Southern Lake levels: Update 14, 15-July 2021
Hi All,
This is the 14th email update sharing information about the flood situation for the Southern Lakes and Laberge. New flood info is highlighted in yellow. New flood response info is highlighted in blue.
Southern Lakes are holding steady over last 5 days, Yukon river in Whitehorse is dropping slightly, and Laberge has slowed to less than 1cm rise over the past 24 hours. Record flood levels have been set by Bennett, Tagish, Marsh and Laberge reaching 16 cm, 12 cm, 22 cm and 43 cm (6-1/2", 4-1/2", 8-1/2" and 17") respectively above the 2007 flood peaks. These record levels have been reached a month and a half earlier than normal peak times for the lakes.
Flood response:
* Southern Lakes Flood Incident Management Team is being led by Mike Smith
* The Incident Management Team information line is: This email address is being protected from spambots. You need JavaScript enabled to view it. or 867-332-7084
* If you or a neighbour you know needs some help, please let me or the flood team know
* Sand and sand bags are now available at 9 locations
* Marsh Lake: South McClintock Road / Boat launch off Nolan Drive / Community Centre
* Tagish: Community Centre / Cemetery
* Laberge: Horse Creek Road / Jackfish Bay / Hootalinqua fire hall
* Carcross: by the airstrip
* The flood team is prioritizing primary residences that are most at risk of flooding
* They have retained flood specialists from the prairies and Canadian Armed Forces (who have just been extended for another 2 weeks)
* Sandbagging has now exceeded 1 million bags (compared to 250,000 used in 2007)
* Landfill hours have now been extended to 7 days a week in support of flood defence activities
* As of 9-July, the Southern Lakes + Laberge + Kusawa Lake flood was declared a state of emergency
* As of 11-July evacuation alerts included parts of Army Beach, South McClintock and Lewes (click here<https://yukon.ca/sites/yukon.ca/files/evacuation_alert_-_areas_of_marsh_lake_and_lewes_river_road_-_july_7_2021.pdf>), Tagish (click here<https://yukon.ca/sites/yukon.ca/files/evacuation_alert_-_areas_of_tagish_-_july_10_2021.pdf>) and Laberge (click here<https://yukon.ca/sites/yukon.ca/files/evacuation_alert_-_areas_of_lake_laberge_-_july_11_2021.pdf>)
* Alerts are a precaution so residents prepare in case we hit an unexpected significant wind or rain event which overwhelms flood defences
* As of 13-July we issued our first evacuation order due to concerns that groundwater had made a foundation unstable in Shallow Bay (click here<https://yukon.ca/sites/yukon.ca/files/evacuation_order_-_shallow_bay_road_amended.pdf>)
Flood info:
* Southern Lakes winter snow load was more than twice our average
* 19-March 2021, Yukon Energy (YEC) opened the locks at the Lewes River control structure (roughly 2 months early)
* YEC reopened the boat lock and removed the gates completely
* YEC removed driftwood from in front of the control structure last week and they have removed most of the gates
* YEC has dropped elevation of Schwatka by -0.93 m to try to increase flow through Miles Canyon
* Some roads are now flooded isolating access to some homes
* Bank erosion due to wave action is significant
* There remains a lot of uncertainty with all projections and we will need to monitor the rise closely
* Dr. Benoit Turcotte (research hydrologist) from Yukon University wrote an article explaining the flood (click here<http://scholar.yukonu.ca/bturcotte/blog/high-water-levels-yukons-southern-lakes?admin_panel=1>)
* Flood warning for Southern Lakes was updated on 15-July (<https://yukon.ca/sites/yukon.ca/files/env-flood-warning-southern-lakes-july-2-2021.pdf>click here<https://yukon.ca/sites/yukon.ca/files/public_flood_update_-_july_15_fnl_1.pdf>)
* As of 7-July the boil water advisory was expanded for Southern Lakes, Laberge, Kusawa and Takhini River (<https://yukon.ca/en/news/boil-water-advisory-residents-army-beach-and-south-mcclintock-private-wells-or-underground>click here<https://yukon.ca/en/news/boil-water-advisory-residents-southern-lakes-lake-laberge-kusawa-lake-and-takhini-river-areas>)
The attached graphs show the lake levels of Bennett, Tagish, Marsh and Laberge over the past 20 years based on Government of Canada hydrometric data. Peak lake levels are typically reached in August. The 2007 flood year is indicated in purple and the average is shown in red. 2021 is shown as the dashed light blue line. I have added the full-supply and low-supply levels in yellow (please note that the Gov Canada hydro data uses relative elevations; I have adjusted the levels by their suggested datum conversions).
If you know of anyone else that would like to receive this update, please let me know. And if you have any questions / information about the flood response, please send them to me or This email address is being protected from spambots. You need JavaScript enabled to view it.
Best,
John
pdf Southern Lakes flood briefing July 13 2021 (249 KB)
