Ko te paparanga pumau o te wai (te paparanga kirikiri whakapumau te sima), e mohiotia ana ko te paparanga parewai, te paparanga parewai ranei, he waahanga nui o te mahi miihini rori. Kei waenganui i te paparanga whakakī o raro me te paparanga papa, ko te kaupapa matua ko te aukati i te heke whakarunga o te wai o te whenua me te makuku, ki te whakarite i te pumau o te whakakii o raro me te kaha o te kawe o te papa. Ko nga mea matua e whakamahia ana ko te uku, te onepu, te paru, te ciment, te para maitai me era atu mea. Ko enei rauemi ka taea te whakamahi takitahi, te whakakotahi ranei ki a raatau ano i runga i o raatau ahuatanga kia pai ai te aukati wai me te whakakotahitanga. Ko te nuinga o nga tikanga hanga he tikanga whakatiki pukapuka rapa, tikanga whariki me te tikanga rehu. Ko enei tikanga hanga kei a raatau ake ahuatanga, me whiriwhiri i runga i te ahuatanga motuhake o te kaupapa. Ko te paparanga pumau wai he hononga matua hei whakarite i te pumau me te mahi o te huarahi. Ahakoa he paparanga hanganga karekau e aro nuitia e te tangata, he mea tino nui tana mahi me tona awe.