being dangerous for swimmers due to rips and large swells. Surf Life Saving Clubs patrol designated areas of the four most popular beaches during the summer months. Piha Surf Life Saving Club is the oldest of these, being founded in 1934. On 11 January 2010, the Auckland Regional Council opened the Hillary Trail, a 77 km trail running roughly south–north from the Arataki Visitor Centre to Muriwai through the Waitākere Ranges, named in honour of the New Zealand mountaineer Sir Edmund Hillary. The Hilary Trail is regarded as one of or maybe the best multi day hike in the north of the country. Reservoirs Five reservoirs within the ranges supply water to the Auckland region, including the Waitākere Reservoir and the Lower Nihotupu Reservoir. Combined, the reservoirs supply approximately 26% of Auckland's potable water demand. The ranges receive an average of over 2,000 mm (78.75 inches) of rainfall annually while the corresponding rate in the city is less than half that. As weather systems approach across the Tasman Sea, their path is blocked by the ranges causing a small uplift sufficient to trigger orographic rainfall. Fauna The area is home to kauri snails, glowworms and native long-tailed bats. Long-tailed and short-tailed bats are New Zealand's only native land-based mammals. At the northern end of the ranges, Otakamiro Point is the site of one of New Zealand's few mainland gannet breeding colonies. In the bush are many indigenous invertebrates, including kauri snail, wētā and oviparous velvet worms with 14 pairs of legs, and ovoviviparous species of 15 and 16 pairs of legs in the genus Peripatoides. The Ark in the Park conservation initiative, a partnership between Forest and Bird and the Auckland Council, is working to reintroduce some of the species made extinct in the Cascades Kauri Park section of the ranges. The project was started in 2003 and now covers . Demographics The statistical areas making up Waitākere Ranges, which include the populated areas of Huia and Karekare but not Piha or Te Henga / Bethells Beach, cover and had an estimated population of as of with a population density of people per km2. Waitākere Ranges had a population of 2,385 at the 2018 New Zealand census, an increase of 234 people (10.9%) since the 2013 census, and an increase of 348 people (17.1%) since the 2006 census. There were 873 households, comprising 1,206 males and 1,179 females, giving a