I would agree with you if two situations were present: (1) this wasn't a small stream that is barely a more than 6-12" deep for its entire run and (2) if there actually were information on hydrology available. Surprisingly, there is little, except for two NJDEP reports on the Papakating watershed that devote one sentence to "phosophorus loading". I do plan to expand the Papakating Creek article and think (a) there are more resources for such content and (b) there a larger exposition on course, watershed, hydrology, geology content would be more appropriate. Further, as MOS eschews short sectionsMOS:PARAGRAPHS says "Short paragraphs and single sentences generally do not warrant their own subheading", it would be inadvisable per the MOS layout guidelines vis-à-vis their application for GA evaluation to start creating short sections. I would venture to say the current combination of this information in one sentence, given the nature of the article and its subject, is entirely appropriate.