Millions of pounds will need to be invested in Northumberland if RAF Boulmer closes, according to the county council.
The future of the site is being considered by the Government as part of its Strategic Defence Review.
Northumberland County Council has now produced a report, warning of the consequences of closing the site which employs 800 staff.
The RAF is the biggest employer in the Alnwick and Amble areas.
The RAF has signalled that the base is one of four in the UK being looked at in a review of combat support units.
Bill Brooks, deputy leader of the council, said the base had a massive input to the local economy in what was otherwise a largely isolated area.
He said: "It is quite huge - £18m in wages and salaries per year goes into the local economy.
"To remove that in one swoop will have a devastating effect on the area and cause huge damage to the fabric of the community and the services they provide."
Long-term effects could also include a threat to the future of Longhoughton Village School, which draws around 75% of its pupils from families on the base.
Northumberland County Council and Alnwick District Council have urged the RAF to consider the economic effects before reaching a final decision.