The Government of Yukon Water Resources Branch has released the April 1 Yukon Snow Survey Bulletin and Water Supply Forecast. The snow survey found that the southern and eastern parts of the territory have close to average snowpack levels while the central and northern portions of the territory have above-average snowpack.
While the snowpack is above average in some parts of the territory, in contrast to the previous two years, the snowpack is much closer to normal. It is also lower than the 2020 snowpack in almost all basins.
The Upper Yukon Basin rose slightly above average, while the Alsek, Teslin, Liard, Stewart and Pelly Rivers basin-wide snow water equivalents are estimated to be close to average. The Alsek basin is estimated to be below average. The Central Yukon and Lower Yukon (Dawson area), White, Porcupine and Peel basins are all above average with the most concentrated area of high snowpack centring around the lower White and adjacent areas of the Lower Yukon basins.
Record and near-record high baseflows in many systems indicate well above-average groundwater levels in many areas of the territory. This, combined with above-average snowpack, will lead to higher than average freshet volumes in Yukon lakes and rivers this spring and potentially above-average peak water levels in many areas. High groundwater levels combined with above-average snowpack also increases the risk of slope failures and localized runoff flooding in low-lying areas.
The snow survey shows that there will be average- to slightly-above average flood potential for spring breakup and spring freshet in most of the territory. Areas with above-average flood potential include the central and lower Yukon River basins and to a lesser extent the Peel and Porcupine River basins. However, the elevated risk is mostly in small- to medium-sized rivers with lower risk on larger rivers, including the Yukon River.
High snowpack is one of several risk factors which influence flood potential during the spring breakup and snowmelt period. Spring weather, the timing and progression of snowmelt, as well as spring precipitation events, are also important drivers of flooding regardless of snowpack levels.
Every March, April and May the Government of Yukon conducts Yukon-wide snow surveys to help forecast water levels and flow conditions across the territory.
The April 1 snow survey typically represents peak snowpack in most parts of the territory.
The Snow Survey Bulletin and Water Supply Forecasts provide a summary of winter meteorological and hydrological conditions for major Yukon watersheds.
The bulletin provides long-term snowpack averages, monthly data, and current snow depth and snow water equivalent observations for 52 locations in the Yukon, and five locations in the neighbouring areas of British Columbia and Alaska.
Snow water equivalent is the amount of water released from the snowpack when it melts.
Spring freshet is when rivers and lakes rise and peak in response to spring snowmelt. The freshet can last several weeks.
The last snowpack survey for 2023 will be conducted on May 1, with the findings publicly released by mid-May.
Jake Wilson
Communications Analyst, Environment
867-334-8390
jake.wilson@yukon.ca