340 likes | 391 Views
Mississagua Water Level Update Spring 2013 and Recent flooding in Haliburton . Presentation to CCRAI June 22, 2013 By Ted Spence – CCRAI representative on CEWF CEWF.ca. Reminder of a Few Facts about the TSW. Stretches from Georgian Bay to Lake Ontario
E N D
Mississagua Water Level Update Spring 2013 and Recent flooding in Haliburton Presentation to CCRAI June 22, 2013 By Ted Spence – CCRAI representative on CEWF CEWF.ca
Reminder of a Few Facts about the TSW • Stretches from Georgian Bay to Lake Ontario • Flows west to Lake Simcoe and Southeast to Lake Ontario with the divide in the area of Kirkfieldjust west of Balsam Lake • Eastern section includes the Kawartha Lakes and the Trent River system as well as 41 reservoirs and more than 20 Flow-Through lakes (RAFT Lakes) in the so called “Haliburton Sector” • Climate change models suggest a future of more variability and earlier spring runoff, less summer rain and more evaporation, and more extreme events.
The Reservoirs • In the “Haliburton Sector” there are 35 reservoirs - 17 in the Gull River system (Kennisis largest in Gull), 13 in the Burnt River System (Drag the Largest in Burnt), and 5 in the central area including the Mississagua chain of lakes which is the largest single reservoir storage on the system. • The reservoir systems are very complex to manage with flow constraints at some points and flow through lake levels to consider. • Minimum flow at Peterborough for water supply and sewage treatment is the most important low flow constraint. • The reservoirs are not a flood control system particularly in late spring! • Our section one of the most straight forward.
Consider Our Water level Experience in recent years as context for 2013 • 2009- normal year except for very high water as ice went out causing shore damage • 2010- very little spring runoff and reservoirs did not fill until late July • 2011- normal year until TSW began rapid drawdown in mid August • 2012- much lower than average water levels beginning in late May • 2013 – some of highest flows on record and extreme flooding in Haliburton area in April and again in May
Spring 2013 -Two Extreme Rainfall Events • Early April reservoirs filling and at near normal levels and then 2 extreme rainfall events!!! • Reservoirs are not operated to absorb major spring storms! • April 17, 18 and 19 – about 1 inch of rain here but up to 3 inches over Haliburton on to still frozen ground caused extreme flooding on some reservoirs in Gull and Burnt River systems and in Minden. • May 20, 21 and 22 – more than 1 inch of rain here and again 3 inches over Haliburton causing more high levels on reservoirs but controlled flows and minimal flooding.
Mississagua Dam April 21, 2013two spillways active and 7 logs out
April 21, 2013 - Level gauge reads 2.63 m or 19 cms above “full”
Mississagua River below the Dam on April 21, 2013 with 7 logs out
Below Horseshoe Dam 0n Gull River System Late April 2013 (All logs in and wing with sand bags)
What is the Coalition for Equitable Water Flow (CEWF) that CCRAI is a Member of? • The Coalition is a Volunteer Organization • Formed in 2006 • Represent interests of 40,000 shoreline property owners in “Haliburton Sector” of Trent watershed with regard to water management issues • Includes “Reservoir” and “Flow-Through” (RAFT) lakes • Sub-watersheds included: • Gull, Burnt & Mississagua rivers plus Nogies, Eel’s & Jacks creeks
Cewf.caLinks to level forecasts and latest Parks Canada water levels
New and Current Issues June 1013 • Review of 2013 spring flood events and possible changes to reservoir operations – BIG ISSUES ??? • Impacts of new 2012 organization amalgamating Rideau and Trent Canal Systems – initial impressions positive. • Water management vs. Canal Operations - recent focus on Lock hours and fees. • Barry Devolin’s Private Members Bill – does not seem to really address reservoir interests or separate out water management. • Results of Dam safety review on Mississagua dam from summer 2012 – CEWF and CCRAI have requested details.