Flooding, along with related storms, is the most important natural hazard in Europe in terms of human and economic loss  and the intensity of flood events has grown in the last years. In urban areas, the waterproofing of soils is incrementally increasing flood risk due to the presence of roads, industries and houses. The intensity and the frequency of flood events will increase in the next years due to global warming and the consequent change in the global water cycle. The resulting increased flood risk poses challenges to society, physical infrastructure and water quality.
Floodable parks can be designed to control flow rates and decrease flow peaks by storing excess floodwater and releasing it slowly once the risk of flooding has passed. They are innovative sustainable urban drainage systems that can play a particularly important role in mitigating potential impacts caused by surface run-off water from rain, flash floods, or from small and medium sized water courses (URBAN GreenUP).
Corktown Common Park, Toronto, Canada (UrbanToronto, image George Broen College). Source: https://urbantoronto.ca/news/2014/07/waterfront-toronto-officially-opens-corktown-common.
In this context, the implementation of nature-based solutions, such as floodable parks, instead of traditional grey infrastructure, can provide numerous benefits such as ecological restoration and biodiversity benefits (e.g., shelter for aquatic birds) , leisure and recreation spaces for better human health and wellbeing, and support to water cycle (water storage and reuse) .
For example, the park Le Jardin de Niel in Toulouse was designed with multiple functions such as i) leisure for open and public use with rest areas, picnic areas, and playgrounds, and ii) flood prevention using Flexbrick (open or wide-seamed ceramic tiles) to favour soil drainage, preventing drainage water loss, and reducing the impact of floods caused by heavy rain (Urban Nature Atlas).
Another good example is Enghaveparken – Climate park that has a 22.600 m3 water reservoir to handle Copenhagen’s current and future challenges with water. The rainwater is stored and used for watering plants and trees during dry spells and can even be used to clean the city streets. At the same time, the rainwater is handled above ground in the multifunctional reservoir and a dike. The park offers opportunities for recreation, exercise, and sensuous experiences .
While appropriate modelling and relevant indexes would be needed to properly plan and design a floodable park, tailoring them to various contexts (see e.g., ), solutions and models can be considered largely available on the market and mature to be implemented everywhere (Technological Readiness Level 8-9).