Category Archives: Credit Valley Conservation

Flood Watch Issued for Lake Ontario Shoreline

The averaged Lake Ontario elevation for yesterday (Toronto, Apr-30-2019) was at 75.41 metres (m) above International Great Lakes Datum (IGLD).  Today, the lake elevation is near 75.46 m.  Flood damages in 2017 occurred at a Lake Ontario elevation of 75.45 m when waves generated during a storm event overtopped and damaged several shoreline structures.  The latest forecast (Apr-30-2019) provided by the Lake Ontario St Lawrence River (LOSLR) Board of the International Join Commission (IJC) is projecting maximum Lake Ontario elevations ranging from 75.65 to 75.95 m for late May to Early June with the upper range being 2 centimetres above the record set in 2017.  The lake damage threshold elevation of 75.45m does not account for wave generated by winds which can increase flood elevations and cause additional damages; this is especially true with onshore winds associated with storms.

Information provided by the Surface Water Monitoring Centre (SWMC) of the Ministry of Natural Resources and Forestry (MNRF) along with the IJC is indicating that rain and snow melt within the Great Lakes and St Lawrence River basin have resulted in high river and lake levels.  Major flooding is currently (Apr/May, 2019) occurring in Eastern Ontario and Quebec due to a combination of high flows in the St Lawrence and Ottawa River. 

The current Lake Erie water elevation is at a new record high for the-end-of-April.  Flows discharging from Lake Erie via the Niagara River, over the Falls, into Lake Ontario are uncontrolled.  Flows discharging out of Lake Ontario into the St Lawrence River are controlled at the Moses-Saunders (MS) Dam.  The MS Dam is operated in accordance to Plan 2014 from IJC which takes into consideration, and balances, the impacts of downstream flooding with higher Lake Ontario levels.  Over next several weeks, Lake Ontario levels will increase and will remain high for the season due to high inflows from Lake Erie and restricted Lake Ontario outflows to mitigate downstream flooding along the St Lawrence and Ottawa Rivers. 

For more information on the Lake-Ontario-St-Lawrence-River-Board and Plan-2014 please visit:

https://ijc.org/en/loslrb

Onshore winds, especially those associated with storms systems, can generate waves resulting in shoreline erosion, flooding and damages.  Wind and wave conditions are provided by Environment Canada via the following website: 

https://weather.gc.ca/marine/region_e.html?mapID=11

Wind gusts at Cawthra Park in south Mississauga are available through the CVC monitoring network: 

Current Lake Ontario level is available from (add 74.2m for IGLD):

https://waterlevels.gc.ca/eng/find/region/6

CVC will continue to monitor weather and lake conditions.  This Flood Watch will be updated by Fri-Jun-14-2019

Watercourses discharging directly into Lake Ontario may be impacted by backwater from the lake.  Residents and visitors to the Lake Ontario shoreline areas should use extreme caution and obey all closure notices for trails and pathways.  As lake levels increase, certain areas may be cut off or isolated. 

Spring Safety Message: Be Careful Around Waterways

Hazardous conditions on and around bodies of water

Credit Valley Conservation (CVC) is reminding residents of the dangers on and near local streams, rivers, ponds and lakes, particularly around this time of year. CVC urges people to exercise caution, and keep family members and pets away from the edges of all waterways as warmer spring weather approaches.

In spring we look forward to warmer weather and being outdoors. Warmer weather, however, usually brings rain, melting snow and shifting ice which can contribute to higher, faster flowing water in watercourses. Slippery, unstable streambanks and extremely cold water temperatures can also lead to very hazardous conditions close to any water body.

The Credit River Watershed has received a significant amount of snow this winter. A few recent thaws have helped decrease the existing snowpack. Melting snow due to warmer temperatures combined with spring rainfall and frozen ground conditions could contribute to higher water levels and increased water speeds in local watercourses.

There is still significant ice cover throughout the watershed. Several ice jams remain grounded along the Credit River at Barber (Paper) Mill Dam in Halton Hills, the Ferndale Park in Caledon and at Meadowvale Park in Mississauga. 

Remaining ice jams and ice cover on watercourses will weaken and become unstable with warmer temperatures. CVC continues to work with municipal emergency services to keep them constantly informed about current and changing conditions within local watercourses. 

CVC urges people to exercise caution and keep family members and pets away from the edges of all waterways and off frozen water bodies, which are extremely unsafe.

For more information, contact CVC at (905) 670-1615.

