Devon County Council has said about 900 jobs will have to go because of government spending cuts.
The council has calculated it is losing far more than the 2% originally presented by Communities Secretary Eric Pickles on Monday.
It said it is looking at a 12% funding cut, meaning it will have £26m less to play with.
Although the council has not ruled out redundancies, it is hoping to shed posts through its job freeze programme.
This works by not filling posts after non-frontline staff have left.
Cuts will also affect senior management posts, with the council planning to reduce those costs by 25%.
Children and young people's services will be cut by 13%, although the council said safeguarding children and children in care budgets will not be hit.
Devon Youth Parliament member Aydan Greatrix said much as he hated the stereotype, cutting youth services could lead to some young people having nothing to contribute to society if they had "nothing better to do than hang about the streets causing trouble".
The council said none of its 50 libraries would close, but some branches could have opening hours reduced.
The budget for environment and economy services, including waste, roads and transport, will be cut by 11% and the adult services budget, which includes care of the elderly, is facing a 5% reduction.
Council leader John Hart said it was "inevitable" that services would suffer.
"I am not going to try to pull the wool over anyone's eyes - these spending cuts are going to hurt," he said.
"By the end of this process Devon County Council will not be doing anywhere near as much as it has in the past.
"Having said that we are still determined to do our utmost to protect the most vulnerable people in our society whether they are young or old."
Karen Williams, from the public service union Unison, described the job cuts as "absolutely dreadful".
"It's really quite devastating - not only to our members, but to the community at large," she told BBC News.
She said nearly 800 jobs had already been saved through the council's recruitment freeze over the past 12 months.
"So altogether, we're looking at 1,700 jobs going at Devon County Council over a three-year period which is an incredible number," she said.
Ms Williams said the cuts being "forced" on local authorities by central government would directly affect local communities.
"We really think its unacceptable that councils are having to make these dreadful decisions," she said.
"The reality is these cuts are being made too fast and the front loading of them is too heavy and it is going to throw council services into some degree of chaos."
The proposed cuts will be presented at a cabinet meeting later, but the budget will not be finalised until February.