英语中,后置定语是紧接着被修饰词后面的吗

英语中,后置定语是紧接着被修饰词后面的吗
normal water level ：the water level at the water supply needed to give the required effect capacity in relation to the low water level,including any necessary margins e.g.for ice
比如上面这句中的“needed to give...”是修饰“water supply还是更前面的water level?
pressure tank：A tank containing water under air pressure sufficient to ensure that all the water can be discharged at the necessary pressure
这个句子中，under air pressure...是修饰water还是前面的“A tank”？
像这些后置定语的表达有没有什么方法能辨别？还是只能凭语境和语感？

前面的主语,the water level ,这种情况就是修饰被隔开了,有些句子中间会有些插入语句,独立主格结构,往往难以翻译