This file contains chemical data for 25 streams in New Zealand across an acid mine drainage gradient. pH and conductivity were recorded in the field using standard meters (YSI 550A & YSI 63). Element concentrations were estimated using ICPMS analysis of a filtered (pore size = 0.45 um) water sample collected in the field. site = site name. cond = specific conductivity (microsiemens per centimeter). Elemental concentrations are reported in micrograms per liter.