The increased hydrostatic pressure from the high river water searches for relief and finds it by under pressure surging into the GW strata mixing with it and changing its make-up with the newly mixed water pushing the ground water up into the pond.
It will be interesting to see if the normal GW is changed by the river water mixing in under pressure during high water periods.
The increased hydrostatic pressure from the high river water searches for relief and finds it by under pressure surging into the GW strata pushing the ground water up into the pond.
I haven't seen evidence of GW changes during high water periods. It is possible that the GW strata (being primarily sand) filters the water and keeps it from modifying the GW to any great extent. It is also possible that the GW flowing through the pond blocks changes coming from run off waters in the river. More likely, it is a combination of these two factors.
Now that there is a test well located in the path of incoming GW, monitoring will answer some of our questions. It will probably create new questions, as well.
