Member States shall establish surveillance monitoring programmes to provide information for:

• supplementing and validating the impact assessment procedure detailed in Annex II,

• the efficient and effective design of future monitoring programmes,

• the assessment of long-term changes in natural conditions, and

• the assessment of long-term changes resulting from widespread anthropogenic activity.

The results of such monitoring shall be reviewed and used, in combination with the impact assessment procedure described in Annex II, to determine requirements for monitoring programmes in the current and subsequent river basin management plans.