ʻO ka mīkini pahu pōhaku ʻekolu lima piha i hana ʻia e kā mākou hui he mau mea maikaʻi o ka hōʻemi ʻana i ka ikaika o ka hana o nā limahana, hoʻomaikaʻi i ka ʻoihana hana, hoʻomaikaʻi i ka hana ʻana, a hōʻemi i ka hilinaʻi akamai o nā mea hana. He holomua ia ma ke kahua o ka hana ʻenehana tunnel. He kūpono ia no ka ʻeli ʻana a me ke kūkulu ʻana i nā tunnels a me nā tunnels ma nā alanui, nā alahao, ka mālama wai a me nā kahua kūkulu hydropower. Hiki iā ia ke hoʻopau maʻalahi i ka hoʻonohonoho ʻana, ka wili ʻana, ka pane ʻana, a me nā hana hoʻoponopono o nā lua puhi, nā lua bolt, a me nā lua grouting. Hiki ke hoʻohana ʻia no ka hoʻouka ʻana a me ka hoʻokomo ʻana i nā hana kiʻekiʻe e like me ka bolting, grouting, a me ka hoʻokomo ʻana i nā auwai ea.