Skillingbro Spring and Thingbæk Spring

Several of the springs on the western side of Gravlevdalen once supplied water to fish farms that are now closed. The only springs in the area still used for fish farming are the springs at Skillingbro and Thingbæk.

Skillingbro Spring

Skillingbro Spring is located behind Skillingbro Naturskole. The spring is an artesian well – a man-made spring where groundwater under pressure is forced up through a pipe.

The word artesian refers to Artois in northern France, where pipes were driven into the ground as early as the 12th century to make pressurised groundwater rise to the surface. At Skillingbro, the pressure is caused by a water-retaining layer inside the hillside behind the spring. This layer consists of hardpan or clay and holds the water higher up in the hill than the pipe that pierces the layer further down. As a result, the water is under pressure and may rise out of the pipe.

The former Park Spring was also located in this area. It supplied clean water to the Urban brewery in Aalborg, where the water was used, among other things, to produce Park lemon soda. After the construction of Route 180, it is uncertain whether the former Park Spring and Skillingbro Spring are one and the same. However, it is certain that the groundwater flowing in the two springs is the same.

Today, Skillingbro Spring supplies water to an organic museum fish farm with limited production. The spring produces around 25 litres of water per second. The water that is not used in the fish farm continues through a restored stream towards Lindenborg Å.

Skillingbro Naturskole is used by Rebild Naturskole as well as for association meetings and courses.

Thingbæk Spring

Thingbæk Spring is located by Rebildcentret and is also an artesian spring. It produces around 35 litres of water per second. There is a fish farm by the spring, and in the past there was also a watermill here.