Looking for help to model basin drains

    

I need to model a basin under a machine.

Water must flow towards the holes (circles) and not towards the center rectangle cut out.

I'm not sure how to start it.  I've made a few attempts but keep getting stuck.

I ''ve only use surfacing a few times and I don't use loft too often.  So it's a learning opportunity.  I usually make machine parts.

Any ideas?

SolidworksSurfacing