Water

As a rule, the use of a water body requires a permit from the water authority.

The following are considered to be uses of water bodies within the meaning of Section 9 of the German Water Resources Act (WHG):

• the abstraction and discharge of water from surface waters
• the damming and lowering of surface waters
• the introduction and discharge of substances (e.g. collected precipitation water or treated wastewater) into surface waters or into groundwater (see also rainwater -percolation-)
• the extraction and discharge of groundwater (for example, for groundwater lowering or field irrigation)
• Measures that are likely to cause permanent or significant adverse changes in the water quality of surface waters or groundwater (e.g. the construction and operation of geothermal probe systems).

Permission-free water uses (public use) are regulated in Section 32 of the Lower Saxony Water Act (NWG). These are, for example, bathing, diving, watering, scooping with hand vessels, ice sports, driving with vehicles without self-propulsion, as long as the rights of others are not opposed and the rights or the owner or riparian use of others are not impaired.

Groundwater abstractions

Groundwater withdrawals can occur through:

• Groundwater drawdown
• Field irrigation
• wells (garden irrigation / fire-fighting wells)

The use of environmentally friendly geothermal energy for heating purposes is of increasing importance.

Rainwater is the part of the natural water cycle and normally seeps into the subsoil on the spot. It contributes significantly to the recharge of groundwater . As the water percolates, it passes through various layers of soil, through which it is purified. It then collects in the groundwater-saturated soil zone.

Floodplains (ÜSG) are of great importance from the point of view of flood protection in two respects. On the one hand, they allow flood events to flow off without damage; on the other hand, the retention of water in the floodplains can reduce the flood peaks along the watercourse and thus reduce the flood risk for downstream riparians.

Indirect discharges are wastewater discharges from commercial and industrial operations and from public facilities into the public sewer system. If the wastewater contains hazardous substances, or if it originates from a branch of industry that is likely to contain hazardous substances in the wastewater, the indirect discharge requires a permit in accordance with Section 58 of the Water Resources Act (WHG) in conjunction with Section 98 of the Lower Saxony Water Act (NWG).

On properties that cannot be connected to the public wastewater sewer system, domestic wastewater must be treated using small wastewater treatment plants. Small wastewater treatment plants must comply with the generally applicable rules of technology. As a rule, new buildings and retrofits must have a general building authority approval or a manufacturer's declaration of performance. This also regulates the self-monitoring and maintenance of the system. Only in these cases are the properties exempt from the wastewater tax.

The notification form must be used for retrofits or new buildings. The notification must be submitted to the lower water authority for approval.

Installations in, on, over and under surface waters

Installations in, on, over and under surface waters must be constructed, maintained and operated in such a way that no harmful changes to the water are to be expected and water maintenance is not unnecessarily impeded.

These facilities include structural installations, such as

• Buildings
• bridges and footbridges
• underpasses, pipes and culverts
• moorings
• embankments and excavations

A permit from the Lower Water Authority is required for the construction and substantial modification of such facilities.

Required documents:

• Informal application for the construction of a facility
• Explanatory report
• General plan
• Section of cadastral map
• Longitudinal and cross sections
• Detailed drawings
• Possibly hydraulic calculation

The construction of ponds/stillwaters is a form of watercourse development and thus requires a permit if they are fed by groundwater (without sealing) or surface water.

Depending on their scope and size, they may require building permits.

A planning approval procedure is required for the construction of a watercourse. Instead of the planning approval procedure, a planning approval procedure can also be carried out if, in accordance with the

• Law on the Environmental Impact Assessment and the
• Lower Saxony Law on the Environmental Impact Assessment

there is no obligation to carry out an environmental impact assessment.

Required documents:

• Informal application for the construction of a watercourse
• Explanatory report
• General plan
• Section of cadastral map
• Longitudinal and cross sections
• Detailed drawings
• Possibly hydraulic calculation

According to the Water Resources Act (WHG), a watercourse development is the creation, removal and substantial transformation of a watercourse or its banks.

A substantial transformation occurs when the water body is permanently and significantly changed, for example by:

• Changes to the course (straightening, relocation, lengthening of the course).
• deepening
• Piping
• demolition of transverse structures

A planning approval procedure is required for the alteration of a watercourse. Instead of the plan approval procedure, a plan approval procedure can also be carried out if, according to the

• Law on the Environmental Impact Assessment and the
• Lower Saxony Law on the Environmental Impact Assessment

there is no obligation to carry out an environmental impact assessment.

Required documents:

• Informal application for the development of a watercourse
• Explanatory report
• General plan
• Section of cadastral map
• Longitudinal and cross sections
• Detailed drawings
• Hydraulic calculation

Current planning approval procedure:

• Renaturation of the Aller between Badelandbrücke and Vorsfelde

The maintenance of a surface water body includes its care and development as an obligation under public law. It must be oriented to the management objectives.

Substances hazardous to water are solid, liquid and gaseous substances that are capable of permanently and adversely changing the physical, chemical or biological properties of the water.

The objective of the European Water Framework Directive (EC-WFD) for surface waters is to ensure (prohibition of deterioration) or develop a good ecological and chemical status.

The legal bases for the work of the lower water authority are

• the Water Resources Act
• the Lower Saxony Water Act

and other legal regulations.