The Directive defines the category "lake" as "a body of quiet superficial inland water " (Article 2) and specifies a lower limit of 0.5 km2 when establishing its rates (Annex II). At the level of Spain and based on preliminary CEDEX criteria, all those lakes with an area of ​​more than 50 ha (0.5 km2) or all those with an area of ​​more than 8 ha and exceeding 3 m in depth are included as bodies of water. The Agency through two agreements with research centers has proposed as bodies of water that could be assimilated to the category of lakes: 1 - Lakes and ponds of more than 0.5 ha of surface located at altitudes above 800 m and lakes below this level with a depth of more than 6 m (agreement with the CEAB-CSIC; Agency, 2003d). 2 - Wetlands located at altitudes below 800 and with a depth of less than 6 m (agreement with the UdG; Agency, 2004d). Also included in this category are the reservoirs of the inland basins of Catalonia.