Baotu Spring

Baotu, also called Lan Spring, is the source of the ancient Luo water and heads Jinan's list of seventy-two famous springs. Three outlets push water up in a tight line, and the noise of it is the reason the Qianlong Emperor gave it the name Number One Spring under the Heaven. It is fed by an Ordovician karst aquifer whose recharge area lies in the mountains south of the city; the springs it feeds draw about 300,000 to 350,000 cubic metres a day, and Baotu's own water holds a constant 18 degrees Celsius. It is a typical artesian well: below the city an impermeable granite bed lies under limestone, and water rises through the rock fissures under pressure.