At left is the Arts Building, and the Richardson Building is at right.
Downer Group is the main build contractor for the latest phase of the work, between Union St and the Leith St footbridge.
The Leith channel wall, at left, is being raised by 60cm.
Council engineering, hazards and science director Dr Gavin Palmer said the red digger (at right) was undertaking work that will result in channel-widening.
Asbestos-containing material had previously been discovered, where it had been buried further up the same bank.
The removal of that material was ''complete, or substantially complete'', having been excavated and removed from the site.
Adverse weather in April and the asbestos discovery had contributed to a later completion time.
The timeline for completion of the latest phase was being revised by the contractor.
''We want the works to be completed as soon as practicable whilst doing so safely,'' Dr Palmer said.