Abstract: Process for increasing the water discharge of water delivering drilled wells, which can be characterized in that into the filter section of the well weak acids with a dissociation constant being less than K.sub.d =10.sup.-3 are introduced. After a dwelling period of longer duration, expediently 10 to 48 hours, as well as compressing, flushing is performed by means of a scavenging pump. Thereafter the solution of sodium bicarbonate and/or sodium hypochlorite is introduced into the filter section. After a longer dwelling period, expediently one to thirty-six hours, flushing is performed by means of the scavenging pump. As weak acids with a dissociation constant being less than K.sub.d =10.sup.-3 acetic acid, tartaric acid, citric acid, metaboric and/or tetraboric acid is used.