Irish Water has issued a hosepipe ban for west Cork in a bid to "safeguard supply for essential purposes".
The Water Conservation Order, which prohibits the use of garden hoses and other non-essential uses of water, will be in place for 30 supplies in the region from midnight tonight until midnight on 26 September.
The number of people impacted by the Water Conservation Order is 38,000, which equates with 14,000 households and businesses.
The order follows a long period of dry weather combined with a large increase in demand, as a result of which water supplies in west Cork have reduced to "historic lows", Irish Water said.
We need your consent to load this rte-player contentWe use rte-player to manage extra content that can set cookies on your device and collect data about your activity. Please review their details and accept them to load the content.Manage Preferences
It will take six to eight weeks of rainfall for the water to replenish, the State-run utility company added.
Met Éireann has forecast a further spell of dry, warm weather for the next two weeks, which will increase the pressure on already depleted water supplies.
Irish Water in partnership with Cork County Council is tankering water to three supplies and there is a potential need for tankering to additional supplies in west Cork in the next two weeks.
Margaret Attridge of Irish Water said: "Water levels at our surface water and ground water sources in the west Cork area have reduced to historic lows.
"As demand continues to outstrip supply in west Cork and with further dry weather predicted, we have taken the extra step of implementing a Water Conservation Order to safeguard local water supplies."
Speaking on RTE's Morning Ireland, Ms Attridge said that in west Cork in particular there has only been 7mm of rainwater compared to other places such as Sligo, which has had 30mm.
She said there was "unprecedented low levels of rainfall through November into January", the time of the year resources would fill up and there would be enough water to keep the country going through the summer.
Then July was extremely dry with rainfall 76% below average.
She said it is really important to save water now as the weather forecast is for the next few weeks for continued dry weather.
"It's really important that we really maintain the water that's left in our resources for essential services over the coming weeks and that's why we ask people now to conserve water."
The water supplies covered by the order are Adrigole, Allihies, Bantry, Bayview, Caheragh, Cahermore, Cape Clear, Castletownbere, Clonakilty, Cluain Court Allihies, Coppeen Crookhaven, Crosterra, Drinagh, Dromore Bantry, Dunmanway, Durrus, Dursey Island, Glengarriff, Goleen, Johnstown, Kealkill, Kilcrohane, Lyre Clonakilty, Reenmeen West, Skibbereen, Tarelton, Toormore and Whiddy Island.