Prerequisites
- The harmfulness of rainwater is kept as low as possible given the state of the art.
- The discharge is compatible with the requirements regarding water characteristics and other legal requirements.
- Where necessary, plants or other facilities will be constructed and operated to meet these requirements.
Documents required
Which documents you need for your application varies depending on the type and scope of your project. In a preliminary discussion with the responsible water authority, you can clarify which documents are required in your case.
For surface waters:
- Application form
- Explanatory report
- Site plan (scale 1:5,000)
- Extract from the property map (scale 1:1,000)
- Extract from the property register
- Proof that infiltration is not possible on site
- Property drainage plan (according to DIN 1986-100: 2016-12, including discharge points)
- Detailed plan of discharge point
Optionally, the following additional documents may be required:
- Power of attorney for applicant (if not permit holder)
- Consent of other affected property owners
- Data sheet choke
- Detailed plan (with sections) throttle
- Information, representation and calculation of the required rain retention facility (including flood proof and KOSTRA rain data used)
- Assessment of the pollution of rainwater and the need for treatment (according to DWA-A 102-2)
- Analysis results
For the infiltration of rainwater:
- Application form
- Cadastral map extract
- Site plan or drawing of the planned construction project or the property with entry of the areas to be drained, the rainwater pipes and infiltration facilities (scale at least 1:500)
- Hydraulic calculation (calculation proof according to DWA-A 138 worksheet that the infiltration systems can absorb the expected amounts of rainwater)
- Information on the type and size (e.g. diameter, total depth, inlet height) of the infiltration facilities and cross-sectional drawing / schematic diagram
- Information on the subsoil conditions (e.g. list of soil layers with near-surface groundwater levels / subsoil assessment or subsoil information from the State Geological Office)
In justified individual cases (for example in the case of old systems in streets that have been subsequently converted), the above requirements may be deviated from after prior consultation with the responsible authority.
Please note
There is no need for a permit if no adverse changes to the groundwater are to be expected. You can find the requirements in the Rainwater Infiltration Ordinance. You then only have to notify the responsible authority of your project. Contact the authority if you are unsure whether you need to apply for a permit.
Deadlines
There is no legal deadline. Apply for permission well in advance of starting your project.
