This NBS focuses on the delivery additional ecological components withina hard/built engineered approach to water management. They aid thereduction in pluvial flood risk in urban areas and improve the quality ofwater within sewerage systems. The main approaches and benefits of harddrainage flood prevention are:
Considerations in designing hard drainage flood prevention: The dam specifications need to consider sediment trapping behind the dam wall,which can lead to erosion downstream. In addition, altering the riverchannel may lead to a greater risk of flooding downstream, as the water iscarried there faster.
This NBS create important modifications in the environment.
This type of interventions has a very high cost, and is very difficult to get the recovery of the investment.