Flood and Ice Jam Event (January 12, 2018) Summary
Conditions Prior to the Weather Event
- Water levels were normal, with most streams and creeks iced over. Existing snowpack with 50-75mm of Snow Water Equivalent (SWE). Existing ice cover between 3-7 inches.
- The Surface Water Monitoring Centre advised CAs that there was a large system moving into the area on January 11, bringing potentially 15-25mm of rainfall with an increase in temperature to 10 degrees or warmer before rapidly dropping back to below freezing in the afternoon of January 12.
- KCCA issued a Watershed Conditions Statement—Water Safety on January 10, 2018 at 3:30 PM for unstable ice and slippery banks and potentially fast flowing water. Ice survey in Port showed some open water at Southwold Wall, but all ice covered elsewhere.
- KCCA issued a Watershed Conditions Statement—Flood Outlook on January 11, 2018 at 4:30 PM after a quick tour of the watershed indicated that most of the existing snowpack had melted and rain was steadily falling. Approximately 20 mm of rain fell throughout the watershed on January 11. There was more open water at Southwold Wall, but ice cover good in other areas.
During the Weather Event
- As temperatures dropped over January 12, rain turned into freezing rain and ice pellets (12:00 PM) and then into snow which caused near zero visibility at times (2:30 PM).
- Surface Water Monitoring Centre (MNRF) continually updated CAs with new information from the storm tracker.
- Recorded rainfall intensities over the duration of the event were low, ranging from 1 to 3 mm/hr with occasional increase to the 2 to 4 mm/hr range.
- Winds coming off of Lake Erie were not conducive to storm surge conditions over the duration of the event.
- Lake Erie was 60.89% frozen.
- Total rainfall amounts of 38 mm to 42.75 mm of rain fell throughout the watershed over January 11-12, 2018 which was almost twice the forecasted amount of 15 to 25 mm.
Kettle Creek Conservation Authority Actions
- KCCA Staff updated the Municipality of Central Elgin at 9:15 AM, January 12, with current watershed conditions and concerns. Municipal staff decided to contact a local contracting company to provide ice breaking service with a backhoe to help move the ice jam through to the harbour.
- Flood Warning media release issued by KCCA on January 12, 2018 at 11:15 which provided details on the flood event. Bankfull and/or flooding conditions were imminent or already occurring in the watershed. There was particular concern for the village of Port Stanley due to an ice jam located near Lion’s Park and Stan’s Marina.
- Continuous monitoring of weather conditions and real-time watershed monitoring of precipitation, water level and flow using the stream gauge and rain gauge network
- KCCA flood watch team deployed to monitor key areas of historically flood prone locations, as well as continuous monitoring of dams over the duration of the event.
- Ongoing updates to social media of photos to Facebook, Twitter and Instagram.
Dams and Erosion Control Structures
- Continuous monitoring of Dalewood Dam, Union Dam and Southwold Wall.
- Flows observed moving well over the structures with no major debris or blockages.
- Most historically flood prone areas in the watershed exceeded bankfull conditions and extended into natural floodplain areas.
- No debris blockages or overtopping of road crossings were observed.
- At this time no confirmed flooding of structures were identified through field observations
- Ponding observed in many agricultural fields throughout the watershed.
- Dodd Creek peaked at 12:00PM on January 12, 4.061m water level and 54.8 cubic meters per second flow.
- Upper Kettle Creek peaked at 10:20AM on January 12, 7.954m water level and 63.9 cubic meters per second flow.
- Lower Kettle Creek peaked at 3:20PM on January 12, 9.454m water level and 182 cubic meters per second flow.
Dodd Creek Water Level and Discharge (January 12, 2018)
Kettle Creek at Ferguson Line Water Level and Discharge (January 12, 2018)
Kettle Creek at Fingal Line Water Level and Discharge (January 12, 2018)
A look back at 2009: Comparing Two Events
Date: February 11-12, 2009
Main Cause of Flood: brief period of increased temperature caused surface runoff from melting snow, combined with rain and an ice jamming in Port Stanley.
Total Rainfall (48 hours): 48 mm
Max Temperature: 9.4°C
Max Flow: 147 cubic meters per second (Fingal Line)
Flood Statistics (Peak, Max Level, Max Flow):
Dodd Creek: 5:00 AM at 4.3m, 64.4 cms
Upper Kettle Creek: 2:00 AM at 8.5 m, 112 cms
Lower Kettle Creek: 10:00 AM at 9.9m, 167 cms
Date: January 12, 2018
Main Cause of Flood: brief period of double digit temperatures caused surface runoff from melting snow, combined with rain and ice jamming in Port Stanley.
Total Rainfall (48 hours): 38-43 mm
Max Temperature: 11.4°C
Max Flow: 182 cubic meters per second (Fingal Line)
Flood Statistics (Peak, Max Level, Max Flow):
Dodd Creek: 12:00 PM, 4.06m, 54.8 cms
Upper Kettle Creek: 10:20 PM, 7.95m, 63.9 cms
Lower Kettle Creek: 3:20 PM, 9.45m, 182 cms