TSW Update & Forecast – June 15/21

In spite of some locally significant rainfall events the extreme drought conditions continue across most of the Trent River basin including in the reservoir areas. Many of the largest reservoirs failed to reach their full level this spring and now the drawdown has begun to offset the high evaporation rates and lack of rainfall over the Kawartha lakes. Several reservoirs are projected to see a drop of more than 20cms over the next two weeks. In most cases the more extreme drawdown rates will be on the reservoirs that have been closest to their normal seasonal levels.

The drawdown forecast will be produced weekly by TSW and always forecasts the situation for a two-week period. CEWF will post the weekly forecast as soon as we receive it.

The current situation is very serious and we will need well above normal monthly rainfall totals to recover from what are already seasonally low water levels in most cases

Readers are encouraged to follow the plot of reservoir levels on the TSW website (link on upper right) and the local weather patterns for Haliburton and Peterborough (link on the lower left).

To view the TSW two-week drawdown forecast – click here

TSW Water Management Update: (to view TSW website – click here)


Rainfall amounts for March-May have contributed to 40-55 % less precipitation compared to the long term mean value for spring season. The month of May contributed to values that are less than 50-75 mm than the long-term mean.  The 5-day forecast suggests 15-25 mm of rain and above 20 C day time air temperatures.  Most of the rainfall forecasted is associated with thunderstorms and could be highly variable from one location to another.


The spring of 2021 has presented a unique set of challenges for the water management program of the Waterway.  The early melt and exceedingly dry conditions resulted in the minimal flows experienced since early April until present across the system and the low levels in all flow-through lakes. The dry conditions resulted in additional strain on some of the Haliburton Reservoirs more than others.  Every effort is made to ensure that water management decisions are carefully considered, acknowledging Parks Canada’s responsibility to balance the needs of all users in the system.

The Trent Severn Water Management team is active on the daily basis, and the changing conditions will be closely monitored. Any watershed condition updates will be released by your Conservation Authority or local Ontario Ministry of Natural Resources district.

Haliburton and Northern Areas

Most lakes are below long term average water levels. The Gull River reservoirs are 85% full. Burnt River reservoirs are 90% full. The Central Reservoirs are 91% full. The drawdown has commenced and the rate of drop will be largely dependent on the rainfall received.