Groundwater Decoupling in Residential Water Use: (Illusory) Evidence from the Campania Region, Italy

Abstract As water scarcity expands and intensifies globally and internationally, a delinking of water use from growth will be essential to sustain economic expansion and ensure adequate well-being. The concept of decoupling, especially in its relative dimension, introduces many ambiguities because it does not have a direct and immediate connection with the ability of the environment to sustain, absorb or resist pressures of various kinds. In this article, we show the illusory evidence of relative groundwater decoupling observed at the residential level from 1981 to 2020 in the Campania region, southern Italy, where jointly with a phenomenon of a declining trend in residential water use as a share of GDP, we also observe a structural change in the quality of a groundwater body, the A.I.R. well field, which is used as a buffer stock for meeting excessive water demand. The overexploitation of agricultural lands in the investigated study area has certainly contributed to this phenomenon. Our evidence highlights two issues of groundwater management that can coexist with a virtuous process of water decoupling: the trade-off between quality/quantity degradation and the difficult role of water utilities that must deal with compelling and contrasting pressures, i.e., social vs. environmental pressures.