1. The payment of all pension benefits, refunds and other benefits or expenses pursuant to the provisions of sections 169.410 to 169.540 and all expenses in connection with the administration and operation of the retirement system are hereby made obligations chargeable against the assets of the retirement system and not of the employers, and the assets of the retirement system shall not be diverted or used for any purpose other than the payment of such obligations.

2. No alteration, amendment or repeal of sections 169.410 to 169.540 shall be deemed to affect the rights of members of any retirement system established thereunder with reference to deposits previously made, or to reduce any accrued or potential benefits to those who are members at the time when such alterations, amendments, or repeal becomes effective or to reduce the amount of any pension benefit then payable.