It is a borehole and no the tidal movement make's no diff... to it as it is over two hundred feet from the river.
I am right near the mouth of the river so slit and weed would all play apart in problems of getting water to run.
Even a pipe line keeping it free of crabs snails and so on .
The river is over 400ft wide at full tide and splits into two at low.
I will shot some levels at some time just to see the fall over 100 yards or less.
I am starting to lean to wind unless someone can turn the tide so to speak.
Free life