Mr Alder said the speed at which bridge spans were blocked was “frightening” and accused the council of assuming the structures were strong enough to resist damage.
River blockages were impacting the Gisborne flats by causing flooding, he said.
“It takes a two-hour trip with the mayor to suddenly realise that we do have a drainage problem out there and that spending more than $100,000 a year might solve it.”
Councillor Andy Cranston and Mayor Rehette Stoltz called for a point of order, with the latter saying she did not like people making assumptions on her behalf.
Independent chair Bruce Robertson appreciated there was a strong level of feeling around the issue but cautioned Mr Alder on what could be considered a “slighting” of the mayor. He pointed out the paper on the table — the council’s strategic risk management report — was general, requiring an openness as to whether what it discussed was accurate.
Mr Alder apologised, saying it was not his intention to cause offence.
Prior to raising concerns about the state of the city’s rivers at Tuesday’s meeting, Mr Alder also took issue with the council’s risk assessment of procurement, or staffing levels.
The council had labelled its level as “moderate” which was an improvement from a “major” tag earlier in the year.
Council internal partnerships directorJames Baty said a contributing factor to the level of risk in procurement was an increase in people moving out of the region or overseas.
“It’s going to take some time for the labour market to return to what it was before Covid.”
Areas identified as being at a level of serious risk included finance, the natural environment, asset management and recovery.
Tuesday’s meeting was not the first time Mr Alder has made a public apology.
In March, he apologised after being challenged for his use of the term Ngāti Pākehā in a council meeting.