天然水源 meaning in Chinese

natural water source
open water supply

The unclean nature of the drinking water was the main cause for the spread of the plague
天然水源不洁，是疫症蔓延的主要原因之一。
Answer : conditional bourg should introduce municipal fire control to manage a network , rural fire control still can use the natural source of water such as well , pond , river with water
答：有条件的村镇应引入市政消防管网，农村消防用水还可以利用水井、池塘、河流等天然水源。