Pro.La-Fellbach

0.6% of Germany's land area is used for agriculture and a further 14.5% for settlement and transport. Within the settlement and traffic areas, commercial areas take up a share of 18.6%. Commercial areas (GHD) thus represent a significant proportion of the land used, in addition to built-up areas for housing and industry. In order to protect the population from noise and pollutant emissions, commercial areas are often located on the outskirts of the city, where they meet equally productive agricultural land. This is also the case in the project area of the IBA'27 project "AGRICULTURE meets MANUFACTURING" in Fellbach.

So far, there have been no synergies between these two productive subspaces. If one takes a closer look at the respective material and resource flows of both, quite different theoretical potentials of synergy formation can be identified. If commercial structures generate large amounts of wastewater, CO2, rainwater and waste heat, agriculture requires water, nutrients, CO2 and heat to grow agricultural products. Both uses of these productive spaces are also united by a strong pressure to adapt to the effects of climate change. Both the commercial area in Fellbach, which is 67% sealed, and large uniform cultivated areas of the adjacent agriculture have a low storage capacity of rainwater. Heavy rains pose major challenges to both uses in terms of localized flooding (in the commercial area) or soil erosion (in the agricultural area). Also, these two productive areas have had little climatic activity. The Fellbach commercial area thus makes no significant contribution to groundwater recharge, or to evaporation. On the contrary, the largest urban heat hotspots are located here due to the high degree of sealing. Agricultural land can also have increased runoff, depending on soil conditions. In addition, fertilizer inputs can pollute groundwater and surface water. Increasing climate change will perspectively increase water demand in agriculture (which is already the largest water consumer globally).

The Pro.La-Fellbach project of the Stuttgart University of Applied Sciences and the East Bavarian Technical University Amberg-Weiden focuses on the identification of resources and synergies of sustainable water cycles between local industry and agriculture.

• How can productive landscapes (commercial and agricultural areas) be developed in a climate-sensitive manner?
• What synergies can be formed between the two forms of use?
• What rainwater and wastewater potentials can be tapped from commercial areas for agriculture?

In order to develop concepts for sustainable water use, the following steps are implemented: Determination of the current and future rainwater balance; quantification and qualification of wastewater generation.

For this purpose, corresponding potential studies are carried out, each with its own methodological procedures. The rainwater volumes are determined according to DWA measurements as well as on the basis of GIS analyses. The wastewater quantities are recorded via queries on quantities and quantities of the wastewater companies. At the same time, further approximations are made via typing approaches as well as queries of specific values about the locally located businesses.

The data obtained are assembled into a virtual water flow model. This forms the basis for the design of alternative water use concepts.

The study is to provide answers as to how the water balance of commercial and agricultural uses can be designed sustainably and efficiently. With comparative concept studies, new water cycles, treatment methods and synergies are to be demonstrated using the Fellbach iba project as an example and serve as a preliminary study for implementation planning.