01/06/2016 - 31/12/2018
- KWR Watercycle Institute
- Gemeente Rotterdam
- Gemeente Rheden
- Gemeente Den Haag
- Hoogheemraadschap Delfland
- HoogheemraadschapSchieland en Krimpenerwaard
- Evides Waterbedrijf
Underground storage and recovery of rainwater in urban areas
Urban areas are increasingly facing flooding due to intense rainfall, as well as water shortages resulting from longer periods of drought. The current solutions are based on discharge and external supply, which are often expensive and not sustainable. How can we retain rainwater in the subsurface of urban areas longer and more effectively? And can we then subsequently make use of this water?
Field Factors is working together with different water managers, companies and institutes in the Urban Waterbuffer project (UWB), which investigates how can rainwater in the urban area can be held longer and more effectively in the subsoil and recovered for later use.Two pilots sill be implemented in Rotterdam and Rheden.
Need for space
The space needed for water retention and infiltration in urban areas is limited. This results in conflicts with other uses of space or in the implementation of costly solutions. With the Urban Waterbuffer (UWB), rainwater in urban areas can be purified and retained for longer, without conflicting with other spatial functions. The UWB uses deeper aquifers to infiltrate, store and extract rainwater through wells. The purpose of the project is to explore whether this solution can make a significant positive contribution to preventing flooding and improving water supply in urban areas.
In the first phase of the TKI- UWB project, the location, the water balance, the preliminary design and the projected costs of actually installing a UWB system has been identified for four cases: Spangen-Rotterdam, hNI- Rotterdam, Rheden and The Hague. The results show that, particularly in the case of the targeted locations in Rotterdam and Rheden, a UWB could make a concrete contribution in the short term to the discharge of surplus rainwater and thus to flood prevention. The aspects requiring particular attention are the speed with which the peak precipitation loads can be infiltrated into the subsurface, and the pre-treatment of the rainwater with a view to preventing clogging.
Pilot case: Spangen, Rotterdam
The stored rainwater in Spangen, Rotterdam will be used as a source of high-grade freshwater to replenish a pond and to irrigate artificial turf fields at the Sparta Stadium. These applications would likely cover a large part of the annual costs related to the depreciation, maintenance and management of the pre-treatment, infiltration and recovery.
Pilot case: Rheden
In Rheden, no use of the infiltrated water is envisaged at this moment, but the potential benefits are related to the limited surface space required, and to the relief of the municipal sewerage system.
Currently the definitive design and the implementation of pilot systems in Rotterdam and Rheden is on going. The operation of the systems will be monitored within this project.