A proposal to change the water supply bylaw for the Tararua District will affect some properties in Norsewood and Akitio which could mean residents will need to purchase new storage tanks.
It is proposed to implement a new requirement for residents in Akitio and Norsewood to increase existing or new storage tank capacity to 20,000 litres minimum, within a year of the adoption of the bylaw.
The Havelock North water enquiry has identified a number of risks which must be addressed across New Zealand, Peter Wimsett, council's manager of strategy and district development, said.
"Until recently, roof water was considered a way to supplement household water, however, this is untreated and can contaminate the treated water provided from the council supply," he said.
"It does not make sense to go to the expense of installing 21st-century water treatment systems only for people to remain exposed to almost certain contamination from roof water. The wind carries many contaminants on to roofs while other direct sources of contamination may include birds, insects and other animals. The free available chlorine in the treated water may not be sufficient to also treat the roof water when they blend together.