How is catchment protection organised

A water catchment protection system has been set up, based on the flow speed of groundwater. Around a catchment, three successive perimeters, with a different geographical area according to the local hydrogeology of the exploited table and the nature of the soils, are demarcated.

In these perimeters, the measures of protection are either borne by the holders of water catchment authorisation, or by the SPGE.

Before, specific work costs or compensations due to owners and users of the ground surface were financed by a protection fund supplied by the usage fees and the tax paid by the owners of water catchment in the Walloon Region. This drinking and groundwater protection fund had been set up by the Walloon government.

Now, the usage fee is paid to the SPGE, which takes care of financing catchment protection.

The means obtained thanks to the usage fees are used to improve the quality of Walloon water, whatever the owner and the final consumer.

Water catchment areas

Water catchments are divided up in four categories:

1. The A-category includes the pumping tests, whose duration does not last longer than twelve months, and the temporary pumping operations made during public or private civil works.

2 . The B-category includes water catchments destined for public distribution; for the distribution of spring water, mineral natural water or thermal water in conditioned form; for human consumption; for the manufacture of foodstuffs; for the supply of public installations (swimming pools, baths, showers and other similar installations).

It should be noted that water catchments made by private people for the exclusive use of their household are excluded from this B-category.

3. The C-category includes water catchments that do not belong to A and B-categories, and whose flow rate is higher than 10 m³/day or 3,000 m³/year.

4. The D-category includes water catchments that do not belong to A and B-categories, and whose flow rate does not exceed 10 m³/day nor 3,000 m³/year.

Protection areas


Three big areas exist, where human activity is strictly regulated:

1.  The water catchment area (A I). It is an area of 10m radius around the external limits of the surface installations needed for catching water. This area is mandatory and valid for all water catchment categories, A, B, C and D. This area is justified by the need to exclude any direct discharge in a zone weakened by the cracking of plots affected by the water catchment execution works .

The water producers are responsible for all works carried out inside the water catchment area.

2. The prevention area (A II) is mandatory for all water catchments in the B-category in unconfined aquifers and is optional for water catchments in confined aquifers. This area is justified by the potential presence of any pollutant in the aquifer that could reach the water catchment without being degraded or dissolved enough and leaving no possibility to recover it efficiently.

The prevention area is subdivided into close prevention are (A IIA) and remote prevention area (A IIB). This distinction between prevention areas allows a modulation of the regulations from an area to the other by imposing more severe measures in the area IIA.

I. The prevention area in unconfined aquifer is subdivided into two subareas:

1. The close prevention area (A IIA). There are two possibilities: either a study is carried out to demarcate the area, or no study is carried out.

a. If a study is carried out: beyond A I, the close prevention area corresponds to a transfer time of a pollutant in the aquifer to the water catchment of one day. Close to the installations, its geographical expansion corresponds to the response time needed to put the water catchment out of order;

b. If no study is carried out: for lack of enough data enabling the demarcation of the area IIA as explained above, the area is delimited by a line located at a minimum horizontal distance of 35m from the surface installation (in the case of a well), or by two lines located at minimum 25m on both sides of the surface projection of the longitudinal axis (in the case of galleries).

2. The remote prevention area (A IIB). There are two possibilities too:

a. If a study is carried out: beyond area IIA, that is, between the external perimeter of the area IIA and the external perimeter of the water catchment calling area, the remote prevention area corresponds to a transfer time of 50 days.

b. If no study is carried out: the perimeter of the area IIB can vary according to the nature of the soil, because the flow speed of water will differ. The perimeter of this area will be distant from the external perimeter of the area IIA of:

- 100 meters for sandy aquifers (sand);

- 500 meters for gritty aquifers, or the distance between the stream and the limit of the alluvial aquifer (gravel);

- 1,000 meters for fractured or karstic aquifers (fractured or karstic rock).

When there are preferential flow axes of groundwater flow that feed into the water catchment, the area IIB spreads along these axes on a maximum distance of 1,000 meters and on a width at least equal to the one of the area IIa.

These distances can by revised if a posterior data acquisition allows to establish the area IIB according to transfer times or to the limits of the calling area of the water catchment.

II. In confined aquifer, if a pollution risk exists, the prevention area is the area within which the transfer time is below 50 days in the saturated ground. This area has the characteristics of a remote prevention area.

The SPGE funds studies to demarcate the prevention areas as well as the actions of compliance that need to be carried out in those areas.

3. The monitoring area corresponds to the geographical area of the drainage basin and of the hydrogeological basin likely to supply an existing or potential water catchment. The monitoring area is determined after a public enquiry, and the competent Minister regulates the activities in this area.

The SPGE's role

Files of demarcation of the prevention areas follow an administrative progression in which the SPGE's role is essential. Since April 2000, the SPGE indeed assures the management and the financing of files concerning the protection of drinking water distributed by network.

On the basis of specific programmes submitted by the producers, the SPGE created a protection programme approved by the Walloon government. Within this framework, the producers provide the administration and the SPGE with the projects of prevention areas, usually created cooperatively with the Groundwater Observatory.

The administration and the SPGE examine the studies that lead to the proposition of demarcation of the prevention areas, and give their opinions and potential remarks over these projects to the competent Minister.

After the Minister's consent, the project is submitted for commodo-incommodo enquiry in the municipalities on which the suggested prevention areas expand. Generally, a meeting is then organised between the municipal authorities, the producer and the SPGE, in order to inform the people concerned about the implications resulting from the establishment of these areas, and about the realisation and financing methods of the compliance actions.

It should be noted that the public enquiry, beyond a formal administrative procedure, allows the citizens to express some remarks, but also gives the possibility to bring precise information about the vulnerability of the aquifer supplying the water catchment. One of the effects resulting from the enquiry is therefore that everyone takes part in a protection process through the realisation of a local context.

The municipalities provide the administration with the minutes of the termination of the investigation. The administration examines the potential remarks or complaints and then set the limits of the prevention areas. They finally write the draft order in order to demarcate these areas.

The project setting the limits of the prevention areas, as well as the delimitation order, is then submitted to the Minister, after consulting the SPGE. On the basis of these reports and opinions, the Minister decides whether he accepts the areas and signs the order demarcating them officially.

If the Minister agrees, the administration, the producer, the SPGE, the mayors of the concerned municipalities and the people who made remarks during the commodo-incommodo enquiry are informed. The delimitation order can then be published in the Belgian Official Journal.

As a consequence, the producer may conduct the enquiry that will allow them to identify the actions to carry out in the prevention areas, and to estimate them with a view to the submission of the programme to the SPGE.

The SPGE examines this programme and takes in charge the financing of the actions it agreed with.

The producer pays the SPGE on the basis of a price of € 0.0744 per cubic meter of water produced and on the basis of the amount produced by the drinking water catchment that they exploit during a full calendar year. In return, the SPGE pays for the specific protection measures (studies and actions) of drinking water catchment made by the producer, up to 2/3 of the payment due to the SPGE. The remaining 1/3 builds up a pooled fund, managed by the SPGE and intended to finance either the linear and general measures of drinking water protection on the territory of the Walloon Region, or, under the solidarity principle, specific measures of water catchment protection of certain producers.

Apart from these tools, information, consultation, prevention and human investment remain the guarantee of the success of groundwater protection.