"We need to be able to cope with that growth which will support a prosperous district.
"At the moment, for example, Waipukurau's drinking water comes from a reservoir on Pukeora hill. If something happens we could run out of water in half a day so one of the things we need to look at is a second reservoir."
As well as expansion in the drinking water network across the townships, water treatment would also be required, at a projected cost of about $12 million over the next 10 years.
Wastewater treatment upgrades and extensions were also proposed, at a cost of $7.5m over the next 10 years, and stormwater improvements were expected to cost close to $1m over that time.
Ms Walker said the proposed investments would go out to consultation early next year, but the expos held on Thursday and Friday this week gave the public the opportunity to find out more about what was planned, and give feedback about the areas they felt were the most important.
Large numbers of people had taken the opportunity to visit the expos where interactive displays were set up showing how the wastewater and stormwater systems worked.
One display allowed people to run water through a tap and watch a water meter ticking over, another showed the journey water travelled from a flushed toilet and through the pipe network, and there were puzzles and games on a water theme for younger visitors.
"We have had a fantastic response - people are genuinely engaging and want to understand what's going on," Ms Walker said.
"We have not made any decisions on any investment yet - we are presenting a plan and we want to find out whether people support it or not."
Although the planned expenditure would have an impact on rates, these were unlikely to increase by more than 3 per cent, and the burden would be reduced with the likelihood of more people coming to live in the district.
Feedback from the expos and other council pop-ups, including one at today's CHB A&P Show, closed on November 19.
It would be compiled over the next two months and then formal consultation on the Long Term Plan would begin in February/March next year.
More information on #thebigwaterstory and ways to give feedback were detailed on the council website.