Flood Forecasting and Warning Program

Information about the Flood Forecasting and Warning Program, which prepares provincial and local authorities in the event of a flood.

Special Lake Ontario Flood Watch

Special Lake Ontario Flood Watch Issued By Ministry of Natural Resources' Surface Water Monitoring Centre for May 31st, 2017

Current flood information

Flood information updated as of: July 22, 2017 - 8:00 am

Ontario flood map

Provincial Watershed Conditions Statement for Southern Ontario issued by Surface Water Monitoring Centre of the Ministry of Natural Resources and Forestry Friday July 21, 2017 at 11:30 AM

Locally issued flood messages

Issued by MNRF Districts and Conservation Authorities

MNRF Districts


    Conservation Authorities

    • Cataraqui Region - Flood Warning Extended For Lake Ontario & St. Lawrence River - June 29, 2017
    • Central Lake Ontario - Flood Warning Update - Lake Ontario Shoreline - June 29, 2017
    • Credit Valley - Lake Ontario Flood Watch - Message #3 - July 14, 2017 4:00 pm
    • Crowe Valley - Watershed Conditions Statement – Water Safety - July 19, 2017 10:00 am
    • Ganaraska Region - Flood Watch - Lake Ontario - June 20, 2017
    • Hamilton - Watershed Conditions Statement: - July 18, 2017
    • Lower Trent - Flood Warning Update for Lake Ontario/Bay of Quinte - July 14, 2017 2:00 pm
    • Mississippi Valley - Flood Watch for Little Marble Lake and Dalhousie Lake - July 19, 2017 4:00 pm
    • Quinte - Flood Warning For Bay Of Quinte and Lake Ontario Shorelines in the Quinte Conservation Watersheds - June 28, 2017
    • Rideau Valley - Rain Causing Higher Water Levels in Rideau River Watershed - July 14, 2017 12:30 pm
    • South Nation - Flood Watch St. Lawrence - Update #7 - June 22, 2017
    • Toronto and Region - Watershed Conditions Statement – Lake Ontario - May 9, 2017

    River Regulatory Agencies

    Provincial Message

    Issued to Local Authorities by the Surface Water Monitoring Centre


    MNRF Districts

    Algonquin Park, Aurora, Aylmer, Bancroft, Dryden, Fort Frances, Guelph, Kemptville, Kenora, Midhurst, Parry Sound, Pembroke, Peterborough, Red Lake, Sioux Lookout, Thunder Bay

    Conservation Authorities

    Ausable Bayfield, Cataraqui Region, Catfish Creek, Central Lake Ontario, Credit Valley, Crowe Valley, Essex Region, Ganaraska Region, Grand River, Grey Sauble, Halton, Hamilton, Kawartha, Kettle Creek, Lake Simcoe Region, Lakehead Region, Long Point Region, Lower Thames Valley, Lower Trent, Maitland Valley, Mississippi Valley, Niagara Peninsula, Nottawasaga Valley, Otonabee, Quinte, Raisin Region, Rideau Valley, Saugeen, South Nation, St. Clair Region, Toronto and Region, Upper Thames River

    Weather Situation

    A series of low pressure systems and unsettled weather conditions are set to dominate the weather conditions in the province for Saturday, Sunday into Monday. Primary concerns are widespread scattered rainfall, heavy sometimes locally for northwest Ontario and southern Ontario in these coming days.

    On Saturday there is a forecast of 10 to 20 mm of rainfall for southwest Ontario plus an additional risk of 10 to 25 mm of rain in the form of isolated thunderstorm for the region. Similarly in the northwest of the Province there is a risk of 20 to 30 mm of widespread rainfall plus an additional 10 to 25 mm in the form of thunderstorms.

    For Sunday, the southern region could see an additional 10 to 20 mm of widespread rainfall with the higher values forecast for regions to the south of Georgian Bay and in the Ottawa River Region. There is a risk of additional rainfall due to thunderstorms for locations anywhere in the southern region. The exact track and timing of these rainfall events are still unclear at this time.

    For Monday unsettled weather conditions will continue to dominate weather conditions in the south and in the northwest which could bring additional widespread rainfall accompanied with thunderstorms in the regions.

    Cumulative 5 day rainfall totals for northwest not including thunderstorm could be 30+mm but the number could be higher locally due to thunderstorms in any or all of these coming days. Similarly in the southeast and southwest cumulative 5 day rainfall not including thunderstorms could be 45 and 35 mm respectively. Additional rainfall in the form of thunderstorms in any or all of these days could result in higher numbers locally.


    NOTE: Lake Ontario and Lake Erie levels continue to be elevated and are forecast to remain so for all of the month of July. See our Special Lake Ontario Flood Watch for more information at www.ontario.ca/flooding.

    Stream flow and levels are moderately high in northwest Ontario due to recent rainfall in the region. Similarly stream flow and reservoir levels are moderately elevated for this time of year due to recent rainfall in the Southern region. Recent rainfall and active weather in the region have reduced the capacity of soils to store additional water and thus can produce runoff more readily resulting in high water and flooding conditions locally in a short time. Short and intense storms, such as the one associated with this evolving weather system has the potential to cause increased runoff and result in localized flooding anywhere in the forecast region.

    Close attention should be paid to local flood conditions reports from conservation authorities and municipalities, and as always, a close watch on meteorological conditions, including thunderstorm alerts, is recommended.

    This message will be in effect until (or updated before) Monday July 24, 2017 at 5 PM.

    Flood Message Definitions

    Provincial flood messages

    There are 2 types of provincial flood messages:

    • the Provincial Flood Watch, which provides consistent and timely technical information about the potential for flooding
    • the Provincial Watershed Conditions Statement, which provides information on provincial watershed conditions as they relate to flood potential, and an outlook on expected spring flood conditions

    Local flood messages

    There are 3 types of local flood messages:

    • flood warning: flooding is imminent or already occurring
    • flood watch: there is the potential for flooding
    • watershed conditions statements: flood Outlook (an early notice of the potential for flooding based on heavy rain, snow melt etc.) and water safety information.

    Who to contact for flood information

    Your local Conservation Authority is responsible for local flood messaging.

    Your local municipality is responsible for on-the-ground flood response.

    If you live in a community that is not serviced by a conservation authority, any flood watches or flood warnings in your area are issued by the nearest Ministry of Natural Resources and Forestry district office.


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    Updated: August 19, 2016