Karlovy Vary, together with 10 other spa towns, is a transnational UNESCO World Heritage Site "Famous Spa Towns of Europe". In the spring zone of the Karlovy Vary spring structure, over eighty active thermal mineral water intake objects have been documented, of which 19 are certified as natural healing sources in the sense of the Spa Act. The spring zone is approximately 150 m wide and 1,700 m long.The hottest spring is the Vřídlo with a maximum temperature of 73.4 °C, and of the small springs, the Prince Wenceslas Spring with a temperature of up to 66.7 °C. On the contrary, the coldest are the Sadovy Spring with a temperature not exceeding 40 °C and the Hadí Spring with an average temperature of 28 °C, in which, however, the springing thermal water is already diluted by the river water. The thermal spring Štěpánka cools down during its ascent through a 150 m deep borehole to the surface from the original 60 °C at the bottom of the borehole to 9 – 13 °C at the overflow.
Karlovy Vary
For the needs of Karlovy Vary’s comprehensive spa care, thermal water has been collected since the 1980s mainly from boreholes from depths of over 50 m. Inclined boreholes replaced the original shallow collection of the Vřídlo, whose depth did not exceed approximately 10 m. Smaller springs are captured by vertical boreholes from depths of 4 to 37 m. The collection boreholes are equipped with frames made of special anti-corrosion steel. Mineral incrustations from hot thermal waters (vřídlovec) pose a particular problem when pumping water. They can clog pipes in a short time.
Photo 1: Johann Wolfgang Goethe visited Karlovy Vary four times and spent almost three years of his life here
Photo 2: Hot spring. The thermal mineral water is collected by the BJ-70 borehole
Photo 3: Mill Colonnade