There is also two different types of Ignimbrite ,Unconsolidated...

There is also two different types of Ignimbrite ,Unconsolidated or Lithified.
Do you or the company know what type lays under the river ?.
And what about tension cracks ?.
If the entire length of the river is just Lithified then little water would seep through ,but if there is tension cracks the water would seep through to each brine layer ,and if the Ignimbrite is unconsolidated the water would seep through anyway.
So who is baseless here ?.
Always good to get the facts correct is it not.
My opinion is the water is seeping through ,most likely through tension cracks ,being that the brine is in separate layers.
Time will tell I guess.