Dublin's water supply is too dependent on the River Liffey according to Uisce Éireann.
The utility says a new supply from the River Shannon is needed urgently.
The CEO of Uisce Éireann will tell an Oireachtas Committee this afternoon that the River Liffey is extremely sensitive to drought and contamination.
It's the main water supply source for 1.7 million people in the Greater Dublin Area.
The organisation has warned that the Eastern and Midlands region will have a 34% water supply deficit by the year 2044 unless the current system is upgraded.
It says the Water Supply Project - that will see water piped from the River Shannon to a reservoir at Peamount in Dublin - must proceed urgently.
