LS2 assigns the meaning connected with water to the adjective rām "high", thus implicitly assigning examples of the singular form such as 1Kg 22:38 where this word renders MT בְּרֵכָה to a misunderstanding or simply a change of meaning of the Hebrew. We follow instead Payne-Smith's lexicographical analysis on the whole while we assume that the semantics of 'pool' here generally refer to elevated sources of rivers and creeks. See form section.
There appears to be little semantic difference between ṭwr and rmh when referring to mountains.