Lake Ellesmere Lake Ellesmere Lake Ellesmere is located in the Canterbury region of the South Island of New Zealand . It is a broad , shallow lake located directly to the west of Banks Peninsula , separated from the Pacific Ocean by a long narrow strip of land called Kaitorete Spit . The lake covers an area of 265 km² , and is the largest lake in the alluvial fan of the Canterbury Plains . The rarely used Māori name is Waihora , meaning spreading waters ( compare Lake Waihola ) . The main river that feeds the lake is the Selwyn .  This Canterbury , New Zealand -related geography article is a stub . You can help Wikipedia by expanding it . Coordinates : 43°48′S 172°25′E Categories : Canterbury , New Zealand geography stubs | Lakes of New Zealand | Canterbury , New Zealand 43 48 S 172 25 E region : NZ_type : waterbody 