High Quality Content by WIKIPEDIA articles! Waltham is an inner suburb of Christchurch, New Zealand, located two kilometres southeast of the city centre. State Highway 73, part of Christchurch`s ring road system, runs through the suburb, as does the Heathcote River and the Christchurch - Lyttelton rail corridor. The Christchurch gasworks was located at the inner boundary of Waltham until its closure ca. 1980.