Matsyapurana 154.511

154.511

evaṃ nirudake deśe yaḥ kūpaṃ kārayedbudhaḥ
bindau bindau ca toyasya vasetsaṃvatsaraṃ divi //

Pārvatī said—"One who makes a well in a place where there is scarcity of water, lives in heaven for as many years as there are drops of water in it One large reservoir of water is worth ten wells One son is like ten tanks, and one tree is worth ten sons This is My moral and I am prepared to protect the universe to the same end"—511 512