Dear is it legal?
This is similar to other questions you have posted regarding a purported illegal structure in Oswego County, Town of Constantia (Bernhards Bay, New York).
The answers here cannot satisfy you. Hire an attorney nearby who might have a chance to help you.
The answer provided to you is in the nature of general information. The general proposition being that you should try to avoid a bad outcome if you can.
Unfortunately, you need more information to know the answer. It may be that the person empowered by the town to interpret their law made this determination. If that is the case, the code enforcer is probably right. However, depending on how the law is written, the person interpreting the law may have gone beyond their authority. And, although it is rare, sometimes staff members determine the way their law should be written and enforce that instead of the law they are stuck with. This they are no allowed to do.
I would investigate the matter further. Ask if there is an official interpretation of the provisions requiring the site plans. Also, you should contact an attorney in your area that practices in the area of local government law. They can probably help you get a fast, easy answer. Hope this helps.
This response does not constitute the giving of legal advice, establish an attorney-client relationship or a consultation. If you need legal advice, please seek out a lawyer for consultation as soon as possible as there may be statute of limitations issues that could bar your claims if they are not timely brought.
You may have a "political dispute" rather than a true legal dispute. You question suggests that you are unhappy with the enforcement of the law. This is generally an executive branch responsibility. The executive branch is elected and if it is not doing its job properly then that failure needs to be addressed in the next election. Often the judicial branch will refuse to become involved in these type of situations because it raises questions. That said some jurisdictions recognize extraordinary writs, which are a procedural device to ask the Court to force the person responsible to comply with the requirements of the law.