Rolls in some areas are set to drop by a quarter, according to unpublished projections shown to a private meeting of the council's budget working group.
Primary numbers will fall by 13 per cent and secondary by 21 per cent. The most seriously affected areas are Sutherland and Badenoch and Strathspey.
Only the Inverness city area is expected to show a rise, of up to 5 per cent.
The council projects a saving of pound;4.45 million in staffing, equivalent to 116 full-time posts. More management time in primaries will only create 45 posts.
More primary rolls will be down to single figures while there will a large number below 20. Farr High in Sutherland and Kilchuimen Academy in Fort Augustus - could be under threat in the secondary sector. Both will have around 40 pupils.