Money derived from assessments levied under this Chapter and from interest earned on that money shall be spent only for the economic improvements and for the cost of City administration of the Economic Improvement District described in the final Economic Improvement Plan. Subject to the requirements of any labor agreements to which the City is a party and to any applicable requirements of state law, the Council in its discretion may authorize an agreement or agreements with the advisory committee appointed under Section 3.122.050 D for the committee to provide all or part of the economic improvements described in the final economic improvement plan.