Dagvattenfördröjning

Dagvattenfördröjning, which translates to stormwater retention or detention, is a crucial concept in urban hydrology and water management. It refers to the practice of temporarily storing or slowing down the flow of rainwater runoff from impervious surfaces like roads, rooftops, and parking lots. The primary goal of dagvattenfördröjning is to mitigate the negative impacts of rapid stormwater discharge into natural water bodies and drainage systems.

When rain falls on impermeable surfaces, it cannot infiltrate the ground and instead flows over the surface, picking up pollutants such as oil, sediment, and debris. This increased volume and velocity of runoff can lead to erosion, flooding, and increased pollution of rivers, lakes, and coastal waters. Dagvattenfördröjning aims to reduce these effects by holding back the water for a period, allowing for a more gradual release.

Various techniques are employed for dagvattenfördröjning. These include green infrastructure solutions like rain gardens, permeable pavements, green roofs, and detention ponds. These methods not only store water but also promote infiltration, evaporation, and biological treatment, effectively reducing the volume and improving the quality of the runoff before it reaches the receiving water. By delaying and managing the flow of rainwater, dagvattenfördröjning plays a vital role in enhancing the resilience of urban environments and protecting aquatic ecosystems.