Cataraqui Conservation Issues |Flood Watch for Inland Lakes and Streams - March 9

Kingston – Cataraqui Conservation has issued a Flood Watch today for inland lakes and streams due to snowmelt and rainfall runoff, resulting in elevated flows and water levels and the increased likelihood of flooding in certain portions of the region.

Weather Situation:

The spring freshet (snowmelt) period is underway. The region experienced 10 degree C+ temperatures on Saturday, March 7, accompanied by 6 to 20mm of rain. Some localized areas may have seen rainfall amounts of 30mm+.

An additional 23 to 45mm of rainfall is forecast for the period of Tuesday, March 10 to Thursday, March 12. Current forecasts are suggesting the bulk of precipitation will fall as liquid rain, mostly on Wednesday, March 11.

Temperatures are expected to stay above zero until Thursday, March 12, with daytime highs approaching or exceeding 10 degrees C on March 9 and 10. Starting Thursday, March 12, temperatures are expected to stay mostly below zero for several days.

Conditions:

Streamflows and lakes levels are rising from recent rainfall and ongoing snowmelt runoff. Many gauged creeks are seeing high levels with Water Survey of Canada gauged creeks seeing all-time highs for March 9.
A portion of the original snowpack remains in-place and will continue a rapid melt during the warm days ahead. The ground has limited ability to infiltrate since it is either still partially frozen and/or nearly saturated from recent rainfall and ongoing snowmelt.

Water Managers continue to monitor water levels closely and make discharge adjustments to maintain target water levels. Water management cannot prevent flooding. It seeks to balance negative impacts, as much as possible, as excess water moves through the system. Target water levels generally trend upward through March to prepare for the summer recreation season.

Risks:

Runoff from snowmelt and rainfall over the coming days will result in further increases to streamflows and lake levels. Levels could rise quickly, especially if the higher forecasted rainfall amounts materialize. In some locations we could see streamflows and water levels not seen in many years (e.g., 2014 and 2017 high-water periods).

Widespread flooding is NOT expected at this time. However, flooding of low-lying areas is expected. Localized roadway inundation is possible where drainage infrastructure is overwhelmed and at some creek crossings. Residents in flood-prone or low-lying areas, historically susceptible to flooding, are advised to remove items stored in the floodplains of area watercourses and lakes.

If you witness flooding and/or require assistance, your first point of contact is the local municipality.
Specific gauged creeks already experiencing all-time high flows for March 09 include:

• Wilton Creek
• Millhaven Creek
• Collins Creek
• Lyn Creek

Additionally, Little Cataraqui Creek West Branch and Buells Creek are much above normal.
Further flow and water level increases are anticipated.

Millhaven Creek flow through the village of Sydenham, immediately downstream of Sydenham Lake Dam is currently about normal but is expected to become elevated in the coming days from snowmelt and rainfall runoff that will raise the water level in the lake and increase discharge downstream.

Specific locations that could see water levels well above normal seasonal averages include*:
Gananoque River System

• Upper Beverley Lake & Delta
• Lower Beverley Lake
• Gananoque River – the reach between Marble Rock Dam downstream to the 401 causeway (includes Marble Rock Road

*Connected lakes and watercourses, associated with the above lists, may also be affected.
Watch for additional locations added to the above lists in subsequent flood message updates.

The consistently cold temperatures this winter have resulted in thicker ice cover on lakes and streams. Ice cover will weaken and may begin to break up and move leading to possible localized ice jam flooding, especially in areas with a history of ice jamming. There’s also the possibility of shoreline damage (e.g., to docks) from the thick ice, especially where it’s still attached to the shore.

Cataraqui Conservation is urging caution around all dams (inflow and outflow channels) and fast-flowing watercourses. Respect the hazards in these areas by obeying all warning signs, and keep away from booms, buoys and barriers. Stay well back from the water’s edge above and below dams and hydroelectric stations. Creek banks and lake shorelines may be slippery, increasing the chance of falling in.
Ice conditions will deteriorate rapidly during warmer temperatures. Cataraqui Conservation does not measure ice thickness for advising the public about ice conditions for recreational activities.

Ice conditions can vary considerably from one waterbody to the next and within a single waterbody. No ice is without some risk. Visit lifesaving.org for ice safety information.

Staff will continue to monitor conditions and forecasts and will update statements as needed. This Flood Watch will remain in effect until (or updated before) Wednesday, March 18, 2026, at 11:59 PM.

For up-to-date flooding information, please visit our flood forecasting and information page at https://cataraquiconservation.ca/pages/flood

See below for watershed conditions terminology:
Normal: No flood conditions exist

Watershed Conditions Statement – Water Safety: High flows, unsafe banks, melting ice or other factors that could be dangerous for recreational users such as anglers, canoeists, hikers, children, pets, etc. Flooding is not expected.

Watershed Conditions Statement – Flood Outlook: Early notice of the potential for flooding based on weather forecasts calling for heavy rain, snow melt, high wind or other conditions that could lead to high runoff, cause ice jams, lakeshore flooding or erosion.

Flood Watch: Flooding is possible in specific watercourse or municipalities. Municipalities, emergency services and individual landowners in flood-prone areas should prepare.

Flood Warning: Flooding is imminent or already occurring in specific watercourses or municipalities. Municipalities and individuals should take action to deal with flood conditions. This may include road closures and evacuations.