The previous article is to help you find the depth of your water tables

I thought it might be helpful if you want to build underground (or even just put in a basement under a house you are building, to know the water tables in your area of the U.S. The U.S.G.S. likely can help you find the average water tables in your area. However, they mention that water tables are often seasonal most places in the U.S. too as they rise and fall during different times of the year.

So, for example, you might build something underground that might be great in one season but in another season you might have water coming through your walls (unless you prepare for water by using cement and swimming pool paint or something like that to protect yourselves from inundation underwater.

Also, building underground in any Flood plain isn't going to work long term either. So, one needs to be very practical about all this.

For example, even in the deserts where there are a lot of Dry washes if you are at a similar altitude of the dry washes even then, you could be vulnerable during a flash flood in an underground dwelling if you haven't prepared for all this before hand.