Whenever the tract to be subdivided is of such unusual size or shape or is surrounded by such development or unusual conditions that the strict application of the requirements contained in these regulations would unnecessarily result in substantial hardship or injustice, the city council, after report by the planning and zoning commission and the director of public works may vary or modify such requirements such that the subdivider may develop his property in a reasonable manner, but so that, at the same time, the public welfare and interests of the city and surrounding area are protected and the general intent and spirit of these regulations preserved. (2005 Code)