At the new headquarters of Fugro, an international geo-data specialist, in Nootdorp, rainwater has been part of the design from the very first sketches. Not just on the roof or around the building, but across the entire site. cepezed designed the headquarters, BoschSlabbers the garden and Fugro's own engineers the water system for their office. We asked hydrologists Mark de Kwaadsteniet and Maurice Shorachi about their experience in the design team.
An integrated water system like this is becoming increasingly important. Heavy downpours are more frequent, while fresh water is growing scarcer in many places. In Nootdorp, salinisation of the deeper soil layers adds another factor. The question is not only how to prevent flooding, but also how to hold on to rainwater as long as possible and reuse it.
looking ahead
According to Mark de Kwaadsteniet, looking ahead is crucial. "A new building will stand for at least fifty years, and by 2076 the climate will look very different." That is precisely why Fugro did not want to add the water system to the design later, but to think about it from the very beginning.
Hydrologists being involved in a design this early is not a given. Often they only come in once the site layout is largely fixed. That means major decisions about the building, the paving and the landscape have already been made, leaving less room to make water a genuine part of the design. This time it was different. When designing their own office, they were involved from the outset.
an integrated water system
The result? Together with the designers at cepezed, a system was developed that captures, purifies, reuses and returns rainwater to the soil as much as possible. As a result, the new site can ultimately hold water longer than before.
This approach fits the ambition for the headquarters: BREEAM Outstanding. One of the requirements is that a heavy downpour of 70 millimetres must be handled on site without causing flooding. The green roofs house retention crates that together store 156 cubic metres of water. When heavy rain is forecast, they can be emptied automatically.
The water then flows to the Urban Rain Shell.
De Kwaadsteniet: "This is a shell reservoir with purifying minerals. It is a sustainable technique for cleaning water before you reuse it or store it in the soil. The minerals bind oil, among other things. At Fugro, the reservoir sits underneath the new car park."
His colleague Maurice Shorachi adds: "It's a whopper. The Urban Rain Shell has been used before in streets, but not at this scale. In our car park, paving blocks sit on top of the shells. The shell reservoir can hold an entire rain shower, with part of the storage feeding the greywater circuit and the rest draining out through infiltration into the deeper sand layers. A membrane wraps around the shell layer so the water can be held. Fast High-Volume Infiltration (FHVI) wells then infiltrate the purified water into the deeper soil layers. This needs a pump, because the seepage conditions in Nootdorp mean you cannot simply get the water down into those deeper sand layers."
