The financing assistance aims to modernize the country's water and sewage services, and cover the metropolitan area of the capital that receives water from the Torogoz treatment plant.
The plant supplies water to some 40% of the people living in San Salvador's metro area, the lender said.
The loan is also set to create an immediate response plan for a natural or human-caused emergency.
"We consider this vitally important to work for Salvadoran families exposed to droughts, storms and floods who suffer continuously from the interruption of their water services," said Carine Clert, the World Bank's manager for El Salvador and Costa Rica.
Clert stressed that improving water infrastructure will particularly benefit women in the country, who are disproportionately caregivers and heads of households.
The announcement comes shortly after the World Bank announced
another loan
to Panama, intended to support the country's sustainable
growth and climate resilience.
(Reporting by Nelson Renteria; Editing by David Alire Garcia)