Grüner Pütz Roman Springhead

The facility is known as the "Green Pütz". This is the field designation of a valley meadow in the Urft valley in the district of Nettersheim. There you will find one of the source tappings of the Roman Eifel water pipeline, with which ancient Cologne was supplied with fresh (highly calcareous) drinking water from the Eifel. The source and channel are partially working again today. However, the water does not flow to Cologne, but into the Urft.

The Green Pütz is one of the spring taps of the Roman Eifel aqueduct that supplied the Colonia Claudia Ara Agrippinensium, ancient Cologne, with drinking water. The Mechernich mountain official C. A. Eick proved in the middle of the 19th century archaeologically that the Green Pütz was the outermost point of the Eifel aqueduct. The source catchment and the adjoining canal up to the railway embankment are now in operation again. However, the water flows behind the embankment, i.e. H. still in the valley, in the Urft. Source: Wikipedia

The oldest known example of water production in the Eifel is the Roman water pipe from Nettersheim to Cologne.
This 95.4 km long water pipe was one of the longest long water pipes in the Roman Empire.
It was a top achievement in Roman engineering and supplied Roman Cologne with good quality water from the Eifel from the 1st to the 3rd centuries.
Their daily output was up to 20,000 cubic meters. The water emerges from Middle Devonian dolomite and is collected in the so-called Roman spring in the Urft valley north of Nettersheim.

The water pipe to Cologne, also called the "Roman Canal", is mainly made of natural stone (sandstone, limestone, dolomite) and has a cross-section of 80 x 50 cm, the upper part almost always being vaulted. This Roman water pipe was in operation for around 190 years. Then one of the largest institutions of urban infrastructure north of the Alps had had its day.

During the major Franconian attack on the Roman Rhineland in the 2nd half of the 3rd century, the Eifel water pipe was also destroyed. In late antiquity, this grandiose supply facility was not put back into operation by the Romans and was therefore left to decay.

from: "Geological forays" by Wolfgang Spielmann, published by Rhein-Mosel-Verlag