A detailed gradiometer survey was conducted over a linear scheme on land at Newark Growth Pipeline, Nottinghamshire, a water main along a 22 km route (Western extent:467829 343648; Eastern extent: 480316 346251). The site consists of a 60 m wide corridor across land between Gunthorpe and Balderton.The cart-based gradiometer system used a Carlson BRX7 GNSS receiver, which receives corrections from a network of reference stations operated by the Ordnance Survey. The detailed gradiometer survey was undertaken using four SenSys FGM650/3 magnetic gradiometers spaced at 1 m intervals and mounted on a hand-pushed non-magnetic cart. Data were collected with an effective sensitivity of ±8 μT over ±1000 nT range at a rate of 100 Hz, producing intervals of 0.02 m along transects spaced 4 m apart. Data from the survey were subjected to minimal correction processes. These comprise a ‘Destripe’ function (±5 nT thresholds), applied to correct for any variation between the sensors, and an interpolation used to grid the data and discard overlaps where transects have been collected too close together.