TASK DEFINITION: In this task, you are given a sentence in Spanish and your task is to translate it into English. In translation, keep the numbers and capitalization (capitalize only the first word of each sentence and name).
PROBLEM: Se trata, en lo esencial, de aplicar el principio de subsidiariedad.

SOLUTION: In essence this means applying the principle of subsidiarity.

PROBLEM: Así es, aunque los miembros de la organización son los Estados de la Unión y no la UE.

SOLUTION: This is the case, in spite of the fact that it is not the EU, but only the Member States, which belong to the organisation.

PROBLEM: Ahora bien, la cuestión de los derechos o impuestos por la utilización del agua es una cuestión que, en virtud de las normas de subsidiariedad, son los Estados miembros quienes tienen que decidir.

SOLUTION:
However, the question of taxation or charges for the use of water is a matter which, under the rules of subsidiarity, should be left to the Member States for decision.