In the Spanish region of Catalonia the industrial sector sensibly lobbied for the privatization of municipality-produced water services in the period 1996 – 2002. This paper analyzes the extent to which this result is consequent with observed measures of cross-subsidies in favor of residential consumers. I run a treatment-effects regression on a sample of 133 municipalities in 2000 and 2001. Recent privatization has a positive effect on the weight that the local regulator attaches to industrial users’ welfare when deciding water tariffs. I conclude that an increase of industrial customers’ group size has a twofold effect on the cross-subsidy in favor of residential customers: a direct positive substitution effect and an indirect negative political support effect through lobbying for service privatization.