City Services acting executive director Fleur Flanery said the trees, in the area from Antill Street to Macarthur Avenue, would be removed from Monday, with the likelihood that a similar number would be removed in the section from Macarthur Avenue south to Alinga Street.

The Canberra Metro light rail consortium is organising and paying for the removal of any trees in the median, with the government removing any trees that need to come down on the Northbourne verge.

The consortium will ultimately remove and replace all 358 trees between Alinga and Antill streets - but while the mass tree removals were scheduled to start in October, they have been pushed back, with no starting date yet.

Meantime, Ms Flanery said the recent wet and windy weather had made the removal of up to 40 trees necessary now.

The ones to be removed from Monday are river peppermints. They were planted between 1983 and 1986 and were the third generation of trees planted in the median strip of Northbourne Avenue.

"Many of these trees have been assessed as being on a significant lean or having considerable structural damage and in the storm event last Tuesday we did see three trees on the corridor fall," she said.

"It is important for the ongoing safety not only of motorists, pedestrians and other road users but also the construction workers from Canberra Metro who are working in the median and verges of the Northbourne Avenue corridor, that trees at risk are safely removed."

Under the contract with the private Canberra Metro consortium that is building the 12km light rail track, the consortium is responsible for removing and replacing trees on teh median on Northbourne Avenue, Flemington Road and the Federal Highway.

The trees were to be removed from October, with the inner row to go first, and the outer row to be removed by mid-2017. But work is yet to begin.

A directorate spokeswoman said there were about 700 trees remaining in the corridor - on the verge and median. Trees in the median would all be removed and replaced. Some on the verges would be removed, with some replanting.

The median trees are to be replaced with 4-metre high trees that are expected to "approach maturity" – 10 to 20 metres high – within 10 or 15 years of planting. The trees are being grown in Gippsland and are expected to arrive at Yarralumla Nursery soon to complete their growth.

Ms Flanery said this week's removals would be done outside peak hours where possible.

The latest move follows the removal of 42 trees from the same area - between Alinga Street and Antill Street - in April, at a cost of $32,000.