# Why the groundwater depth is different in same area

I recently measured groundwater levels using a tape in three different boreholes for where the holes are in same area. Each hole had a different level of water. Holes A and B are just 4 meters apart and hole C is about 70 m from holes A and B.

The water depth in A was 12 ft (3.7 m), in B it was 9 ft (3 m) and in C it was about 71 ft (22 m). How can the water depth be different for holes so close to one another in the same area?

I asked professor about this and he replied, it is due to different heights of each borehole and asked me to Google it. I assumed that since water in equilibrium has the same water level, so the water in each borehole will be at same depth. But the readings doesn't match with my assumption ? What could be the reason?

• I would naively think localized changes in elevation wouldn't be matched with large changes in the absolute level of the water table, and so would mean the groundwater is at different depths relative to the surface. That the forces that set groundwater height aren't just in equilibrium vertically, but also horizontally. But not a topic I know much about. Commented Oct 15, 2023 at 23:12
• Is there another large well in the area that significantly lowers the water table at well C? Are wells A and B close to a river or stream? Commented Oct 15, 2023 at 23:50
• @JeopardyTempest sorry this works drive.google.com/… Commented Oct 16, 2023 at 2:13
• Presumably, you're asking about some specific data from the paper that you've linked to. Where exactly is this in the paper? Commented Oct 16, 2023 at 3:02
• Things to consider: are the holes on flat ground or a slope? Is the geology of the area uniform? Porosity & permeability affect ground water movement. Is hole C near a depletion source? Is there more than one water table, is there a perched water table in the area?
– Fred
Commented Oct 16, 2023 at 8:16