Nad R wrote:
songbird wrote:

it reads like the drainage ditch you put in
works just fine, you need to slope the rest of
the area so that the water flows towards the
center. or you can trench crossways and tie
into the central trench.

for torrents of rain you might consider
adding a low area in to catch the overflow
and that way it has a place to sit while it
soaks in.

i'd not use gravel unless you are putting
in a french drain, resevoir drain or drain
tube with a grate.

also, i'd not mix the decayed wood chips
with the clay. better to leave the clay
undisturbed as much as possible. use the
small really broken down particles in the
topsoil if you have to do something with
it and don't have any other place to go with
it (it would be much better used in a
garden) but i would not put the bigger pieces
of wood chips in the topsoil. that can later
encourage moss or fungus troubles. use them
instead as a garden mulch or along a fence or
under the deck or...

i don't agree with Nad about growing grass
in clay especially if you plan on using it
for a play area for a child. that stuff gets
way too hard when it gets dry. i've got a
broken collarbone in the past from landing
wrong on such a surface.

I mentioned it would be hard during dry spells. However it will still
look just as nice as any other lawn.

I think this depends on what you mean by "growing grass in clay". I have
direct comparisons here between growing grass in clay-based silt, in plastic
clay and a mixture of the two. It is really obvious that (here at least)
grass does not do well in plastic clay and many weeds infiltrate, it does
very well in silt and in a mixture it is intermediate.

This comparison does give some hope though as the mixture can be converted
to useful soil by growing grass on it and mulching in the cuttings. My
understanding is that breaking up the solid clay allows water, air and roots
to penetrate which gives the grass a start and from then on the roots going
into the lumps combined with the mulched grass mixed in gradually breaks up
the lumps. It takes years to change though.

The OP describes the yard as "solid clay" so with that and the drainage
problems I suspect there is going to be much work and/or time to making a
decent lawn that will cushion child's play. I suggest a small play area
covered with bark to make do until the the rest is ready or the child grows
up, whichever comes first.

David