RIWA strives for such a quality of surface water that natural purification is sufficient to prepare impeccable drinking water from it. In line with Article 7 of the Water Framework Directive, this means that the water quality must be further improved, so that the level of the treatment effort can be reduced over time.

The high quality that the drinking water in Europe must meet requires a preventive protection of surface water. After all, purification techniques that must be used to remove impurities present in the raw material are never 100% effective. In addition, certain purification techniques can lead to new chemical transformation products. The surface water should therefore be taxed as little as possible with substances that do not occur naturally.

To achieve this goal, RIWA-Rijn, together with the IAWR, continually uses its (political) influence to bring the importance of a clean river to the attention of politicians, governments and policy makers in water management and industry. It does this on behalf of the 4 member companies (Oasen, PWN, Vitens and Waternet), thus ensuring an efficient approach to common interests.

Under surface water the RIWA understands the rivers, all above-ground streams that directly or indirectly come out on the rivers, the peripheral lakes and the IJsselmeer.