Integration of green-blue rainwater management approaches into a planning and implementation tool for BIM-compatability

Due to climate change, heavy rainfall events have become more frequent and more severe. Cities like Vienna are particularly affected by the consequences due to a high degree of sealing. City planning is not in line with “water-sensitive” principles. As a result, the sewage systems are repeatedly pushed to their limits. At the same time, summer heatwaves and dry periods are becoming more intense and longer, putting massive pressure on urban vegetation.

A key aspect of creating climate-resilient cities is therefore integrative rainwater management (RWM) and implementing green-blue approaches. The planning, implementation and operation of more sustainable RWM systems often cause problems for stakeholders due to their complexity. Planning and decision support systems and BIM-compatibility for green-blue solutions are currently missing. A simple and transparent web application for planning sustainable, green rainwater management systems can fill this gap as a stand-alone-solutions as well for BIM-integration.

Solutions for decentralised and integrative green rainwater management are collected and analysed and made available via a web interface which are based on a component database from the software BIM as well as predefined and scientifically elaborated parameter-based calculations for discharge. Complex, interlinked systems of building-related retention solutions (roof and façade greening), rainwater utilisation and infiltration systems are linked together.

The aim is to create a prototype web application for planning integrative, decentralised stormwater management systems. The planning recommendations should respond to the individual project parameters. These include, for example, size and type of the area to be drained, runoff coefficients, the soil conditions and potential infiltration capacity, the available infiltration area, the rainfall measurement and other microclimatic parameters. In addition, the web application is designed to meet the specific requirements of users by taking into account preferences in terms of aesthetics, improvements of ecological and biodiversity status, of microclimate and costs.

Through this comprehensive approach, the planning tool will cover the needs of various stakeholder groups. Compared to hitherto solutions, the intended application represents a massive simplification for all users. This enhances the rethinking of urban design and more resilient urban planning. The spectrum of decentralised rainwater management will be made accessible to a broader public, thereby raising awareness and optimising and maximising the potential of green-blue RWM solutions. The interested public can get basic information and overview, planners have access to a wide range of parameter-based components and complex systems can be planned quickly and easily. This contribution presents a new approach supporting future BIM standards for rainwater retention and green-blue RWM implementation.