Latest: The public has been warned that drought conditions will get worse before they get better with a "continued depletion" of water stocks, writes Elaine Loughlin.
Minister for Housing, Planning and Local Government Eoghan Murphy has said that people will be disrupted by hose bans and other conservation efforts for the foreseeable future with no rain in sight.
Local authority executives attending the Housing Summit in Dublin today were also briefed on water conservation plans during the drought conditions that are expected to last for at least a number of weeks.
Mr Murphy said: "I know for a lot of people it can be a good time of the year and to have a summer where there is actually sun to go to the beach or to spend time with friends, but a lot of people are experiencing difficulties because conservation efforts are already underway.
"The vast majority of people aren't using water in stupid ways, the vast majority of people aren't being selfish with their water usage, but I think it's important that we are going to have to recognise that conservation efforts are going to have to continue for quite some time, this is going to get worse before it gets better.
"We are looking at a continued dry spell and during that time we are going to see two things, we are going to see a continued depletion of our raw water stocks and we are going to see a heightened risk of fires and more serious fires," he said.
Figures from Irish Water show demand in the Greater Dublin area has gone down from 615 megalitres on June 27 to 578 megalitres yesterday.
Currently, there are restrictions at 43 supplies around the country.
Restrictions are also now possible at two Cork water plants serving Clonakilty and Bantry.
Update - 9.22am: Irish Water expects hosepipe ban to continue into September
Irish Water is warning that supplies could be restricted until the autumn.
The hosepipe ban will be extended this week to Laois, Kilkenny, Limerick, Kerry, Galway and Waterford.
It started in the greater Dublin area yesterday to try and counteract falling reservoir levels during the heatwave.
Managing Director of Irish Water, Jerry Grant, does not expect things to improve any time soon.
He said: "My expectation now is that this likely to go on right into September because the kind of drought we are seeing at the moment shows a serious deficit in groundwater levels.
"That means obviously that, unless we get torrential rainfalls in August, which we sometimes do, we will see a very slow recovery, especially in groundwater sources where recharge takes a lot of time."
9.22am: 'Govt and Irish Water using water shortage to push water charges agenda,' says TD
A leading figure in the water charge protests says the Government is using the current shortages to try and re-introduce the fees.
Independent TD Joan Collins has introduced legislation to the Dáil that proposes the public get a vote on putting public ownership of water in the Constitution.
She believes domestic users are being scape-goated when industry and agriculture are the biggest water users.
She claims Irish Water and the Government are guilty of pushing an agenda whenever the public water system runs into problems:
Ms Collins said: "They used when we had the snow and there were problems there when we had the water outage.
"So every time something happens, the State and Irish Water would say we have to pay for our water, put meters in.
"People will not accept that, they resisted it, rejected it and we will continue to do so."
Meanwhile, Irish Water is expected to extend the hosepipe ban to parts of Limerick, Kilkenny and Laois this week.
The measure, which bans the non-essential use of water, has been in place in the Greater Dublin Area since yesterday morning as supplies remain under pressure from the heatwave.
According to the Irish Independent, Irish Water is also due to decide tomorrow if they will take a tough stance on enforcing the water conservation order.
Anyone who breaks the hosepipe ban could face prosecution or a €125 fine.