Works of the Expo near the Almozara The Rivergate is a broad flood plain created by the Ebro River before entering the urban area of the capital, which was occupied by orchards supplying mainly the market Zaragoza. According to sources within the organization, the construction of the Expo 2008 to raise 5.5m bend the coat natural soil, for which 334,000 cubic meters will be used, to which we must add 140,000 m of concrete for the structure bear flags. The construction of the Expo 2008 in Rivergate has been questioned from various social groups that have emphasized the contradiction of the works and the location of the event with the theme of the sample itself concerning sustainability. In this sense, geologists recommend no building on floodplains as the Rivergate, which they say have a period of flooding of some 20 years.To solve this problem will be constructed levees, although some might not be enough long term. Keep in mind that the Ebro and its tributaries have many dams upstream in Zaragoza, so that the flow can usually be controlled. Furthermore, it will destroy about 120 acres of productive orchard and the expropriation of this land has cost the City billionaire who could not afford, so it was Ibercaja who bought the land and swapped the City for construction land in the estate Arcosur, also criticized from the Federation of Neighborhood Associations of Zaragoza for being anti-ecological to be too far from the city, in contravention of the criteria of social sustainability and economic and compact city. Moreover, for the Expo 2008 will be carried out other works such as a diversion dam on the Ebro folding to create a stable water layer of 4 km, criticized by scientists in limnology to alter the hydraulic regime of the Ebro RiverBecause of these works has been seriously affected the biodiversity of the river, as they have been removed due bivalve mollusks (naiads) native in a stretch of 8 km. In July 2005, technicians from the City of Zaragoza and firefighters withdrew 800 pieces of nymphs of the species Anodonta Cygne, Mancuso and potom Unio littoralis. Complaints about the noise level to be borne by neighboring construction sites (especially the weir and the flags on the bend) are constants, with allegations to local police almost daily. Also during the month of August 2007 jumped a public controversy by dredging that should be in the Ebro River to the navigable foreseen at the same sample and run by a private company. This project also brings with it the recess of the floor of the medieval stone bridge of the Aragonese capital and has performed with positioning against environmentalists, advocates of the historical and scientific community.The high cost of living (rising housing prices and inflation in the prices of the shops facing the Expo) while increasing the police presence is generating a tense debate in Zaragoza, mainly by social groups and unions outside the state who are opposed to living in a city where housing prices are so high, thus, they say, that Zaragoza is a paradise for speculators or Zaragoza in becoming a real police state. On the expo itself, at the time of his inauguration was not finished, details on the finish inside the compound as leaks, lifted floor tiles, a few blocks without end and without collecting building materials, lived with shabby surroundings, especially in the area of the park “Luis Bu uel”, opened at will.