The invention relates to a method and a system for engine water injection. Methods and systems are provided for adjusting water injection at distinct locations of an engine based on a total water injection error determined from an output of an exhaust oxygen sensor. The method may include injecting water at distinct locations based on a cooling demand and a dilution demand. Further, the method mayinclude distributing the total injection error to respective water injectors, as well as adjusting engine operating parameters, to provide desired engine cooling and dilution.