’50 in 50′ Series: Trent River Flooding (2014)

50in50

Lower Trent Conservation is celebrating its 50th anniversary! To commemorate this milestone occasion, we have released our ’50 in 50′ historical blog series. This special series features 50 articles highlighting some of the achievements, milestones and events of the past 50 years. We hope you enjoy them!

In 2014, the people living along the Trent River experienced flood conditions from the beginning of April until mid-May. Flooding in vulnerable areas along the Trent River is something that residents should be prepared for every year. Unfortunately, many homes were built in the flood plain of the Trent River prior to flood plain mapping and regulations.

The winter of 2014 was a typical Ontario winter with very few thaw periods. By late winter, the snow pack in the Lower Trent watershed region was significantly above average – about 50 cm of snow on the ground that held the equivalent of about 160 mm of water (~6.2”). By mid-March, daytime temperatures were reaching above freezing, which started to reduce the snow pack. In early April, about 35 cm of snow still remained on the ground that held about 120 mm of water. Temperatures were beginning to stay above zero with rain in the forecast.

Lower Trent Conservation issued a Flood Watch for local creeks and streams on April 3. On April 4, 25 mm of rain had fallen with another 30 mm of rain on April 7-8. This precipitation started the Spring 2014 Freshet (or flood) in the Lower Trent watershed region. All the smaller creeks including Mayhew, Cold, Rawdon, Mill, Trout, Butler, Salt, Colborne, and Shelter Valley Creeks peaked on April 8, with flows ranging from typical 2-year flows (50% chance of occurring in any year) to 10-year flows (10% chance of occurring in any year). No significant flooding concerns were reported – a typical spring runoff!

However, due to its size, the spring freshet had not yet started along the Trent River system. The Trent River flows from Rice Lake to the Bay of Quinte, through the Lower Trent watershed, but the Trent River watershed extends far to the north. The drainage area for the Trent River is over 12,000 square kilometres with its headwaters on the fringes of Algonquin Provincial Park. All the water flowing through the upper reservoir lakes in the Haliburton region, the Kawartha Lakes, Lake Scugog, and the Otonabee and Crowe Rivers eventually flow down through the Trent River before emptying into the Bay of Quinte at Trenton. In 2014, the large snowpack in the upstream (northern) portions of the Trent River watershed contributed to the large flows in the system for a long time after all the snow in the local area was gone.

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Residential flood damage protection (2014)

Here’s what happened:

  • A Flood Watch was issued for the Trent River on April 9. The local streams had significantly contributed to the Trent River flow, along with an additional 10 mm of rain on April 9th.
  • The Flood Watch was updated to a Flood Warning on the Trent River on April 10.
  • The Crowe River inputs to the Trent System peaked at a flow of 232 m3/s on April 19.
  • On April 23, the flows in the lower portion of the Trent River (Campbellford to Trenton) peaked around 700 m3/s for 3 days. This amount of water is equivalent to a 10-year flow on the Trent River in this area (or has a 10% chance of occurring in any year).
  • Water levels on Rice Lake peaked on April 24th and on April 26th. The highest flows in the upper portion of the Trent River (Rice Lake to Healey Falls) reached 528 m3/s, which exceeded 25-year flows for 4 days (has a 4% chance of occurring in any given year).
  • The Municipality of Trent Hills declared a State of Emergency on April 24th and the State of Emergency was removed on May 23rd.
  • Lower Trent Conservation staff conducted a flyover of the Trent River System from Rice Lake to the Bay of Quinte on April 28, 2014.
  • During the entire flood season, Lower Trent Conservation staff participated in daily phone calls with local Conservation Authorities on the Trent River System, Ministry of Natural Resources and Forestry, Parks Canada (Trent-Severn Waterway), and Ontario Power Generation from April 8 to May 3.
  • During the Flood Watch, Lower Trent Conservation staff communicated daily with Municipalities affected by the flooding.

Overall, no homeowners were evacuated, but many people sustained flooding impacts on their property and inundation of their septic systems. Sandbags were distributed by the affected Municipalities and these, along with plastic sheeting and pumps, were used by homeowners to protect their homes.

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Aerial view of flooding along the Trent River (2014)

But the 2014 flood on the Trent River was not the worst on record – it was the second highest flow observed at Healey Falls since 1950. Higher flows were observed in 1951. Lower Trent Conservation regulates development along the Trent River to the 100-year event. Fortunately, we did not see this extent of flooding on the Trent, as many more landowners would be impacted and significant property damage would result.

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