the west siphon is 9” below target depth and the east siphon intake head is 17” below target depth. Both developed widening whirlpools above the intakes and this is likely what shut them down. We need to figure out something that eliminates the whirlpools over the intakes. Internal baffles and external fins are two ideas to reduce or eliminate the whirlpools above the intake heads. External fins in second diagram would be easier to construct and less restrictive to the flow. Experiment with this design first.

External fins with the fin “trailing edges” leading out from the siphon intake head.Experimentation will determine minimum number of fins necessary to eliminate a whirlpool – i.e. eight or fewer fins.
Daily Observations:

TUE 11/05 LG -2.9’ All siphons operating with west whirlpool widening. West siphon shuts down that night.
WED 11/06 LG -3.0′ Target depth achieved once again after the October 10th departure from our last target depth achieved.
THU 11/07 LG -3.0’ Both 12″ siphons have shut down. Scot took measurements of these siphons to provide to Cliff Munz, who is working on a large construction project and cannot convert the siphon design to CAD at this time.

FRI    11/08   LG -2.9’ LLR begins with 0.3″ rainfall. 6″ siphon operating at 125 CFM.
SAT   11/09     LG -2.8’ Inflow continues to exceed outflow
SUN    11/10    LG -2.8’ Outflow matches inflow with 6″ siphon flowing

MON 11/11 LG -2.8’ As above. Sue Enos schedules Lake Planning Group Meeting for 11/20/19.
Scot

Email from Michael Lombardi, South Salem Fire District Commissioner, regarding the dry well on the north end of Lake Truesdale near Indian Lane and the Dam.

Dear Skip,

The board of fire commissioners is weighing options to repair and extend the dry hydrant pipe in Lake Truesdale. We have the following questions.1. Will the lake draining program be an annual process or is this the only year it will be done. 2. Is the lake going to be drawn down further. 3. When will the lake be refilled.

Thank you in advance for your assistance feel free to contact me.

Michael J Lombardi Fire Commissioner (914) 588-8270

Thank you for contacting us Michael. We will be planning to do the lake drawdown annually as a way to better control weed growth and overall health of the lake.

The drawdown is at the expected level at this time with only one smaller siphon running to maintain the target depth with expected normal rainfall.
The drawdown will last until February 1, 2020 – that’s when we will turn off the maintenance pipe. This is the smaller 6″ pipe which we will use to try to keep the lake level 2.5 – 3 feet below the spillway level.

After then the lake will fill up with winter snowmelt and spring rain. We anticipate it will be back to regular height by May 1, 2020 and likely well before then.

More information on the drawdown is published on the Truesdale Lake web site – http://truesdalelake.com

Thanks for your support,
Skip Jahn

November 6, 2019
by rob
Comments Off on Drawdown: Report 8

Drawdown: Report 8

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.

http://cloud.cocorahs.org/wys/2018-2019/NY/NY-WC-22-wys-2018-2019.xls

http://cloud.cocorahs.org/wys/StationWysCharts.html?station=NY-WC-22&wateryear=2019

http://cloud.cocorahs.org/wys/2018-2019/NY/NY-WC-22-wys-2018-2019.html

–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

October 29, 2019
by rob
Comments Off on Drawdown: Report 7

Drawdown: Report 7

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.

Today (Oct 29, 2019), the lake gauge is 2.0 feet below the spillway deck.

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.

Newly exposed islands off of Gilbert Street houses north of the beach property.

Pirate Island (southernmost island) is shown here as Pirate Peninsula with stone wall connecting the island to the mainland.

Dormant Siphons during the September Drought.

Indian/Gilbert boatyard with dry hydrant that Skip Jahn identified and notified the fire department. They have not yet responded to lengthen the uptake head.

East side of South area and Pirate Island.

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

View of wildlife exploring and hunting on the newly exposed “Galapagos Islands” off of Gilbert Street.

October 21, 2019
by rob
Comments Off on Drawdown: Report 6

Drawdown: Report 6

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