WATERSHED CONDITIONS STATEMENT

Friday, Saturday and Sunday’s forecast calls for continued warm daytime temperatures across Southern Ontario.  Temperatures will peak at the mid to high single digits.  The current forecasted rainfall amount ranges from 10-20 mm over the weekend with an additional 5-10 mm of rain possible from convective precipitation (thunderstorm) overnight Saturday into Sunday morning.  On Sunday sustained winds up to 65 km/h from the west-southwest are forecasted with gusts exceeding 100km/h. 

Several ice jams remained grounded along the Credit River at the Ferndale Park, Barber (Paper) Mill Dam and Meadowvale Park.  Approximately 1.5 km of ice is backed up at the Barber Mill Dam in Glen Williams.  New river ice has formed at some locations since the previous ice break up event.  

The forecasted maximum 30mm of rain along with melting of the existing snow pack would be sufficient to break up the newly formed river ice, mobilize the grounded ice jams and potentially overtop the Barber Mill Dam sending ice downstream.  

Furthermore, the ice will lose its strength as the temperatures increase.  Under the proper loading and temperature conditions, it is possible for the existing grounded ice jam to shift or collapse under its own weight.  Once any type of movement initiates, the grounded ice jam may no longer be stable.  This is especially true if the movement occurs near the front (downstream or toe end) of the jam where a few critical pieces of ice could be holding back the entire ice jam.  

All watercourses in our area will experience higher than normal water levels.  An ice jam breaking lose will create extremely hazardous conditions.  As a result, local streams and rivers will become dangerous, especially in the vicinity of culverts, bridges and dams.  Children should be warned to stay away from all watercourses.  Furthermore, residents should heed to the warnings of first responders. 

High winds on Sunday could create hazardous conditions along the shoreline.  The forecasted west to southwest winds may result in higher lake levels, erosion of shorelines and trails along the shoreline could be impacted.  

CVC will continue to closely monitor weather and water levels in the watershed.  The Flood Outlook Statement will be in effect through Tue-Feb-26-2019 or until further notice. 

For more information on this Flood Outlook Statement, contact the CVC during office hours at 905-670-1615.  To report a flood afterhours, please call 1-800-215-8505.  Media inquiries should be directed to Maureen Pogue, 905-670-1615, ext. 242 or 647-271-5643. 

Call 911 if you require assistance from Emergency Services. 

WATERSHED CONDITIONS STATEMENT

Credit Valley Conservation (CVC) is advising that Environment Canada is forecasting mixed precipitation of 5-10 mm, along with warmer temperatures for this weekend. Rain will begin on Sunday with temperatures up to +3oC and continue into Monday with light showers and temperatures up to +7o C.

The mix of above-zero temperatures, rain, and partial melting of the snowpack are expected to increase runoff, water levels and flows in the watercourses throughout the watershed. With increased temperatures, there is a possibility of breaking up of the ice cover in watercourses, resulting in ice jams and increased water levels.

While flooding of the Credit River and its major tributaries is not expected, higher water levels and flows will result in local streams and rivers becoming dangerous, especially in the vicinity of culverts, bridges and dams.  Children should be warned to stay away from all watercourses.   

CVC will continue to closely monitor weather and water levels in the watershed.  The Watershed Conditions Statement for Water Safety will be in effect through to Tuesday February 5th, 2019, or until further notice.

For more information on this Water Safety Statement, contact CVC during office hours at 905- 670-1615.  To report a flood afterhours, please call 1-800-215-8505.

FLOOD WATCH – Message #1

Issued 2:30pm Friday, April 13th

Credit Valley Conservation advises that 2-5 mm of precipitation has fallen throughout the watershed since Thursday with an additional 80-100 mm of precipitation expect over the next five days in the form of rain or freezing rain.

Water levels along the Credit River and its major tributaries have increased due to the rain and will continue to rise.  Some minor flooding in low lying areas is anticipated.  These areas may include Townline Road in Orangeville, Inglewood, Terra Cotta, Crestview Lake and Caledon Lake in Caledon.

The public is reminded to exercise extreme caution around all water bodies.  Banks adjacent to rivers and creeks are very slippery at this time and when combined with current weather conditions, pose a serious hazard.  People are encouraged to keep their children and pets away from all watercourses and off frozen water bodies, which will be extremely unsafe.

CVC will continue to monitor the watercourse and the weather.  This Flood Watch will be updated by 2pm Monday April 16, 2018.

For more information on this Flood Watch message, contact CVC during office hours at 905- 670-1615.  To report a flood afterhours, please call 1-800-215-8505.

To view current watershed conditions, visit our real-time monitoring website:  http://www.creditvalleyca.ca/watershed-science/watershed-monitoring/real-time-monitoring/