Impact Fees; Provides requirements for coordination mechanisms that are required for certain agreements required as part of intergovernmental coordination element of comprehensive plan; requires that certain interlocal agreements use plan-based methodology; requires that demonstrated-need study use plan-based methodology; requires that certain capacity standards be specified in certain impact fee study; prohibits local governments, school districts, & special districts from including certain deductions in certain impact fee increases & from increasing impact fee rates beyond certain phase-in limitations by more than specified percentage; provides that prevailing petitioner is entitled to impact fee overpayment refund, with interest.