https://en.wikipedia.org/wiki/Water_table
(The first time I heard this was a big "aha" / "of course it works that way, how else would it work" moment for me. Ala XKCD 10000 [0]. Hopefully you're one of today's lucky winners!)
A drainage basin or 'catchment area' is any area of land where precipitation collects and drains off into a common outlet, such as into a river, bay, or other body of water. The drainage basin includes all the surface water from rain runoff, snowmelt, and nearby streams that run downslope towards the shared outlet, as well as the groundwater underneath the earth's surface.[1] Drainage basins connect into other drainage basins at lower elevations in a hierarchical pattern, with smaller sub-drainage basins, which in turn drain into another common outlet.[1]
> The proposed EU ban would still allow neonicotinoids to be used in greenhouses and as a flea treatment for pets. A new Greenpeace study suggests neonicotinoids are frequently found in waterways close to greenhouses where they have been used.