Havelock North water-supply bores may be put back into use, says Hastings Mayor Lawrence Yule.
They were shut down after several thousand people were sickened by campylobacter in August but may be re-opened for the summer months.
He said as summer approached and people started watering gardens and lawns, more might be needed.
The council's Hastings bores had enough water for Havelock North and urban Hastings, the problem was supplying it to Havelock North.
"The challenge is in the physical infrastructure, to get the water into Havelock North," he said.
"We are currently looking at how we might do that - whether we need to put another pipe down Havelock Rd, for example."
Another option was returning to the Havelock North aquifer and giving the water UV treatment to kill bacteria "so if we do run short we can start the Havelock North bores this summer".
When the Brookvale Rd bores were shut down Havelock North was instead supplied with Hastings water.
Until then Havelock North and Hastings had separate water supplies but were connected by a previously unused pipe.
The Havelock North aquifer was rated a confined aquifer, meaning it was protected by impermeable layers of soil that prevented groundwater seeping into it.
Some theorised water from the Tukituki River could have been the source of bacteria but the Hawke's Bay Regional Council said extensive sampling showed no evidence of groundwater contamination.
The testing also showed no evidence of campylobacter in the river.
Mr Yule said he believed the campylobacter, from either sheep or cattle, was from a local source "very close to where the bores are".
The current Brookvale Rd permits were issued prior to the Resource Management Act and do not include a condition for wellhead integrity.
After campylobacter got into the water in 1998 a report said water draining from a sheep paddock was able to enter the bore.
Wellheads were then upgraded.
Havelock North water was temporarily chlorinated in 1988 as it is now. The chlorination is due to remain until the end of November, a three-month requirement of the New Zealand Drinking Water Standards after a bacterial incursion.
The Government has commissioned an inquiry into the recent outbreak, which will report back by the end of March.
It will focus on how the water supply became contaminated, how it was addressed, how local and central government agencies responded and how to reduce the risk of future outbreaks.