R.I. Gen. Laws § 1-3-16

In granting any permit or variance under §§ 1-3-14 — 1-3-16, the administrative agency or board of appeals may, if it deems the action advisable to effectuate the purposes of this chapter and reasonable in the circumstances, condition the permit or variance as to require the owner of the structure or tree in question to permit the political subdivision, at its own expense, to install, operate, and maintain suitable obstruction markers and obstruction lights thereon.