Here is 100 years of Sylvan Lake water level data:
Most of the data up to 2014 are in the Environment Canada HYDAT database that can now only be accessed offline with great difficulty. The whole HYDAT database must be downloaded then searched using Microsoft Access as a viewer.
The 2010-2019 data are from other sources in our SLWSS library. The previous Environment Canada online interface no longer works so many of the links in https://slwss.org are broken, useless, and cannot be restored.
The alternative that does work during open water seasons is the Alberta https://rivers.alberta.ca. To see Sylvan Lake, zoom in on the map until you can view Central Alberta, then click on the Sylvan Lake pin and open the data or graphic of interest. Note that a mobile app is available.