The organisation, which represents council transport chiefs, said the mitigation measures to address environmental impacts of the scheme must not be underestimated and HS2 had to learn from previous schemes including HS1.
One must seek the consent of both the person involved and the representing council.
The union that represents council social workers said Ms Olley had been made a scapegoat in the case.
"80% of a market rent for a two-bedroom house is over £700 a month," said John Marais, who represents council tenants.
Two of the other main unions representing council workers have not ruled out calling for the pay offer to be revisited.
The Local Government Association, which represents councils, said the figures were of great concern.
The Local Government Association LGAA), representing councils, says the system means England loses out by £4.1bn a year.
The Local Government Association, representing councils, accused the government of burying its head in the sand.
The Local Government Association, which represents councils in England, issued a report declaring that London would be "worst hit in a recession".
Adass and the Local Government Association, representing councils, have been warning of a £4.3bn funding gap in social care by 2020.
