He emigrated to South Africa in autumn 1888, when appointed Durban's harbour engineer, his orders were to remove a sandbar obstructing shipping at the harbour entrance, forcing passengers and cargo to be moved by lighter. Methven's plans to get rid of the bar by extending the North Pier and using the scouring action of tidal currents, brought him into conflict with a prominent lawyer, Attorney General and politician, Harry Escombe, who wanted to rely on dredging alone. Consequently, Methven was dismissed on 11 July 1894. This led to a tremendous uproar ending in Escombe's resignation. Much later, in 1918, the South African government granted him £500 in recognition of his services with development of the harbour. His other recommendation that the Umhlatuzi Lagoon be developed as a second harbour for Natal, was also followed in the 1970s and is now known as Richards Bay.
