(a) Units agreeing to an undertaking may establish a joint agency charged with any or all of the responsibility for the undertaking. The units may confer on the joint agency any power, duty, right, or function needed for the execution of the undertaking, except that legal title to all real property necessary to the undertaking shall be held by the participating units individually, or jointly as tenants in common, in such manner and proportion as they may determine.
(b) The participating units may appropriate funds to the joint agency on the basis of an annual budget recommended by the agency and submitted to the governing board of each unit for approval.