I've paddled in the Ala Wai since I was a kid,  It's gotten progressively worse in terms of pollution, run off and homeless trash that flows down into the ocean where many of us surf Bowls.  When the sewage spill occurred the entire ocean out past the 2nd channel buoy stunk and the water was green/brown.  What is being talked about is needed, but in addition, the flow of water was supposed to have an inlet/outlet at the Kapahulu groin so that the canal would actually have movement with the tides.  However, because Waikiki is the tourist mecca that it is, it's doubtful this connection would ever happen as it would probably make the Kapahulu end more like the Ala Moana end.  Run off from the mountains is inevitable.  Silt, mud and debris need to be dredged regularly to keep the canal deep enough particularly where Manoa stream empties into it.  If there is a need for a TAT tax increase, this would be it.  Hotels won't complain when it benefits themselves.