DAR ES SALAAM, March 20 (Xinhua) -- The World Bank said on Tuesday Tanzania lagged behind in expanding and sustaining basic water supply, sanitation, and hygiene (WASH) coverage.

"More than 23 million citizens retrieve drinking water from unimproved sources, and 41 million people use unimproved sanitation facilities," said the World Bank in a report launched in the commercial capital Dar es Salaam. Tanzania's population is 54 million.

"Adequate WASH is a crucial component of basic human necessities that allow a person to thrive in life," said Bella Bird, World Bank Country Director for Tanzania, Malawi, Somalia and Burundi.

She added: "Outbreaks of cholera and other waterborne illnesses do not only overburden health systems and increase premature deaths, they do also leave a negative mark on the individual's social mobility, health, quality of life, and their human capital."

Tanzania will need to invest more in WASH if it is to achieve the Sustainable Development Goals (SDGs), improve human development outcomes, and accelerate poverty reduction, according to a new WASH Poverty Diagnostic published by the World Bank.

The Tanzania WASH Poverty Diagnostic is part of a multi-partner Global WASH Poverty Diagnostic initiative being implemented in 18 countries across regions.

Its objectives are to highlight the priority gaps in WASH access; identify regions and population groups that are most deprived of higher-quality WASH services; demonstrate how investment in WASH can aid poverty reduction and human development strategies; and identify the major institutional constraints that hold back effective WASH service delivery.

While Tanzania has achieved significant growth, averaging 6.5 percent over the past decade, with a modest reduction in poverty from 34 percent to 28 percent (2007-2012), it lags in expanding and sustaining basic WASH coverage, said the report.

"As Tanzania seeks to achieve the ambitious SDG targets, it is more important than ever to assess the current state of WASH service delivery to inform evidence-based strategies that target gaps in service delivery," said George Joseph, World Bank Senior Economist, who co-authored the report.

"The country needs to see the new SDG era as a good opportunity to move its WASH agenda forward ambitiously to improve human development and eradicate poverty," said Joseph.