Thanks for your thoughtful response, Diane.
Unlike the Broken Group, this is not a managed recreation area, so bookings/fees/permits/maintenance/monitoring etc are unavailable. Instead, conditions at the site depend mostly on user behaviour, which seems to be substandard.
Education, improvements in paddler etiquette and adoption of the BCMT Code of Conduct might take too long to achieve results. Finding funds to provide a composting toilet could create a worse overcrowding issue than we already have, so maybe the short-term answer is for the Conservancy manager and local FN to declare that it is for day use only, with no camping permitted. (Enforcement of such a rule would be another matter!)
One wonders however, where all those displaced, disrespectful paddlers will camp next?
On a more optimistic note, one take some comfort in seeing major changes over time in other anti-social behaviours such as smoking and drinking and driving.