You said that your "layer elevations are really high compare to river head".
Do you mean, the top of the layer or the bottom? You should check the
bottom, it must be lower than the head of constant head. Usually this
message means exactly what it says, check each cell bottom comparing with
the head of the constant head cells and you will find the problem, it can be
in just one cell.

2009/5/8 kaviyarasanrajendran@... <
kaviyarasanrajendran@...>

>
>
> Hi all, this is my first mail for visual modflow users group.Know i am
> trying to create a model for hard rock region, regarding this i was tried to
> set constant head boundary condition for selected area. when i trying this,
> software shows 'your CHD head should be greater than your bottom of cell
> elevations', my doubts is here only,my layer elevations are really high
> compare to river head. please give answer for that...thankyou