Board, which has power delegated to it by the Council. The Selwyn district is within the Canterbury Region so Canterbury Regional Council has responsibilities for regional planning, and water, air, discharge and river bed resource consents. The Selwyn district has powers delegated to it by the Government of New Zealand, and carries out its duties with regard to laws such as the Local Government Act 2002 and the Resource Management Act 1991. In national politics, Selwyn is represented in the Selwyn electorate. Nicola Grigg of the National Party is the incumbent MP. Geography The Selwyn District lies in central Canterbury, and occupies a central position in the South Island. Boundaries: On the Canterbury Plains, the Waimakariri River forms the northern boundary; in the hill country the border with the Hurunui District is more arbitrary. The eastern boundary comprises (from north to south) the city of Christchurch, Banks Peninsula, and the South Pacific Ocean. The southern boundary is the Rakaia River, beyond which lies Ashburton District. The western boundary is the main divide of the Southern Alps. Geographical features: Selwyn District contains within it two distinct regions: the plains and the high country. The plains, where most of the population lives and the majority of activity takes place, form an expanse of low-lying, flat, and comparatively dry grassland. The extreme south-east is dominated by Lake Ellesmere / Te Waihora, an expanse of water surrounded by marshes, formed by the out-flow of the Selwyn River / Waikirikiri. The tributaries of the Selwyn River include the Waianiwaniwa River, the Hororata River and the Hawkins River. The high country is a sparsely-populated region, mainly consisting of hill and mountain ranges and narrow river valleys. Most of the high country is grassland, including some tussocklands; areas of beech forest remain within the Craigieburn Forest Park and the Arthur's Pass National Park. Climate: The plains have a temperate climate, characterised by warm, dry summers and cool winters. The Southern Alps are responsible for the relatively low rainfall, and also lead to a foehn wind, the "Canterbury Nor'Wester". This strong, hot and dry wind is most common in spring and summer, and on occasion reaches damage-causing strength. In the mountain country of the Southern Alps, conditions are much colder and wetter. Demographics Selwyn District covers and had an estimated population of as of with a population density of people per km2. Selwyn District had a population of