HOWAS 21 is managed and hosted by the GFZ German Research Centre for Geosciences. There are three user groups that are provided different levels of access permissions to use HOWAS 21:

• "World": Users from the open public with an interest in the topic are provided some basic high level information about flood damages.
• User group I (Data providers): Institutions that have provided data meeting all quantitative and qualitative criteria to be imported into HOWAS 21. Members of this group have full access to all data in HOWAS 21.
• User group II (Users with no ownership of relevant data): Users who perform scientific research or other non-commercial project work with the data (projects in the scope of official flood risk management, e.g. the development of flood mitigation concepts, are considered to be non-commercial, if not scientific), but who do not own any data that could potentially be of benefit for HOWAS 21. Users in this group can be offered restricted access to the data repository. In return research results are to be communicated to the HOWAS 21 team.

All potential users in either group I or II need to register and sign a data usage agreement.
Contract templates are provided for download:

• Data usage agreement user group I
• Data usage agreement user group II

Flood damage data in HOWAS 21 are anonymised. A combination of flood damage data records with different other datasets that require exact geographical location information had only been done -where possible and necessary- before the data was aggregated for import into HOWAS 21. Any location attributes present in the HOWAS 21 data are generalised to a point at which the identification of single objects is no longer possible (e.g. aggregation to postal code areas or communities). HOWAS 21 takes data protection seriously and respects the interests of the data providers and users alike.