You pay fees because your municipal authorities or the water board do something for you individually. For example, if you apply for a permit. It is not relevant whether or not your municipal authorities actually grant the permit. Your municipal authorities or water board already incurs a cost just to process your application. The municipal authorities or the water board pay for these costs using the municipal fees.
The person or entity for which the municipal authorities perform the service. For example the applicant of a permit.
There are several rates. The amount of the rate depends on what the municipality or water board does for you
