Except as provided in section 8-2-3 of this chapter, no person shall obstruct, encroach upon, encumber or otherwise interfere with any public grounds, or streets, or easements held by the city for street or utility purposes, by putting thereon any curbing, paving, fences, buildings, markers, posts, rocks, stones, or other structures, or depositing thereon snow, debris, or any other matter. The prohibition herein stated shall apply as to any easement to the entire width or extent thereof, and not just to the portion which may from time to time be in public use for travel or other purposes. (1981 Code 702 § 1)