If there was a river near you that wasn't advised to drink raw, just like most rivers on earth, could you build a farm next to a river and have a successful harvest of food and weed? Isn't this how the ancient sumerians and ancient Egyptians grew their crops and poppy plants?
Toro,
First, a warm welcome to the Forum. Glad to see you jumping in here.
Now for my late morning scribbling, ...
If you are inherently addressing building a farm for food production, around SHTF aftershock, it depend if Continuity of Government is still in place. If COG is, the answer is No.
The Potomac ?! a waterfront farm ? Even in ideal times, "gentlemen farmers" also had to have $$$.
I learned about SHTF matters and the Chesapeake Bay requirements. A senior official of the Mid-Atlantic asked if his adult son could join my small homestead group. To abbreviate, he told me during a disaster like SHTF with COG in place, no private citizen waterborne craft could enter the Bay. I'm no farmer; once did grow a lima bean in Cob Scouts. I am a net fisherperson. We've got a Zodiac inflatable with nets. Today a file cabinet and additional PC space needed for permits, etc. In a major disaster less permits and no access.
Yes, river access for food production was used in late antiquity. Surely even prior. Some societies of this era did not rely on rivers.About 50 years ago - was not living here then - I learned about this for $35.00 for a book explaining this. At one time $35 had some value. As soon as I finished reading this book, I started on one of the "bibles" on list to read. I could have saver 35 bucks if first I read: "Deuteronomy 11:10. I only read all the holy books for non-"religious" purposes.