Fairy Lake Annual General Meeting Dave Macpherson Water Management Technical Specialist Parry Sound District Ministry of Natural Resources

Parry Sound District Water Management The Team Andy Heerschap District Manager Trevor Griffin Area Supervisor, Bracebridge Office Amanda Vincent Area Technician Ken Molyneaux Area Technician Dave Macpherson Water Management Technical Specialist Steve Taylor Water Resources Coordinator

Summary  The Ministry of Natural Resources has been actively managing nearly 40 (38) dams in the Parry Sound District for over 40 years.  In total The Parry Sound District Ministry of Natural Resources owns over 70 (76) dams  The experience gained over this period is reflected today in the rule curves that the present staff use to make daily management decisions.  Dam Operating Manuals and Water Management Plans contain detailed information that is used to help balance the needs of the many stakeholders that rely on the reservoirs.  On a daily basis staff check and record water levels on 16 Lakes, discharge in 12 rivers, precipitation at 6 locations and the weather forecast from three sources. This information is used to decide how to manage individual dams to achieve the goals described in Water Management plans

Dams  In the Parry Sound District Dams range from large multiple opening structures that require frequent visits to small structures that to the untrained eye may not be recognizable as a water control structure.

Water Levels  Water levels are managed by removing or replacing stop logs into the dam.  By adjusting the size and elevation of the dam opening we adjust the amount of water moving through the structure.  If the reservoir level needs to go up we make the opening smaller so there is less water leaving the reservoir then entering it. If the level needs to go down we make the opening bigger so more water is going out than coming into the reservoir

How do we know what to do?  Water Levels in Parry Sound District Reservoirs are directed using a rule curve approach.  The rule curve guides operators so we can adjust lake levels to meet the needs of different stakeholders at different times of year Recreation & Navigation Ecology & Flood Control Hydro Production Climate & Hydro Flood Control Climate & Ecology

Water Management Plans  The need for Water Management Plans originated from Hydro deregulation and is administered under the Lakes and Rivers Improvement Act  The Muskoka River Watershed is managed following the direction of the Muskoka River Water Management Plan.  The plan was developed to balance the needs of the many stakeholders on the system and is a valuable tool for Water Control Staff.  A similar but less formalized approach is used for reservoirs outside the Muskoka River Watershed  A Water Management Plan involves extensive research and consultation to establish priorities for water level management, this way operations staff can focus on managing the lake to a level that is most appropriate.  The MRWMP uses an adaptive management approach. The performance of the plan is evaluated midway through and at the end of the term and changes can be made to address needs of stakeholders if this can be done without compromising another objective.

Longer Period of higher water levels provides a better opportunity for wetlands and other seasonally inundated areas to develop & provided sustained discharge during the Walleye Spawning and incubation period. Reduced winter drawdown helps minimize impacts on lake trout eggs that develop over winter Declining summer water level provides fresh water during a period of typically dry weather Increased fall drawdown reduces difference between fall and winter level & fish to spawn at lower elevations Revised Target Operating Level

Meeting the Objectives  The volume of water moving through the system can vary greatly depending on climate conditions.  Periods of dry of wet weather can result in less or more water in the system  Dams must be adjusted accordingly so water levels can be maintained as close to the target operating level as possible.  On a daily basis water control staff review and document watershed conditions to plan operations at water control structures in the district

Challenges  There are many different stakeholders with different and sometimes conflicting interests.  It is not possible to meet the needs of all stakeholders at the same time.  It is not uncommon to have perceived high or low water issues coming from the same group at the same time

Complicated System  As water moves through a watershed any changes at one dam affect the ones below it  Operations must be coordinated between dams and agencies to ensure the objectives of the Water Management Plan are met

Too Much Water  Water Levels can change rapidly in response to runoff.  In the Parry Sound District Spring is typically the most volatile time of year.  Large volumes of snow combined with rain can result in rapidly rising water levels.  Often the volume of water is greater than can be passed through a dam and water levels rise to damaging levels Water levels 30cm above summer levels generate many complaints and can damage infrastructure Lakes in the Parry Sound District have extensive valuable infrastructure in the Flood Plain

Too Little Water  Low Water Levels caused by dry periods can result in difficulties with navigation and can be harmful to the environment  During dry periods it is important to maintain discharge in reached downstream of lakes. This can make it impossible to keep lakes at the preferred level for navigation

How do we deal with variability?  Higher spring levels so water is stored in case of a dry summer  Winter Drawdown to make room for the melt  Operators monitor weather conditions closely and make decisions based on forecast and observed information

Communication  Helping the public understand what is happening  Providing warning to partners  Receiving and using information

Water BodyDrainage Area % of Total Big East River732km % Buck River219km % Lake Vernon (Not including Big East and Buck River) 139km % Fairy Lake Not including Vernon) 56km 2 4.6% Peninsula Lake62km Total (at Dam)1208km 2 100% Drainage Area Fairy Lake has a large drainage area Approximately 1/5 of the entire Muskoka River Watershed area is above Fairy Lake 80% of all the water that goes through the Huntsville Dam travels through Lake Vernon Lake Vernon Watershed Pen & Fairy Lake Watershed

Muskoka River Water Management Plan Changes vs. Hackner Holden LakeSpring Draw DownSpring PeakFall Draw DownWinter Peak Huntsville Lakes7cm higherUnchanged2cm lowerUnchanged Lake of Bays10cm higherUnchanged15cm lowerUnchanged Mary Lake24cm higher12cm higher6cm lowerUnchanged Lake Muskoka20cm higher8cm higherUnchanged-earlier12cm higher Normal Operating Zone =Unchanged

June-August 80% within a 15cm 50% within 10cm In future the mean will probably gradually move more towards the green line

During an average spring ~100CMS the water level at the G8 centre is approximately 30cm higher than at the dam! During periods of high flow the volume of water entering Fairy Lake exceeds what can leave it and water levels rise the further upstream you travel from the dam

Although hydro production is important it is not the primary objective for water management and discharge routinely exceeds the plant capacity at high falls. There are also requirements restricting the minimum outflow from the lakes in a dry summer water levels will be low but the goal is to protect downstream ecology not to generate hydro

Questions?

Pre 2006