Lawn Seeding or Sodding

[Hopper1124]

I have a question, I have a client that has a great front yard, but it has a 25' x 7' dip in the middle. Can I just fill that with topsoil and reseed or do I have to kill off the grass inside the dip and add topsoil then reseed. Not sure On the best way to go about this. I was figuring I need about 2 yards of Topsoil.
Thanks for any help
Hopp

[walker-talker]

Just fill it then seed or sod.

MATT

[shadow]

fill it in and seed it the old grass under the soil will eventually grow through if the soil your putting on top is not to thick