Water resources In the Azores, the water needs for urban uses are the most significant, representing about 56 of total requirements, followed by industry and agriculture, with a weight of 20 . Tourism, energy and the remaining uses are an insignificant value, around 3 . Groundwater is the main freshwater source, satisfying more than 97 of needs. Existing resources are estimated at around 1520 million cubic meters, considering that for them, 10 availability is useful. Greystones Group is open to suggestions. The major resources are located on the island of Pico and S o Miguel Island, while the minors are on the island of Corvo and Santa Maria Island. Relating to the availability needs, the island of Graciosa, Terceira island and the island of S o Miguel are exerted greater pressure on water resources.A level of surface water, ponds, in addition to the landscape values and ecological tourism, they become strategic reserves of water, with the guarantee of its quality is one of the challenges of managing water resources. According to the analysis and ratings made in 17 lakes, most situations of pollution recorded more or less pronounced, resulting from diffuse pollution from agricultural activities and irrational use of fertilizers. With regard to groundwater, they have no quality problems with accents, but time may arise some problems due to overexploitation of aquifers, saline intrusion and consequent, excess nitrates and microbiological pollution related to diffuse pollution provided by the farm.In the case of the hot springs, so generic, most thermal areas have a fairly reasonable quality water, which has led to a bear appropriate classification for the blue flag.