Monday May 27, 2019

Response from the TSW Regarding Our Water Levels

After a significant amount of pressure was put on the Trent-Severn Waterway (TSW) regarding the water levels this year (including a letter from Halls Hawk Lakes Property Owners Association), Parks Canada has responded with an explanation about why we are experiencing these conditions and some steps they are taking in an effort to recover some water.

2010 Water Level Conditions Trent-Severn Waterway, National Historic Site of Canada Haliburton Area

Please CLICK HERE to view the original letter from Parks Canada.

Water levels in some of the Haliburton Area lakes have been unusually low this spring. This has resulted in number of inquiries to Parks Canada, which help the organization understand the various perspectives and concerns of water stakeholders. It is not Parks Canada’s intent to cause undo disruption to the residents and cottagers of the Haliburton Area – your messages have been received. To assist in understanding the situation, Parks Canada has prepared this report, providing an overview of various factors which have contributed to current levels.

The winter of 2010 started off with snowfall accumulation above what would be experienced in an average year. Through the end of February, snow accumulations were very close to average. However, the “water content” in the snowpack, as an important indicator of reservoir fill potential, was very close to or above average.

At beginning of March the water content contained within the snowpack was still near average however the snowpack began to diminish very rapidly. Lower than average precipitation in March and April allowed the existing snowpack to dissipate without generating any significant runoff.


Throughout the winter, Parks Canada officials were monitoring the situation closely. Up to the end of February, with the prospect of average spring rain, the indicators did not cause significant concern about the ability to fill the reservoir lakes, nor did they dictate a departure from the standard operating regime. March and April 2010 saw metrological conditions that were profoundly different from norm. After having been drawn down in the fall, reservoir lakes are typically re-filled, with the runoff from the melting snowpack in March and the spring rains in April. Unfortunately, this year there was no typical spring freshet and the early spring rains that are normally counted upon were largely absent. Data from March/April follow:

  • Recorded snow at the Haliburton Environment Canada weather station during the month of March 2010
    was 3.6 cm (average snow received in March: 33.2 cm);
  • Last snow recorded “on the ground” at the Haliburton Environment Canada weather station was on March
    16, 2010 (in the 3 years previous, snow was recorded on the ground into mid-April); and
  • Recorded rainfall at the Haliburton Environment Canada weather station during the months of March and
    April 2010 was 47.4 mm (average rainfall for those months is 147 mm).


Conditions in the winter and spring of 2010, outlined above, made filling the reservoir lakes, particularly on the Gull River system, very difficult. Parks Canada officials recognized the unusual conditions that were occurring early in March and moved to replace the stoplogs as quickly as possible. It had little effect because there was neither a freshet caused by the melting snowpack nor the spring rains to catch. As a result, there are currently a number of lakes in the Haliburton Area that are at or near historic (recorded) low levels, still weeks from the summer season. It is worth pointing out that these meteorological conditions and low water level concerns are not localized to just the Trent River watershed. Lake Ontario’s water level was, up until recently, 18 inches below where it was last year and the Saint Lawrence River at the Port of Montreal is 6 feet below average. This effect is causing concern amongst Seaway authorities over the effect on Great Lakes shipping.

The summer forecast of hot and dry conditions coupled with already low reservoir lakes is causing understandable concern amongst lake residents. To this end, Parks Canada officials have been positioning the watershed to best meet the anticipated demand for water. As such:

  • The Kawartha Lakes are being overfilled as much as possible in order to minimize the likelihood that water
    from the reservoirs will be required in the near term;
  • Parks Canada officials will continue to use the historic drawdown methodology of the reservoir lakes. Officials are cognizant that there is currently an imbalance in the system because reservoir lakes filled irregularly. Officials will be balancing the reservoir situation and utilizing water first from lakes that are at a higher storage percentage;
  • Water will be conserved as much as possible throughout the season. Dams will be tightened and consideration will be given to carrying water levels on the navigable corridor at the lower end of the navigation ranges;
  • The installation of additional automatic gauge stations, procured under Canada’s Economic Action Plan, have been accelerated so that Parks Canada officials have better, real-time situational awareness of water levels in the reservoir lakes. This data will be made available to the public as soon as the installations are up and operating via the Trent-Severn Waterway National Historic Site of Canada water levels web site available at:
  • A program to replace old stoplogs, funded by Canada’s Economic Action Plan, is making a number of dams tighter thereby conserving any water that had been leaking.

For more information:

Jack Alexander
Director of Canal Operations
Trent-Severn Waterway
(705) 750-4900
Dave Ness
Water Control Engineer
Trent-Severn Waterway
(705) 750-4900