Permits and approvals are generally required for most land disturbing activities. As defined by the Porter County Unified Development Ordinance (UDO), a land disturbing activity is any activity that changes the surface of the land. This may include grading, scraping, or excavating of soil, placement of fill materials, paving, and construction of buildings or accessory structures, grubbing of vegetation, other activities that bare soil or rock, or activities that involve the diversion or piping of any natural or man-made watercourse.