Drain lines certainly work to bring more water. Another option is to build some berms.
Our farm in Kansas is pretty flat. My wife likes to do some landscaping where I have built some little hills. (She is much better than I am at making things "pretty".) A terrace or berm that enhances your view of the pond from the house AND brings more water might also be a good option.
P.S. When you excavate the pond site, you will have a lot of spoils. You will need to place them somewhere on the property. If they are mostly the crappy sand and clay mix that you got on your tests, you will probably need to strip your good topsoil in the location of your spoils, build your spoils piles, and then re-cover with your good topsoil. You could also use some of the spoils material for some interesting landscaping on your property!
