Thousands of families in Vietnam's largest city will get their own water supply for the first time under a programme funded by a $1 billion loan from the Asian Development Bank (ADB), the bank said Tuesday.

Almost 20,000 families in Ho Chi Minh City will get piped water by the end of 2015 under the scheme, which will also improve water pressure and coverage for hundreds of thousands of others, the ADB said.

"Poor water coverage hits poor families the hardest, and this investment programme will benefit these families most," Ayumi Konishi, ADB's Vietnam country director, said in a statement.

The ADB, which aims to reduce regional poverty, is providing $138 million for the Ho Chi Minh City project under its $1 billion low-interest loan scheme to improve Vietnam's water system until 2020.

Vietnam's government wants a total investment of almost $2.8 billion in the water sector by that time, when it hopes to attain 90 percent piped-water coverage, ADB said.

Vietnam has developed rapidly since it opened to the outside world 25 years ago. The government says the proportion of poor households in the country of 86 million has fallen to 9.5 percent.

The country's communist rulers hope to build Vietnam up to become a modern, industrialised nation in a decade.