UN Watercourses Convention-Reconciling “Reasonable and Equitable Utilization” and “Obligation Not to Cause Significant Harm” Principle

Customary international law on transboundary watercourses has evolved significantly
in the past years. A number of international law instruments have been concluded over
the years that have significantly impacted the customary international law on
transboundary watercourses. Cumulatively, these instruments have gone a
considerable way to consolidate the rules governing international watercourses. From
these instruments, emerge two main principles; “equitable and reasonable utilization”
and “obligation not to cause significant harm”. There is scholarship that says that the
two principles can and do exist in harmony with each other. On the contrary, it is
asserted that the two principles reinforce each other as opposed to being in tension
with each other.