I am a newbie for hydrology. If the question seems to have "well known answer", I appreciate if you point me to the resources. I will add details to the question based on comments.
Consider a town of 30km x 30km, nearby a hill, in a place where rain averages 40cm per year. The town is at an average elevation of 30m compared to the surroundings. It gets water mainly from rain. The water table seems to drop off as we walk away from the hill (30m near the hill, 90m once we walk 30km away from the hill).
If we concertize the town (fill every road, every open place with concrete 1m thick), what effect would that have on water table (water availability in earth)? Would the water flow away and sink into outer places (away from the town)?