A process for increasing the water discharge of a drilled well, previously used for water delivery, and having decreased water discharge, which comprises the following steps:
- (a) introducing into a filter section of the well a weak acid whose dissociation constant is less than K.sub.D =10.sup.-3 for a period of 10 to 48 hours under pressure;
- (b) flushing the filter section of the well by means of a scavenging pump to remove the weak acid;
- (c) introducing into the filter section a basic solution of sodium bicarbonate or sodium hypochlorite or mixtures thereof for a period of 1 to 36 hours;
- and
- (d) again, flushing the filter section of the well by means of a scavenging pump to remove the basic solution.