Truesdale Lake  

South Salem, New York

Lake Drawdown


Related past article links:

2024 Update

We have begun the drawdown in November. See drawdown related posts on this site for details.

2023 Update

We did a drawdown for the 2022-23 winter season, but the winter was so mild it was not as effective. The warm temperatures caused what would normally be snow storms to be rain instead and the lake kept filling back up. The hard freeze never came during the time the shorelines were exposed. This means the main effect sought from the drawdown was not achieved.

2022 Update

We did not do a drawdown for the 2021-2022 winter season. On the advice of Pond & Lake Connection they recommend an every other year strategy for drawdown. We plan to draw the lake down again during winter 2022-2023.

2021 Update

The 2020-2021 drawdown was mostly successful. We did not achieve a consistently low waterline for several months due to rain events filling the lake back up several times and the freeze coming later than normal. But the shorelines were exposed and the treatment levels for the 2021 season were below normal.

2020 Update

The 2019-2020 drawdown was a success in a number of ways:

  • It resulted in the reduction of submersed weed growth in the shallower (<3ft) sections of the lake (the areas exposed to the air and compacted by freezing and drying) in the peak early weed growth season from April-May.
  • It reduced the volume of lake treatment herbicide used in the early part of the spring 2020 season by approximately 50%.
  • Riparian homeowners were able to clean up areas around waterfronts and docks and do minor repairs to existing seawalls and docks.
  • Debris and garbage was revealed and removed in many areas of the lake where it had drifted or settled.

We plan to do the drawdown again in the 2020-21 season starting mid-October.

The reason to start mid-October is because of the lake inflow-outflow calculations tell us that in order to get to the goal depth (4 feet below spillway height) by December 1st we need approximately six weeks.

This gives us a buffer of around two weeks before the hard freeze of the lake in case we have an unusual amount of rain. It is hard to predict the weather — both the temperature and precipitation.

We try to balance getting the drawdown accomplished vs. having the lake easily available for recreational boating use for the maximum amount of time. Bottom line is we have to have a start point or we will never see the end result we are shooting for. And the long-term benefits will be reduced.

Depending on your launch point, the lake can still be accessed — but you might have to take an alternate path. For example, the entirety of the south end of the lake will be landlocked. Certain bays and areas will also have 50-100′ of mud between their docks and the water. Other steeper or more rocky shorelines will be able to launch a boat during the drawdown. But once the lake freezes it will still be possible to skate, ski, and walk on the lake.

The siphons will be stopped in early February 2021 at which point the lake will fill up from snowmelt and precipitation over time. Average time for a complete refill is 3 weeks. The spring has the most precipitation of any season. As an example, last year the lake refilled in 3 days after shutting down the spigots.

2019 Update

Why drawdown the lake?

The main benefit of a drawdown is weed control: the exposed lake bottom will compact, desiccate over time, and freeze, thus killing off the weed roots and tubers.

Drawdown will also compact the shoreline soil reducing the “muck” in some places — and increase the usable depth of the lake.

A drawdown will also allow homeowners on the lakefront to:

  • clean up any debris, branches, leaves, or trash that may become visible once the lake bottom is exposed,
  • cut invasive phragmites on the waters edge,
  • make repairs to walls and docks (in kind repairs generally don’t need permits, but check with town wetland consultant before undertaking anything big to avoid potential fines),
  • begin new construction projects (seawall, dock, others?)
    • All new docks on the lake require DOCK COMMITTEE APRROVAL,
    • plus all projects in the wetland buffer require PROPER TOWN WETLAND and PROPER TOWN BUILDING PERMITS).
Truesdale Lake Watershed:
~2380 acres,  Lake size ~83 acres = 23:1 ratio.
Truesdale Lake Watershed (~2380 acres) 

Diagram of siphons

[Historic Information below from first drawdown attempt]


Greetings! This is to let you know that plans are in place for Pond and Lake Connection (the company that has managed Truesdale Lake weed and algae control for the past two years) to commence work on the Truesdale Lake drawdown for 2018. They will install the necessary pipes and pumps in early October. The actual drawdown will take place between October 15 – December 1, 2018. It is estimated that by the time that the drawdown is complete, the lake will be 2 – 3 feet lower than its usual winter height. Riparian homeowners will have a chance to rake out the areas in front of their homes, or to work on stone walls or docks.

Click to view some Frequently Asked Questions about our drawdown.

Click for more information about drawdowns from the lake manager handbook.

Presentation on how the Truesdale Lake Planning Group came to recommend drawdown.

Once the drawdown is in place, the lake will be kept at that height until February 1, 2019. This will provide time for the lake bottom to compress, and also for (hopefully) cold winter weather to freeze exposed weeds.

Beginning on or about February 1, 2019, the drawdown will end and the lake will begin to refill. Given historical records, it is anticipated that the lake will be back to its usual height by about May 1, 2019.

Obviously, the exact timing of the drawdown and all of these plans will be weather dependent.

We will provide updates about the Truesdale Lake Drawdown from time to time as there is information to report via Next Door, the Truesdale Lake email list and posting to

Lake Drawdown Do’s and Don’ts


  • Remove or untether your docks if necessary before the drawdown begins on October 15
  • Clean up the area exposed by the lower water level and remove branches, fallen trees or other debris


  • An Excavation/Fill in Navigable Waters permit is required from the NYS DEC for any excavation or fill below Mean High Water (MHW)
  • The MWH is the level of the lake at its highest in the summer – not the level where the water will be after it is drawn down
  • The DEC can impose fines as high as $1500/day on any work done in the lake without a permit.