It is 31k without the loop around Duncan. The actual TCT route for this leg is 28.2k needing a connector to Duncan City Center. This is a highly developed enjoyable trail that goes through a major bog and heritage sites. Close to town is the Cowichan Commons Mall, a good place to park. However, it really worthwhile to go into Duncan Centre to appreciate both Native and local heritage. The loop around town is an opportunity to follow a series of greenways that surrounds Duncan. There is more description of the sites on the Trails BC Website that describes the full Cowichan Valley Loop.
Duncan to Lake Cowichan on the TCT t57