Malcolm Green, Glasgow's education convener, told the committee: "Provision will not be made elsewhere and people will not get the service they are used to having."
Chris Mason, the Liberal Democrat spokesman, described the loss of the centres as "tragic". The council had been "left with the ruins" of an outdoor education system because of Government cuts.
The council, if it beats off the challenge from Argyll and Bute, wants to make Blairvadach available during the school year only to city schools. Two-thirds of these visitors would be primary pupils. Weekends and non-school weeks would be targeted at other groups to raise income. Conceived as a sailing centre, Blairvadach was built 25 years ago and can cater for up to 68 young people.
Caol Ruadh would continue to focus on city children with special educational needs. It is a large mansion, can take up to 36 pupils and is often used for environmental and field studies, orienteering and gentle hill-walking.
Glasgow is keen to expand the use of Caol Ruadh by encouraging bookings from specialist groups outwith the school year.