Groundwater

In order to protect the groundwater both in terms of quantity and quality, its use requires a permit from the lower water authority or notification.

The following measures require a permit or notification:

• Drilling, e.g. for subsoil exploration, construction of measuring points or development as wells
• Extraction of groundwater, e.g. for garden irrigation, for water-to-water heat pumps or for production processes (notification is sufficient for garden wells for non-commercial use).
• Construction dewatering
• Construction of a system for geothermal heat utilization
• Infiltration of precipitation water that is not contaminated with harmful substances over a large area or in troughs or by means of a shaft, pipe or infiltration trench
• Infiltration of wastewater
• Safekeeping of wells

Prohibitions and restrictions in drinking water protection zones must be observed. An exception to the prohibitions may be possible on application.

Detailed information on the notification and application procedure can be found on the city's service portal:

• Groundwater extraction, drilling and geothermal energy
• Domestic wastewater - discharge and infiltration

For further information, please contact the lower water authority.

Jena's drinking water supply is provided by the JenaWasser special-purpose association.

Most of the water comes from the deep wells in the Saale-Roda valley in the south-east of Jena. In addition, the districts of Jena-West and Jena-South as well as the rural districts of Münchenroda, Remderoda, Isserstedt, Cospeda, Lützeroda, Closewitz, Krippendorf and Vierzehnheiligen are supplied with long-distance water from the Ohratal dam.

The surface water from the dam is treated at the Luisenthal waterworks and then supplied to Jena.

The groundwater from the deep wells first reaches one of the waterworks in Burgau or Drackendorf, where it is treated for the drinking water supply.

Further interesting information about drinking water in Jena can be obtained directly from the JenaWasser special purpose association.

Catchment areas of drinking water extraction plants must be particularly protected against adverse changes. Water protection areas are designated for this purpose. These are subdivided into three protection zones:

• Zone I: Catchment area of the well or spring
• Zone II: Narrower protection zone
• Zone III: Extended protection zone

The protection zones were defined on the basis of the geology and hydrogeology of the respective catchment area. Different restrictions on use apply to each zone.

Jena is part of all three protection zones. For example, extensive areas south of the BAB 4 highway are located in protection zone III of the Saale-Roda Valley wells.

In this area, the designation of new building areas, the construction and expansion of cemeteries, the extraction of raw materials or the handling of water-polluting substances, among other things, can lead to impairment of the groundwater.

In contrast, protection zones I and II for the Fürstenbrunnen well and the Maua deep well cover a comparatively small area. Even more extensive protection regulations apply here.

An overview of the water protection areas in Jena can be found on the Geoportal of the Free State of Thuringia.

Near-surface geothermal energy utilizes the available temperatures down to a depth of approx. 400 m.

In Jena, both brine-to-water heat pumps in the form of geothermal probes and ground collectors and water-to-water heat pumps are used.

A mixture of water and antifreeze is used as the heat transfer medium for brine-to-water heat pumps, while groundwater is the heat transfer medium for water-to-water heat pumps.

A water permit from the lower water authority is required for geothermal probes; collectors are subject to notification.

The installation of a water-to-water heat pump also requires a permit under water law.

Further information can be obtained from the lower water authority and on the city's service portal: Groundwater extraction, drilling and geothermal energy.

Boreholes that are to be drilled deeper than 100 m require additional notification under mining law from the Thuringian State Office for the Environment, Mining and Nature Conservation (TLUBN).