ʻO ke ʻano hou o ka wai wai he hana kiʻekiʻe o ka anti-permeability, ka wai-proofness, thermo-stability a me ka waiwai cryogenic, ikaika kiʻekiʻe a me ka elongation a loaʻa ke ʻano o ka pale ʻana i ka wā kahiko, ua hoʻohana nui ʻia no ka wai ʻole i ke kūkulu ʻana i ka hale o ka ʻoihana a me ke kūkulu kīwila, lalo, tunnel, lake artificial, etc.