David Johansen wrote:
This summer we laid sod in our backyard and we prepped/flattened the
sod underneath, but we were in a rush to try and finish some things up
before it started raining and I guess we walked on it too much before
it all settled because now the ground is fairly uneven and not as
flat/ level as I would like.

Is there a way to level the ground under the grass now that it's
established?

Thanks,
Dave

I assume you mean you want to smooth the surface making it even, not make
it level. Leveling (ie making horizontal) is hardly practical after you
have laid sod.

You could top dress it. Using a friable loam, rake and drag it over the
grass, cover thinly overall with almost none on the high spots but filling
up the hollows and cracks. A heavy log of wood pulled by a loop of rope will
give you a smooth surface and in time muscles too! The grass will grow
through the dressing and form a smooth mat. This is best done during the
growing season otherwise you can get erosion down the hollows before the
grass grows.

David