A new survey has shown that 52% of people admit they waste water, while a quarter believe they don't need to conserve it.
The survey was carried out by Behaviour & Attitudes on behalf of Irish Water.
1.7 billion litres of water is pumped to homes and businesses each day across the country by the utility company.
Irish Water is today launching a water-conservation campaign encouraging people to only use what they need, saying it's vital to safeguard the supply for future generations.
They're also looking to highlight the "economic and environmental cost" of providing safe clean drinking water.
Irish Water's Tom Cuddy said it is also important given the challenges of last summer's drought.
He explained: "Some of our supplies in some of the rural areas are challenged, because they didn't recover fully from the drought.
"Fortunately in the Dublin region there has been a very substantial recharge, and in most of the urban areas.
"Nevertheless, in overall terms our headroom is diminishing - there's growth and a lot of other demands on the resource. We really need to start locking it in in a sustainable way."
Mr Cuddy said there are a number of things people can do to reduce their water usage.
He observed: "We have the straightforward [measures] for the household.
"Turning off the tap... we calculate it saves about six litres a minute by not having the tap running when you're brushing your teeth.
"Obviously showering is much more conservative than having a bath - but even the duration of people's showers... certainly teenagers could perhaps shower for a few minutes less, and they'd still be sparkling."
Irish Water also says people used 30 fewer litres of water than usual during the drought last summer, suggesting the positive response to hosepipe bans has helped prompt the new conservation campaign.
