Answer:
use bigger dams,
the underground system clear
make sponge city
Explanation:
At the center its weight is zero. Or you can argue by symmetry: if the weight is not zero, in what direction would it act?
The variable you would need to keep track of is hight
Formation of groundwater i think
1) sun
2)high in the sky
3)bigger
Explanation: I hope this is correct but if not sorry
