The company delivers water and wastewater services to more than three million people across Wales, Herefordshire and Deeside.
The EIB loan will help Dwr Cymru keep its costs down and meet the £1.5bn capital investment program in the five years from April 2015.
Projects include £120m investment program to upgrade or reconstruct 12 water treatment plants, and the £15m RainScape investment in Llanelli and Gowerton.
The RainScape scheme includes refurbishing sustainable urban drainage systems to capture, divert or slow down the rate at which rainwater enters the company’s sewer network, EIB said.
EIB has provided Dwr Cymru Welsh Water with £500m since 2001 helping finance more than £1bn of capital expenditure in enhancing water and wastewater services across its operating area.
EIB vice president Jonathan Taylor said: "Continued investment in UK water infrastructure is essential to allow customers to access clean drinking water and sanitation that is amongst the best in the world.
"The new European Investment Bank engagement with Welsh Water announced today is the largest it has agreed with the company in more than two decades of doing successful business together. The impressive project seen in Llanelli demonstrates a clear commitment to protecting rivers across the Welsh Water area from pollution."
Dwr Cymru operates and maintains 27,500km of water mains, over 30,000km of sewers, 838 sewage treatment works and 66 impounding reservoirs.
Image: The RainScape scheme includes refurbishing sustainable urban drainage systems to capture, divert or slow down the rate at which rainwater enters Dwr Cymru’s sewer network. Photo: Courtesy of European Investment Bank.
