Catching rain in Bratislava
After recurrent floods of the River Danube in the twentieth century, the City of Bratislava has built the infrastructure to face expected floods for the next 100 years, but this will not be enough to make the city resilient against frequent and heavy rainfalls. One of the most immediate solutions is to implement measures of increasing water retention, which can be through green infrastructure, making soils more permeable, or through grey infrastructure, which contains and reuses, or channels surplus water. While municipalities can do this in public spaces, they are often restricted when it comes to private properties.
So, Bratislava has recruited its residents. In 2016 the city created a subsidy for sustainable water management installations. Private organisations and households can apply to build water reservoirs and rainwater gardens, small green roofs, permeable pavements, etc. The subsidy always covers 50% of total costs of the installations, up to a maximum amount of €1,000 per application. In addition, applicants receive consultation on their project’s implementation and dissemination provided by the city of Bratislava.
After a slow start in 2016, with six completed projects, the initiative has picked up in recent years, with more than €37,000 invested in different projects in 2019. This year, due to Covid the budget was cut, and the total sum of €20,000 will be invested. Most applicants used the subsidy for purchasing and installing rainwater catchment tanks or drainage systems, and reusing the collected water for irrigation. One fifth of the projects created green roofs. Others replaced impermeable surfaces with permeable materials.
Putting heads together for fresh ideas in Dresden
While people in Bratislava are worried about rainfall, Dresden residents have the heat to worry about and despite ongoing renovation of the building stock, many poorly insulated buildings leave residents vulnerable to extreme temperatures.
Experts, such as representatives of the building industry, urban development experts, scientists and researchers, and 178 residents put their heads together to study the issue and find solutions, building a HeatResilientCity.
With data and the residents’ feedback in hand, experts used computer simulation to analyse potential solutions, and residents weighed in to select the ones they preferred.
Putting the expertise of scientists and the expertise of residents together, Dresden developed an inclusive process that meets residents needs and implements effective solutions to improve their wellbeing.
As residents were involved in the process, they understood the importance of the measures that were put in place and were more likely to implement them. This is especially important, since some measures involved behavioural change, for example opening windows at night to create crosswind.
Most citizens indicated a preference for solutions that would create shade and add green spaces and water elements to their living environment. So, housing companies have to take green spaces and extra shade into consideration in current and future open space development. The first trees will also be planted this autumn. A flowerbed has been introduced in the area to also improve biodiversity, and an additional flowerbed is already being planned.
Locals can now refill their bottles at four ‘Refill’ stations. These are shops and stores that have signed up to the ‘Refill’ national initiative, offering people to refill their bottles for free in their establishments.
Read Bratislava’s full case study | Read Dresden’s full case study
*These case studies are part of the Covenant of Mayors collection of case studies and have been presented today at the SDG 11 Day during the United Nations Economic Commission for Europe‘s (UNECE) Sustainable Cities Week. At the same event we presented the Urban Adaptation Support Tool, which takes cities through all the steps needed to develop and implement an adaptation strategy and refers to valuable guidance materials and tools.