Four are listed in Genesis (see ch.26 concerning Isaac and Abraham), but there may have been more.
catch rainfall, rivers and dig wells
Abraham lived there for 26 years and dug wells.
"Water table" means the level of water underground. So when you dig a well, you have to dig down at least to that level.
We dress appropriately, eat local foods, clear land for farms and dig wells.
We dress appropriately, eat local foods, clear land for farms and dig wells.
there are 20
That information is not given. Archaeologists have found ancient wells at Be'er Sheva which vary in depth from 40 feet to 100 feet.
First they dig the 2 wells of about 2-3 meters away from each other, then from each well they start digging a connector until the 2 ends meet.
you have to dig 100 feet
It's so that the people living in those dry places have access to water.
Which Abraham and which war? There have been many Abraham's and many wars.
The Dig - novel - has 231 pages.