Irish Water has warned that flooding and power outages may compromise the operation of water treatment plants and as a result the safety of drinking water.
It says incidents plans are in place and crews are on standby to deal with the effects of Storm Ophelia.
Irish Water say that conditions are likely to result in power outages at critical water and wastewater installations which could compromise service delivery and heavy rainfall may also increase the risk of flooding.
Where risk arises, the company says it will work with the HSE to impose precautionary boil water notices as necessary.
It says it is collating information and will be updating its website constantly, but crews may not be able to respond to breakdowns in plants until it is safe to do so and this may lead to loss of service for a period.