Another nightmare, this is way too big for me to imagine. It all looks good to me just the way it is, don't you need someone who knows what they are talking about to sort this out? It would have taken me three weeks to write your description alone.

Adorable house and garden! Great pics!
Are you doing the drainage work yourself? I cringe at the thought of tackling something like that myself. Hopefully you'll get some advice from someone here who has tackled a project like that. I think the old garden looks good, so a variation on it will be good too, I don't see why you can't do wavy beds once the grading is done. I'd just maybe do a tad less waves. It does lend itself to a regular pattern repeated. Or even some type of climbers. Depends on your taste.

Run it down the center of the lawn area, but dig it out and recontour for a slight depression - even 1/2" to 1".

Run a perforated line like a French drain, with the perforated pipe covered with fabric to keep sand out. Fill to the surface with an 80% sand + 20% soil or compost mix. Almost a golf green soil base.

I use sand in lawns many time where I want a French drain effect and no gravel or rock showing. You can sow grass seed into the sandy French drain and it will still work.

It would not be exactly like the images in one album of mine, but you can see how I was using sand. The grass filled back again. The homeowner called a couple of months later to say that the saturated area had firmed up and the lawn grew in.

Here is a link that might be useful: Check out a few drain line images. Click to enlarge if needed.

Thanks to mdvaden for the excellent images & examples! That was exactly the kind of advice I was looking for.

This is a project that has be preying on my mind since the first time I found water in my basement. I knew that I wouldn't be able to afford to contract this out to professionals (as much as I wish I could), so I've been working up to it for the last few years & have come to grips with the "nightmare". Besides, I have a great housemate (big & burly) right now, who volunteered to help me with the digging this spring. :)

Just fyi, yesterday I finished digging out a rain garden on the other side of the house. That side of the yard is graded a bit better and has enough room for the raingarden, so it will me a lot easier to direct downspout water to it. It's been raining today since the wee hours, and I managed to leave for work in a heavy downpour--so I got a good chance to see where all the water puddles & how I can redirect it. :)

Thanks for the responses. I'd love to hear from anyone else that might like to add their two cents!

My pennys: consider the two different types of pipe used for drainage. The less expensive black perforated is great to gather/collect moisture from a wet area. Non perforated piping is used to transport the gathered water to another location. Its usually more expensive than the black but you don't need filter cloth.

Just wanted to drop in a note of thanks for the advice I got on fixing my drainage problems.

I finally bit the bullet on this, and finished potting up all the plants & started digging. Corrected the slope away from the foundation, but left a little bit of a berm along the neighbor's fence so I wouldn't be pulling in ALL of their water too. Dug the trench down the center of the side yard, installed the gravel & PVC pipe sloping down to drain into the front yard. The power company line trimming crew was nice enough to drop off a huge load of free wood chips just as I was finishing up this project--so I temporarily have a wood chip path curving down the center of the side yard until I figure out what kind of path I want to install. :)

Thanks!

Here is a link that might be useful: Almost finished...

All I can say Fiona is WOW! I have total garden envy and really admire the amount of work you've put in to ALL your projects.

Oof! Now, THAT was a project. Great job! And you completed it so quickly; I wish I had your ambition!

Thanks! And just for fun, here's what I did with most of the dirt that I hauled out of the side yard--lawn furniture!. This project is posted over in Garden Junk, the link is below.

Here is a link that might be useful: Lawn Furniture