Article 18

18.1 Commentary

Article 18 addresses cases where a watercourse state is aware of measures being planned in another state and believes they may have a significant adverse effect upon it, but has received no notification by the planning state. In such an instance, the former is allowed to initiate the procedure provided for under Articles 12-17.While paragraph 1 allows any watercourse state which is in the above mentioned position to request the planning state ‘to apply the provisions of Article 12,’ this expression does not mean that the latter has automatically failed to comply with its obligations under Article 12.301 It could well be the case that the planning state, during the initial assessment of the possibility of the planned measures to cause significant adverse effects upon other watercourse states, concluded in ‘good faith’ that no such impacts would result. This is why a watercourse state is allowed under this provision to request that the planning state takes another look at its assessment, and does not prejudge whether the planning state complied with its obligation to notify or not.302

In order to be warranted such a query, however, the requesting state has to meet two conditions. Firstly, it must have ‘reasonable grounds to believe’ that measures are being planned which may have a significant adverse effect upon it. Secondly, the requesting state must prepare a ‘documented explanation setting forth its grounds’. These conditions, similar to the ones laid out in Article 15, are intended to require that the requesting state has more than a mere apprehension. This extension of the concept of ‘good faith’ demands for a serious and substantiated belief, which seems appropriate given the possibility that the planning state may be required to suspend implementation of its planned measures under paragraph 3 of Article 18.

The first sentence of paragraph 2 deals with the situation in which the planning state concludes, after taking another look at its planned measures as laid out in paragraph 1, that it is not under an obligation to notify (under Article 12). Here, the Convention aims to strike a fair balance between the interests of the parties by requiring the planning state to justify its findings in the same manner as was demanded from the requesting state under Paragraph 1.

The second sentence of paragraph 2 relates to the case where the finding of the planning state does not convince the requesting state. It demands the former to promptly enter into consultations and negotiations with the latter, if deemed necessary by the requesting state. The process of consultation and negotiation has to follow the manner described in Article 17 (1) and (2) – i.e. on the basis of ‘good faith’ and with the aim to reach ‘an equitable resolution of the situation’. Finally, paragraph 3 requires the planning state to refrain from implementing the planned measures for a period of six months – unless otherwise agreed. This provision resembles Article 17(3), the only difference being that here the period starts to run from the time of the request for consultations under paragraph 2 of Article 18.