Thetis Lake Park offers easy and pleasant trail running only a 20 minute drive from downtown Victoria. The main trail is a 5 km loop around Lower and Upper Thetis Lake, staying close to the lakes, and is relatively flat and not technical. There are also several offshoot trails, which are narrower and more rugged. See this link for a more detailed description. Great swimming post-run!
Add-Ons: Several additional trails and parks in the area: Stewart Mountain, Francis/King and Gowlland Tod.