Lock filled by debris

I'm still not clear what you question is. Up there you asked "How to tag the debris that filled the lock" and wrote something about a way being blocked and water not so. But I rather get the feeling you would like to get some guidance on how to tag the lock in its entirety.

A normal lock is tagged by e.g. waterway=canal + lock=yes. On the aerial image it looks like there is no canal anymore (it's been filled). Thus, I would remove the waterway altogether. Instead map the outline of the old lock and tag it with man_made=lock. This is consistent with bridge tagging where you put bridge=yes on the road and man_made=bridge on the actual structure. You could also use man_made=lock_gate to map the gates. Both tags have been used a couple of times. If you want additionally tag the area inside with surface=debris or an extra area with landcover=debris.

Alternatively, you could use abondoned:waterway=canal + lock=yes and abondoned:waterway=lock_gate at the nodes where the old gates are.

The current tagging (disused:waterway=canal + waterway=lock on the way of the canal and barrier=debris on the outline of the lock) is wrong in my opinion. For one the simultaneous use of disused:waterway and waterway seems wrong and waterway=lock is not the standard way of tagging locks. Additionally, I don't like barrier=debris. You probably think of a barrier against water but I think the usual OSM meaning of barrier is against some sort of traffic. Barriers against water are tagged e.g. as waterway=dam/weir/lock_gate.