Plaxis 2D Dynamic Analysis-Water Load on Laterel Boundaries

Dear sir/madam,

I am studying on dynamic analysis on Plaxis 2D for my master thesis. I have two questions:

1) I'm using free field boundaries on the lateral boundaries and compliant base boundary at the bottom of the model. Is it normal to have water loads on the lateral boundaries as you can see on the figure i have uploaded?

2) Does it matter to have closed or open boundaries for drainage in dynamic analysis step?

Thank you, best regards.