Drag and Spruce Lakes are reservoir lakes, managed as part of the overall Trent-Severn Waterway System. The Coalition For Equitable Water Flow (CEWF) is an organization through which our interests are represented. DSLPOA has been a long standing member of the Coalition for Equitable Water Flow (CEWF) and we currently have a seat on the CEWF Executive Committee.
CEWF is a volunteer organization that was formed in August 2006. It's goal is to represent the interests of the more than 30,000 Ontario taxpayers who own residential shoreline property on 55 lakes that feed all the way down into the Trent Canal, the water levels of which are controlled by the Trent Severn Waterway.
Membership in the Coalition is open to Lake Associations, or equivalent organizations, in the Sector. The operations of CEWF are handled by an Executive Committee which represents its membership with TSW, local municipalities, and both the provincial and federal governments, where appropriate. The municipalities CEWF works with include the townships of Algonquin Highlands, Dysart et al, Highlands East and Minden Hills in Haliburton County; and both North Kawartha and Trent Lakes in Peterborough County.
Primer on Drag and Spruce Lake Water Management
Drag Lake, Spruce Lake and Outlet Bay are headwaters for the Burnt River, and part of the Trent-Severn Waterway (TSW) reservoir lakes system. The water outflow from the lakes, hence the lake water level, is dam controlled. The north and south dams at the west end of Outlet Bay are under the authority of Parks Canada TSW staff. See a detailed description of the overall TSW water management program here.
View from the top of the Drag Lake dam (June 21, 2010) at near full fill condition
The water level of the lakes are adjusted via the manual insertion and extraction of a series of one foot square logs.
View from the bottom of the dam, with all (7) logs in place
There is also a privately owned and operated hydroelectric power generating station located at the dam site. When water is being released by Parks Canada for its water management needs, the outflow is typically directed to power generation, as long as the flow requirements set by Parks Canada can be met. The power company is not charged for the use of the water under the current contract.
View from the top of the hydro dam with the water flow pipe seen to the right
View of power generating station below dam, showing water inflow pipe, and the first electric utility pole used for transmitting generated power to the grid
Stated simply, the annual water management cycle is as follows:
- Fill up the lake in the spring from snow melt and rain,
- Draw down the lake through the summer to sustain minimum navigation levels on the TSW canal (as part of the overall reservoir lakes
system), - Then establish the winter set lake level in the fall with the objective of leaving adequate reserve water storage capability to avoid downstream spring flooding.
Other factors, notably fisheries, also come into play when managing the timing. The various lakes in the TSW reservoir system have differing dam infrastructures, and as such see different annual lake level fluctuations. For our lakes:
- Total available draw down level = 1.74m (~ 6 feet). In a typical year, only one-half of this is utilized,
- The available draw down equates to water storage volume ~ 20 billion liters,
- Following is a graph showing the annual water levels for Drag Lake ( = measured lake level in meters above the dam sill):
- See a graph showing the annual water of our lakes, measured lake level in meters above the dam sill, here.
Looking at long term historical averages, our lake are at its target ‘full’ level through the month of May, and is drawn down approximately 1.1m (~ 3.5 ft) to its minimum level in the month of October. The target ‘full’ level is actually only 95% of the maximum available. This percentage has been established through practical experience, and the typical minimum we experience is more than 2 feet higher than is available to be drawn down. Throughout the years, there are wide variations from the averages. To illustrate, here are the historical measured extremes:
- Maximum is 2.5 feet above the ‘full’ level (May 1914),
- Minimum is 7 feet below the ‘full’ level (March 1945),
- It is notable that while our lakes typically goes through an annual 3.5 feet swing in lake levels, there is a 9.5 feet difference between the historical maximum and minimum.