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 gives 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.

Concepts and strategies for sustainable water cycles between industry and agriculture: Various alternative water utilisation concepts were developed and evaluated, including strategies for rainwater utilisation in industrial estates and transfer to neighbouring agricultural areas. A particular focus here was on identifying the necessary storage systems and their contributions to meeting the temporally and climatically variable demand in agriculture. The use of grey water and wastewater as a resource during dry periods was also examined. In addition, the costs of rainwater drainage and drinking water supply in the different climate adaptation scenarios were determined.

Urban Water Potentials, interactive, digital and participatory tool (https://urban-water-potentials.de/): To raise awareness among local tradespeople and the wider public, an easy-to-use web-based tool was developed that provides information on the area and the various properties and also allows users to playfully test the effects of justification measures on the respective water balance and resulting costs using a scenario manager.

Transferability concept: Finally, the knowledge gained was analysed with regard to its transferability to other regions and industrial estates in Germany.

Here  you can find the final report of the “Pro.La-Fellbach” project (in German).