Engineers were today carrying out emergency repairs after water swamped Cleveden Road in the West End.
The 12in main burst yesterday afternoon - but staff at Scottish
Water said the repairs were "more complex" than they first thought because of other utilities nearby.
The road was reduced from two lanes to one in each direction, while Great Western Road was partially blocked at the Hyndland Road junction while engineers worked to repair the leak.
The closure caused disruption to motorists last night and this morning. No local water supplies were affected.
A Scottish Water spokesman apologised to road users, but could not say when the road would re-open fully.