Amerongen rainwater-proof
The frequency of heavy rainfall is increasing. During intense rainstorms, the sewer system in the village of Amerongen cannot always cope with the large volumes of water. Limited stormwater drainage capacity, combined with extreme rainfall, can cause streets, gardens and basements to flood. The Amerongen Rainwater-proof project was carried out to minimise the future risk of flooding.
The project covers five sections, four of which are located on the east side of the village. The fifth section involves the old village. In some streets, the municipal authorities are replacing the highly outdated sewer systems. Within the Amerongen East area and the old village, facilities are being constructed to disconnect downspouts from the sewer system. This will reduce the burden on the sewer system, while allowing clean rainwater to directly infiltrate into the soil. This benefits both the sewer system, and nature.
Results
At several locations in Amerongen East, infiltration pipes and swales were constructed to disconnect clean rainwater from the combined sewer system. Rainwater is collected and retained for a longer period before gradually infiltrating into the soil instead of being discharged into the sewer. In addition, outdated sewer systems at several locations in Amerongen were replaced.
The construction of the above facilities will immediately reduce the current combined sewage system overflow onto the floodplains. In the future, such overflow will only operate during extreme precipitation and will consist of rainwater only.
First section
In the northern part of the village, at De Del near the cemetery, the underground stormwater system has been made visible by creating a small waterfall. From this point, rainwater flows into a newly constructed swale with a height difference of approximately three metres. Once the swale is full, the water is conveyed through an underground pipe to the floodplains.
Benches have been installed alongside the swale and the waterfall, allowing visitors to experience the water system. An information board next to the benches explains both the underground and above-ground water systems. Elsewhere in the project area, a water storage reservoir has been constructed. During dry summer periods, the stored water can be pumped out to irrigate trees and other vegetation.
These solutions were developed in cooperation with the Municipality of Utrechtse Heuvelrug and engineering consultancy BOOT. To involve local residents in the project, several public meetings were organised. During these meetings, residents were invited to contribute ideas for making the area more climate resilient. The preliminary design proposals were presented, and residents shared their views on the planned green space improvements associated with the construction of the infiltration pipes and swales. There was also an opportunity to ask questions about the planned works and their impact on the neighbourhood. The final design was presented during the last public meeting.
The Municipality of Utrechtse Heuvelrug subsequently finalised the design plans. The works were then carried out in phases across the different project areas.
Contact person
William Hendriks (projectleider)
BOOT
w.hendriks@buroboot.nl
0318 527600