Isopieze I aquifer of March 2013 (altitude above sea level - 5m isoline spacing) obtained from processing in a GIS environment of the precise piezometric data of the Environmental Information System. The Province of Milan has periodically developed a cartography of the piezometries and the subjacent of the superficial aquifer according to the representative methodology adopted since 2005. Technical data: Working scale: 1:10,000 Coordinate system: Gauss-Boaga (Western zone) - Cylindrical projection Gaussian conformal transverse - Reference ellipsoid: international Hayford ellipsoid - Rome '40. Type of vector data (shapefile): Polyline Geographic coverage: Administrative area of the Province of Milan (North-West X: 1.477.012 Y: 5.065.677 South - East