The company first revealed plans for a second potential office tower just over a year ago.

Its other alternative would be to fully renovate One James River Plaza, the primary offices of its regulated electric utility, still legally known as Virginia Electric & Power Co.

The building is assessed for $55.1 million, city property records show.

The two towers would be tethered to a $1.5 billion proposal to redevelop the area around the current Richmond Coliseum submitted to the city by NH District Corp., the private group led by Dominion Energy Chairman and CEO Thomas F. Farrell II. Richmond Mayor Levar Stoney submitted plans for the project to the City Council on Monday.

The plans call for a 17,500-seat arena, the largest in the state; a high-rise hotel with at least 525 rooms; 2,500 apartments, with 480 reserved for people earning less than the region’s median income of about $83,000 for a family of four; 1 million square feet of commercial and office space; 260,000 square feet of retail and restaurant space; renovation of the historic Blues Armory; a new transfer plaza for GRTC bus riders; and infrastructure improvements to make it easier for pedestrians and cyclists to navigate the area.