Weighting water interests in spatial plans: principles
Are you the initiator of a spatial plan? Then you will have to write a water paragraph in which the weighting of the water interest is central. We assess this "weighing of water interests" on a number of topics:
Managing water and soil
When choosing a location for a new spatial development or change of function, the water and soil system is guiding. A high/dry site is preferable to a wet, low site. Building on firm soil is better than building on weak soil. Insight into this can be gained from advisory maps of the Water Board and Province.
Hydrologically Neutral Development (HNO).
We apply the principle of hydrologically neutral development. This means that the new water situation must remain at least equal to the initial situation. The compensation rules 'filling = digging', 'paving = compensating' and 'reducing groundwater storage = compensating' are leading.
Prevention of pollution
The Water Framework Directive stipulates that new developments must not cause deterioration of water quality and/or ecology. Preventing pollution is therefore a precondition for weighing the water interests. We are happy to work with you to find ways to improve water quality.
Separating dirty water and stormwater
Dirty (waste) water belongs in the sewer. Clean rainwater preferably drains to the soil (infiltration) or drains to a watercourse. In existing built-up areas we accept a compromise when only a mixed sewer system is present: offering water flows separately to the existing mixed sewer system. We do not accept the construction of new mixed sewer systems.
Reuse > infiltration > buffering > drainage
When disposing of clean stormwater, you use the steps reuse > infiltration > buffering > drainage. Reuse of rainwater is especially interesting for large-scale facilities such as schools and office buildings. The collected rainwater can be used for flushing toilets, for the garden or for washing machines.
If reuse is not possible, infiltration into the soil is preferred. This can be done, for example, via the natural route in the case of a sandy subsoil and a sufficiently low groundwater level, via pebbles or an infiltration system. If this is not an option, rainwater can be buffered in a water storage facility to avoid flooding during heavy rainfall (delayed discharge). A final option is to construct additional open water and drain stormwater into a watercourse.
Watershed Interests
Spatial developments may involve various water board interests. Consider the presence of:
- watersheds and associated zoning;
- watercourses and hydraulic works;
- (pressure) pipes serving the wastewater chain managed by the district water board;
- pumping stations and grinding windmills;
- roads (still within some municipalities);
- properties of the State Water Board.
For proper consideration, it is important to understand the water interests at play in and around your planning area. On www.hetwateradvies.nl (formerly 'the Digital Water Test') you can easily gain insight into this.
Multiple use of space
Use functions can be combined. For example: a wadi can also be designed and managed above ground as a playground for children.
Water as an opportunity
Water is sometimes seen as a problem. However, water can also add value to a spatial development. You can make use of the experiential value of water. After all, many people appreciate a beautiful water feature with accompanying greenery.