Our climate is changing with more heat and longer drought incidents. At the same time, we experience more cases of intense rainfall where cloudbursts are challenging the capacity of city drainage systems.
Solutions to reduce runoff volumes and to improve water quality by filtering sediment and other pollutants are increasingly needed. For some solutions, turf grass is an important component and co-player. Traits such as drought tolerance, salt tolerance and long roots are important characteristics in order to be able to withstand difficult growth condition and secure the functionality of the solution.
Grass swales are often seen as solutions for stormwater retention. During a cloudburst, run off water from roads and other impermeable areas is allocated to the swales where water will accumulate and slowly soak into the soil (infiltration). Most of the year these grass areas are dry.
Cities have many surfaces with limited water infiltration. In a cloudburst situation this may cause problems and pavements with increased infiltration rates are designed with grass reinforcements. The materials used for these constructions are very coarse and almost without organic material.
For both solutions the water quality going into the construction is poor and often contains salt, organic matter and other problematic substances. In an extreme situation it is mixed with sewage.
Green roofs are excellent at stormwater retention and reduce the water runoff by about 50%, thereby delaying the waterflow to the drainage system.
A green roof is designed with a layer of vegetation planted over a waterproofing system installed on a flat or slightly sloped roof. The growth media is shallow, and drought can be an issue.
For all of the above climate solutions, we need robust and resilient grasses that can cope with challenging conditions.
Read more about the green climate solutions in this article in European Seeds INSIDERS