It sounds like you are confusing a state/county assessment with a private assessment. If it is all part of the HOA and the owner was on notice of such future development via the CC&R's and any plans on record, then you may not be able to claim this is an improper assessment. You should talk to a NC land use attorney to determine if there are any grounds upon which you can fight the assessment. You can also talk to a local HOA attorney to determine how a majority of owners may be able to stop such an assessment.
The statute reads "to the extent required by the Declaration" meaning that if the Declaration indicates this to be the case then the assessment shall only apply to the lots the receive the benefit - therefore you have to check the covenants/declaration to find your answer.
Mr. Portnoy is spot on. You need to review the Covenants for your HOA. This document should be on record with the Register of Deeds and may be available online depending on the county.
This answer is for information purposes only, and does not establish and attorney client relationship. James Faucher is licensed to practice law in North Carolina only. You should always contact a local attorney to get location specific answers about the law.
All of this will be dictated by your HOA agreement/ deed restrictions etc. I suggest that you start there. It is important to remember that HOA's can do a number of things that the government could not do. This is because it is presumed that you agreed to the terms of the HOA when you purchased your home.