Longden Road in Shrewsbury has been shut since the beginning of last week for the repairs, but workers discovered a void in the ground, meaning work is taking longer to complete than initially expected.
The collapsed pipes are near the Kingsland Road junction. Shropshire Council had expected the work to be finished by last Friday before the void was discovered.
A spokesman said: "Severn Trent had operatives working over the weekend and they managed to repair the one collapsed pipe yesterday.
"Today they were installing further shoring equipment as they were having dig down even further in order to repair the second collapsed pipe.
"Due to the void discovered the reinstatement will take longer to complete than a standard reinstatement, due to the amount of material which will have to be imported to site. So, with these further complications, Severn Trent expect to be on site until at least Friday."