Bass holing up under grass mats is usually something they do after a good front moves through and usually once they've begun the spawning sequence. Earlier last week was a good example of such a front but I'm not sure if they would've started spawing yet where you're fishing. If they haven't you'll probably find more fish in deeper water (not sure that's possible in the canals?). Picture this: The fish is on bed and a big front moves through. Since the urge to spawn has been set in that fish's mind they're not going to move out very far if they don't have to. This is when they hole up in the nearest clump of thickness with a prime target being matted vegetation on top of the water. Now look at it the opposite way. If they're not spawning their first inclination is to always move to deeper water so flipping grass mats doesn't make much sense. But again, it depends on the body of water you're fishing.
Looking at your narrow canal I'd focus my attempts in the middle where the deepest water is most likely to be. There also may be a spot on the canal that has some change in contour. It may be a turn, a wider section, a spot with deeper water (even if only a foot), or anything that gives the bass something else to relate to. If the entire thing is, indeed, matted over with vegetation you may have few other options besides flipping.
Technique-wise: I find that nearly all my bites come on the fall and for this reason I try to use as light a weight as I can get away with. Sometimes you need that 1oz weight but other times you can get away with something much lighter. This isn't usually the case when punching through grass mats...you need weight. In cold or post-front conditions it may take a couple hops off the bottom and allowing the bait to sit still for a couple seconds to entice a strike.