Credit unions are turning away cash and asking members to reduce their savings balances to as low as €25,000.
High numbers of members are saving with credit unions rather than banks, but not enough are taking out loans.
An additional €800m was saved in the State's 286 credit unions last year, taking the total for the three million members to €13.3bn.
For every €100 in savings, €10 has to be put into the reserves. But the money that goes into the reserves comes from profits made on loans.
Rathfarnham Credit Union asked its members to reduce their saving balances to €50,000 last year and is considering lowering that cap to just €25,000 this year.
Capital Credit Union, which emerged from the merger of Dundrum and Sandymount in Dublin, is restricting new savings to €30,000 per member.
Existing members with savings above this amount will not be asked to reduce their balance.
St Anthony's and Claddagh Credit Union in Galway is imposing a cap of €70,000 per member for new savings.
There was fury when the Central Bank imposed a limit of €100,000 in savings per member two years ago.
The Central Bank acknowledged that credit unions are restricted on where they can invest surplus cash.
The options mainly consist of safe but low-yielding investments, such as bonds and bank deposits.