Last year city council engineers discovered there was a problem with the section of quay wall on the south side of the river between the Kingston and Tradeston Bridges.
Recent checks showed the problem has got worse and a decision was made to close a section of the riverside walkway.
The quay wall is owned by the 278 owners of the properties in the Waterfront development.
It is estimated the bill for repairing the damage is likely to be in excess of £1m.
In March last year, a 50 yard stretch of the walkway collapsed into the river on the north side of the Clyde, just west of the Kingston Bridge at Anderston Quay.
The new problem came to light when council experts checked the condition of other sections of the river's quay walls, many of which date back to the 1800s.
Were the quay wall to collapse, the bill to repair it could run in to millions of pounds.
The Waterfront properties are factored by Speirs Gumley, who have called in specialist engineers to assess the scale of the problem.
Lorraine MacDonald, a partner in Speirs Gumley, said: "We are working with the Waterfront owners' association and the city council to decide how to deal with this."
The city council is responsible for the riverside walkway, but not the quay wall on top of which it is built .
A council spokesman said: "Although the quay wall is privately owned, a public walkway has been closed by the council as a safety measure until the property manager informs us the wall has been repaired."
Although the council does own some sections of the Clyde's quay walls, others belong to private owners.
George Parsonage, of the Glasgow Humane Society, who patrols the river regularly in his rescue boat, said: "I hope the problem is not too bad but something will have to be done.
"The people who own the houses own the quay wall and if anything goes wrong with it they are responsible.
"In my opinion, if the quay wall is open to the public it should be maintained by public money."
Mr Parsonage said work on repairing the quay wall between the Clyde Arc and Elliot street on the north bank of the river is just being completed.