This paper describes two common groundwater logics in Tamil Nadu: that of dowsing and that of modelling. Both rely on intimate knowledge and great dedication but have legitimacy and status in different communities. Groundwater experts celebrate and value modelling for assessing well and aquifer conditions, but at least when among peers – dismiss dowsing logics for being 'non-scientific'. Farmers and others interested in digging and drilling wells, on the other hand, routinely call in the help of dowsers, or water diviners, for determining well locations (and often depths). Rather than entering the science-dowsing controversy, this paper starts from the observation that modellers indubitably make use of the wisdom of dowsers: they use known well locations and depths to make their predictions more accurate and sensitive. This is why we think it is worthwhile to assess the practices of both in a more symmetrical way. For this we engage in a care-ful comparison of these two ways of knowing, showing that despite their differences, modelling and dowsing have many things in common. Both require years of education and training, and both modellers and dowsers take pride in being meticulous and insist on the need for repetition and fine-tuning to perfect their routines that is, to mathematically represent aquifers or magnetically sense groundwater flows. So, does dowsing or divining as a 'beyond scientific' form of knowing have something to offer when it comes to sustainable groundwater governance? The ways in which a water diviner practises care – seeks to improve farmer livelihoods, gets compensated, and senses the right place for a well (which is not about whether you could, but also whether you should dig at a certain location) – suggests that this may be so.