I have had these survive two winters. Note these are unlike our native Arisaemas which can take quite a bit of water. I don't believe it is moisture that is the problem but the getting of air. In the winter they cannot take standing water and will rot. Wet clay will also suffocate them and start the rotting process. I have high clay soil and this is what I did. I used a post hole digger to create a deep hole. I then put in a well draining soil mix. At least 50% sand with lots of humus. I added some bone meal too. I filled to within 5 inches of the top. I then put in one inch of sharp sand and then covered the bulb with sharp sand. They put out long roots that will easily go through the 1 inch of sand into the better soil below and around the bulb. I then covered with the native soil amended with humus and a bit less sand than I had put in the hole. This way water seeping into the soil will have a hard time at first, then hit the sand and go right past the bulb and into the faster draining soil below. If I had filled the hole to the top with sand it would have resulting in surface water running directly into the hole and then pooling at the level of the bulb as it tried to move into the less porous soil below. It is the relative porousity of the layers that determines where the water pools. A quarter inch layer of clay at the surface over the winter would keep the bulbs much dryer. Of course this all depends on your having a site with good drainage. If the location is a swamp your bulbs are would die anyway. Note that I gave a couple plants to several neighbors and they just planted them straight in the ground and have had perfect survival. Their locations however were naturally more sandy. I also found that too much shade reduces their ability to survive the winter. They just cannot store enough food or something. Make sure you do not plant to deeply. They are not good at penetrating lots of over laying soil. It sucks up their resources even if they do make it to the surface and sometimes they actually open their leaves and flowers underground. I had planted 6-8 inches and had this problem. I planted at 4 inches and it was no longer an issue.

There is a drainage easement at the front of our property and an easement to the side where we would route the drain pipes. If you were to take a rectangle, our home sits about 25 feet from the Northeast property line. The hill is on this side as well. To the far left of the rectangle there is a 35 foot drainage easement. This is where we would have to route the water. It is a lot of work involved for us, that is why we had hoped our neighbor would do the right thing and just reroute her pipe to flow onto her own property and not ours.

If you decide to modify the clay with sand, remember you'll be working it roughly 50-50 and it adds up. A thousand square feet of clay to remove and replace, four inches deep, is twelve heavy cubic yards, so it's good to avoid carting stuff away. As a rule of thumb, think of sand for drainage and organics (tons of it!) for growth. Two separate goals. If you do go the French rubble drain route and use an imbedded tube, look into local conditions concerning using weed barrier/landscape fabric to guard against finer materials seeping around the gravel/rubble. It can get in the way of drainage, even at what might seem to be a super slow rate. Here, in our very arid ground, I wrap a perforated three or four inch plastic pile with sunscreen when I bury it in the fill, so if the fabric/pipe clogs the fill might still drain and vice-versa.

I was thinking of using the french drain as a replacement for the catch basin. It would serve the same purpose... collect the water in one place before it can be drained away. I was also kind of thinking it might look nicer having the exposed gravel for the french drain than the catch basin with just dirt around it. You're probably right though. The french drain is a lot more work to serve the same purpose and with possibly less capacity. I'm not sure how to calculate the capacity of a french drain but some really rough math makes me believe that the french drain is gonna have half the capacity. Doesn't your argument against french drains still apply to catch basins though? It's still possible to overwhelm the catch basin if it's undersized? Maybe it's just easier to under-size a french drain? What size catch basin should I be using? Your use of double negatives (unlikely and not) has me a little confused. :) Are you saying that two 4" pipes IS likely to be overkill, or that two 4" pipes IS NOT likely to be overkill? Later on it seems like you're advocating for using the two pipes. All the basins I initially saw with 2 outlets had the outlets on the opposite sides of each other. I figured I would either need have one outlet facing the correct direction and use two 90 degrees elbows to get the other pipe facing the correct direction, or put both outlets perpendicular to desired direction and then use one elbow on each side. I was hesitant to use so many elbows. I read stuff about using 45 degrees (or less) if possible to prevent the water from slowing down. Should I not be worried about that? Some more searching and I found this basin (http://www.sprinklerwarehouse.com/NDS-Drainage-Catch-Basin-p/nds-1800.htm) which lets me choose the sides I want the outlets. Having one face the correct direction and the other only being 90 degrees off seems better.