.- 140 -2. If a wateraourse State is requested by another watercourse State to provide data or information that is not reasonably aveilable, it shall employ its best efforts to comply with the request but may condition its compliance upon payment by the requesting State of the reasonable tiosts op collecting and, where appropriate, processing such data or information, 3. Watercourse States shall eaploy their Lest efiorts to collect and, where appropriate, to process data and information in a mc,nner whiah facilitates its utilisation by the other watercolrrse States to which it is communicated. PART III PLANNED MEASURES Watercourse States shall exchange information and consult each other on ths possible effects of planned measures on the contlition of the watercourse [system]. Before R watercourse State implements or permit6 the implementation of planned measures which may have an appreciable adverse effect upon other watercourse States, it shall provide those States with timely notif ication thereof. Such notification shall be accompanied by available technical data and information in order to enable the notified States to evaluate the poaeible effect6 of the planned measures. Unless otherwise agreed, a watercourse State providing a notification under article 12 shall allow the notified States a period of six months within which to study and evaluate the possible effects of the planned measures and to communicata their findings to it. J&v This article is based on article 11 a6 proposed by the Special Rapporteur in 1987. Lu/ This article is based on article 12 86 propotied by the Special Rapporteur in 1987. - 141 -During the period referred to in article 13, the notifying State shall co-operate with the notified States by providing thorn, on request, with any additional data and information that is available and necessary for an accurate evaluation, and shall not implement, or permit the
**Analysis**
The text appears to be related to the management and conservation of water resources, with a focus on cooperation and information sharing between countries. It discusses the exchange of data and information, notification of planned measures, and cooperation to evaluate the effects of such measures. This suggests that the text is related to the field of environmental protection and natural resources management.

**Category**
Natural resources and environment, International relations