Preserving biodiversity is one of the greatest challenges of our time. A vibrant district will emerge in Donaustadt in the coming years. 11,000 people will live at Heidjöchl in the future. Diversity is an important guiding principle in the planning process. This also applies to fauna and flora. Through citizen science, urban planning is ensuring that biodiversity in the new district remains as high as in the current areas. With the support of experts and an app, the citizen science project aims to involve the public in species surveys (expeditions) and use the collected data for open space and green space planning in the new district.