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Trent-Severn Waterway

The Trent-Severn Waterway uses a network of real-time and manual monitoring stations to measure water levels, flows and rainfall throughout the watershed. The primary role of the watershed-monitoring network is to provide comprehensive and up-to-date information to the water management team for decision making on water control.  During flood events this system is critical to providing instantaneous information about current conditions.  This information is now available to the public through this interactive website. 

How to use the site:
Step One:
In order to find the water level on a particular lake you must first select the watershed area on the map where the lake is.  Using the interactive image you must select one of the following regions:

  1. Severn River Watershed
  2. Gull River Watershed
  3. Burnt River Watershed
  4. Nogies, Mississagua, Eels, and Jack Watersheds
  5. Kawartha Lakes
  6. Rice Lake and Trent River


Please note: The Crowe Valley Conservation Authority operates the dams within the Crowe River Watershed.  Information regarding their operations can be found on their website which is:

Step Two:
Once you have selected a watershed region by clicking on it, another image will appear showing the lakes and rivers within that watershed region.  By moving your cursor over the red dot on the image, the lake name will appear.  Click on the dot to see the water levels for that lake. You must accept the disclaimer prior to every water level graph.  Information explaining the content of the graph will appear as you move around the legend. 

How to read graphs – Legend Items:

Daily Water Levels – These are the actual water levels observed by Trent-Severn Waterway staff.  The water levels are gathered manually by staff reading the gauges or by automated gauging stations.  Data from the automated gauging stations is updated more frequently than manual stations because of the time needed to travel to a manual site.  The data shown is for the current calendar year. 

Historic High Water Levels – The Trent-Severn Waterway is continuously analysing water level data for all lakes in the system.  This data is archived and has resulted in a vast collection of information about the fluctuations of water levels throughout the year.  The Historic High Water level line represents the highest recorded level the lake has experienced in the past 25 years.  This does not mean that the line will not be exceeded, but the likelihood is relatively low.  Extremely wet conditions may result in the historic observations being exceeded.  

Historic Low Water Levels – The Trent-Severn Waterway is continuously analysing water level data for all lakes in the system.  This data is archived and has resulted in a vast collection of information about the fluctuations of water levels throughout the year.  The Historic High Water level line represents the lowest recorded level the lake has experienced in the past 25 years.  This does not mean that the line will not be exceeded, but the likelihood is relatively low.  Extremely dry conditions may result in the historic observations being exceeded. 

Navigation Range – Each of the lakes along the navigation channel of the Trent-Severn Waterway, except Lake Simcoe, have upper and lower navigation limits. These limits show the upper and lower water levels between which navigation is maintained.  Normally, excess water is tolerated on many lakes and rivers within the system because slightly more water on the system will not impact the navigation draught.  Retaining extra water on the lakes within the system will also result in less burden on the reservoir lakes when dry conditions do arise.

Rule Curve – A set of target water levels that vary over the year to accommodate normal hydrologic patterns and water management priorities.  Deviations from the Rule Curve may unavoidably occur during wet and dry conditions, and they may be permitted if the situation benefits the majority of users in the system.  The existing Rule Curve has been in place for over 80 years and has been studied extensively to determine if a better management regime could be found.

Summer Water Level – A target water level to be maintained during the summer of the year.  The operation of Six Mile Lake is slightly different than other bodies of water within the Trent-Severn Waterway because it is not on the navigation route.  For this reason, a target level is utilized rather than a navigation range.

Watershed Descriptions:

The Severn River Watershed

The Severn River watershed lies immediately west of the Trent River basin and drains west into Georgian Bay. This 6,160 square kilometre drainage area has three major components:

1.  The Lake Simcoe and Lake Couchiching basin including the Talbot River.
2.  The Black River watershed that feeds into the Severn River downstream of Lake Couchiching.
3.  The lakes and channels of the Severn River below Washago, including Sparrow Lake, Six Mile Lake, and Gloucester Pool.

Most of the drainage area for the Lake Simcoe-Couchiching basin is in rolling farmland and deeper soils characteristic of the southern area. As a result, water run-off is slow and evaporation losses from both land and lake surfaces are high.  The Black River watershed, located in the thin soils and rock of the Precambrian Shield, is virtually unregulated and produces rapid run-off of precipitation while evaporation losses are lower.  Consequently, even though the watershed is less than half the area of the Simcoe-Couchiching basin, its long-term average flow is comparable. The Black River also has high peak flows during the spring. Both the Black River and the Severn River are constrained by numerous constrictions, which are prone to increased water levels in the river and upstream flooding during high flows.  The Black River remains the main cause of flooding on the Severn River because of the potential to generate extremely high water levels.

The Gull River Watershed

The Gull River watershed is at the very top of the Trent River basin and lies between the Black River watershed to the west and the Burnt River watershed to the east.   With a drainage area of approximately 1350 square kilometers, the Gull River makes up approximately 10% of the total drainage area of the Trent River.  The Trent-Severn Waterway operates 21 dams within the Gull River watershed.  The lakes that are controlled by the various dams on the Gull River are typically deep, cold-water lakes that support a rich lake trout fishery.  In addition, the surface area of the lakes within the Gull River are relatively large when compared to other lakes in the Burnt River watershed.  With their large capacities, the lakes within the Gull River system can more easily cope with high inflows when compared to the lakes within neighbouring watersheds.  As a result of the large water volume of the Gull River system, the flows generated during the spring are typically less than half the flows on the Burnt River, which is nearly the same drainage area.  The outlet of the Gull River is in the town of Coboconk where the river enters Balsam Lake.

