Joined: 22 Aug 2021
Location: Sicamous, BC
|Posted: Sun Feb 20, 2022 2:08 pm Post subject: Early Runoff Forecast for 2005
|While it is still too early for reliable predictions, however, the current conditions allow a first outlook and tendency of the upcoming spring runoff for the Shuswap Lake watershed as follows:
Get ready to expect a higher peak level than the past few years.
The peak level for the Shuswap Lake depends mainly on the 3 major factors:
3. Lake level at the beginning of the runoff
The weather, of course, has to remain an unknown factor at this point. However, a cold spring, followed by a hot and sunny summer, has the potential to amplify the extend of the runoff through a shorter time span, leading to a faster level increase and a higher peak.
The snowpack is a given constant. The amount of water for the complete runoff is stored as snow in the mountains. A higher snowpack equals more lake inflow. Also, the higher the snowpack the more compressed are the snow layers towards the ground, resulting in a faster level increase towards the end of the runoff.
As an average, the Shuswap Lake will increase about 3 metres (9 ft.) from the lowest level to its peak. The chart below demonstrates the low/high level differences for the past few years. A normal snowpack will raise the lake level between 2.8 and 3.4 metres.
The snowpack for the Shuswap Lake watershed is currently classified as normal or slightly above normal.
The third factor, the lake level at the beginning of the runoff, is equally important for the yearly peak level of the Shuswap Lake. Under normal weather conditions and a normal snowpack, the peak level linear raises or falls with the given water level at the beginning of the runoff. The chart below compares the lake levels of 2003/04 to those of 2005.
As of today, the Shuswap Lake is at a start level similar to that of 1997 (flood year, highest peak since 1972). It is not expected that the lake level will drop significantly before the begin of the runoff sometimes in mid of March. Adding the level increase based on a normal snowpack to the current lake level gives reason for concerns regarding possible flooding, at least in the floodplain of the Shuswap Lake and some major streams.
This forecast is not intended to cause fear or worries about flooding. As mentioned at the top of this report, it is still too early for a definite outlook of the upcoming runoff. Please consider the charts provided here and form your own opinion.
For the property owners at the lake and in the floodplain:
be aware and return to this site frequently for updates, trends, and runoff conditions.
Bernhard Kramer, Webmaster