Big cities in Turkey have a single metropolitan municipality each. Below the metropolitan municipality each district also has its own local mayor and local parlament. They have a duty sharing system.
For example water and public transportation is responsibilty of the metropolitan municipality. Collecting property taxes is responsibility of the smaller local municipalities etc.
1) this is a huge bill, but it is relevant that it is a bill for a large city council (as opposed to a village facing the same bill)
2) they are big enough they should not really be considered as too small to afford good counsel on how to do this sort of project properly