The Burnt River Watershed

The Burnt River watershed is near the top of the Trent River basin and lies between the Gull River to the west and the Nogies Creek, Mississagua River, and Eels Creek watersheds to the south, southeast, and east respectively.  While the drainage area of the Burnt River is only slightly smaller than that of the Gull River, at approximately 1300 square kilometres, the Burnt River is capable of generating extremely high spring flows.  The Trent-Severn Waterway operates 13 dams within the Burnt River watershed.  The majority of the lakes within the Burnt River are relatively small in terms of both their storage capacities and their surface areas.  This is the main reason why the Burnt River is capable of generating such high flows.  With a finite amount of storage in the lakes in the headwaters of the Burnt River, the system is incapable of absorbing extreme melt water and/or precipitation.  Once local inflow has filled the lakes in the headwaters of the Burnt River, any additional water moves to the lower Burnt River, downstream of Kinmount, where the majority of the flooding occurs.  The outlet of the Burnt River flows into Cameron Lake, where the flows from Balsam Lake unite at Rosedale, and head downstream to the town of Fenelon Falls.

The Nogies, Mississagua, Eels, and Jack Creek Watersheds

Some of the smaller, but no less important, tributaries of the Kawartha Lakes are the Nogies Creek, Mississagua River, Eels Creek, and Jack Creek watersheds.  The Nogies Creek watershed contains only one reservoir operated by the Trent-Severn Waterway, that of Crystal Lake.  At the headwaters of the Nogies Creek watershed, Crystal Lake is fed by several small tributaries which help to fill the lake during dry springs.  Downstream of Crystal Lake, Nogies Creek (formally know as Harvey Brook) flows through both Bass Lake and Big Marsh Lake before entering Pigeon Lake at its north end.

The Mississagua River watershed is a significant tributary of the Kawartha Lakes and lies between the Nogies Creek watershed to the west and the Eels Creek watershed to the east.  With Anstruther Lake flowing into it, Mississagua Lake contributes a substantial volume of water to the Kawartha Lakes.  Nearly 15% of the water retained in the reservoirs come from Anstruther Lake and Mississagua Lake.

The Eels Creek and Jack Creek watersheds have very similar characteristics.  With each having a single reservoir within their headwaters, the watercourses behave very much the same throughout the year.  The primary difference between the two is the size of Eels Creek compared to Jack Creek.  The Eels Creek watershed has both a large reservoir in its headwater and a large catchment area which contributes to its surface water runoff.  For these reasons the Eels Creek watershed will generally generate higher flows than Jack Creek throughout the spring.

The Kawartha Lakes

The Kawartha Lakes includes all lakes upstream of the Otonabee River but downstream of the Haliburton reservoir system.  The Kawartha Lakes have 6 major tributaries which help to maintain the 6’ navigation draught on this portion of the canal throughout the summer months.  The most westerly of the Kawartha Lakes is Balsam Lake, the top of the navigable portion of the Trent-Severn Waterway.  From Balsam Lake boaters can either go west to the Kirkfield Lift Lock and downstream to Canal Lake or go east to Rosedale and downstream to Cameron Lake at Lock 35.  Balsam Lake is also where the largest tributary of the Kawartha Lakes, the Gull River, enters the system.  As mentioned, downstream of Balsam Lake to the east is Cameron Lake and this is where the second largest tributary, the Burnt River, enters the Kawartha Lakes.  Continuing east downstream through Fenelon Falls is Sturgeon Lake.  Sturgeon Lake is significant because of the ability for boaters to either go upstream to Cameron Lake or upstream to Lindsay and Lake Scugog.  Continuing downstream through the town of Bobcaygeon the flow of the Kawartha Lakes enters the tri-lakes.  Pigeon Lake, Buckhorn Lake, and Chemong Lake are commonly referred to as the tri-lakes because despite having three names they are all one body of water allowing boaters to visit all three lakes.  Pigeon Lake is also where the outlet of Nogies Creek enters the Kawartha Lakes.  Downstream of the town of Buckhorn is Lower Buckhorn Lake, commonly referred to as Deer Bay because the bay makes up such a large percentage of the lake.  Continuing east to the smallest lake in the Kawartha Lakes, Lovesick Lake was not originally intended to exist at all.  The dam at the outlet of Lovesick Lake at Burleigh Falls was actually constructed to flood Lovesick Lake to the same elevation as Lower Buckhorn Lake making the two lakes one body of water.

Rice Lake and Trent River

Rice Lake allows through navigation between Hastings (at its outlet) all the way up the Otonabee River to Peterborough.  While Rice Lake remains a large body of water within the Trent River basin, it is not drawn down during the winter to mitigate against flooding.  Rice Lake typically enjoys moderate water level fluctuations throughout the summer but during extreme spring conditions can experience rather severe flooding.  Because of narrow river sections on approach to Hastings, the volume of water from the Otonabee River is naturally held back, flooding Rice Lake.  Despite opening the dam completely Rice Lake will still experience flooding because of this constriction.  Similar conditions are experienced along the Trent River downstream of Hastings at Seymour Lake, Percy Reach, and Frankford.  The Crowe River joins the main branch of the Trent River just downstream of Healey Falls at Crowe Bay.  Several other small tributaries join the river between Crowe Bay and Trenton where the mouth of the Trent River enters the Bay of Quinte.