One option for creating additional water storage facilities is storing in underground crates. This is a hidden technology that fits the criteria of sustainable urban planning, which is why it is discussed here. An interesting form of multiple uses of single spaces is realising water storage beneath sports fields. The technical aspects are simple to achieve using storage boxes/bulbs or Aquaflow. The Physical Planning Department of the City of Amsterdam summarised the various options for Amsterdam’s Bijlmerpark.
Sports fields can be integrated into water systems in one of two ways:
- The water storage facility is connected directly to surface water. In this scenario, the water level below the sports fields rises according to the surface water level. This is a simple system to operationalise. Fluctuations in the water levels are limited by the maximum fluctuation of the surface water level.
- The water storage facility is not connected directly to surface water. In this scenario, the water that needs storing is fed in from elsewhere, stored and drained at a delayed pace. This allows for more water to be stored, since greater fluctuations in water levels are possible.
Various materials can be used for storing water under sports fields.
- Aquaflow or a stone-like material with large numbers of gaps. The storage capacity is approximately 50%.
- Synthetic boxes and bulbs. These products are light and offer a high storage capacity of around 95%.