This is a terrible picture of my house, from the top. The blue lines are my attempt at contour lines. The front yard is relatively flat. There is a low area (marked with a red X) in front of the porch. Alongside the house (far right in the picture) the ground slopes down.
Last month we had a nasty weather combination. We had already accumulated about a foot of snow on the ground. Then for two days is was unseasonably warm -- well above freezing -- and it rained a ton. The combination of snow melting off the porch and garage roof and dripping down onto the red X, rainfall, and snowmelt from the yard caused the red X area to flood. We went out every hour and threw buckets full of water out into the yard. It was inefficient and we looked mighty silly - but the water stayed outside and never got onto the porch even though it was within an inch of doing so. Phew!
About the roof. We have a standing seam roof. For the uninitiated, this is a metal roof that allows the snow to slide off of it. When the storm started, the house roof had no snow on it. The porch and garage are unheated, and so there was still a good bit of snow there. The porch and garage roof both empty in front of the porch (our main entry door). Snow often gets "stuck" in the area of the red circle where the two roof angles meet.
I'm trying to think ahead. What would prevent something like this from happening in the future? My idea - not knowing what I'm doing at all - is to hire someone to install a drain where the green circle is. They could run a pipe all along the front of the house and have the outlet be in the backyard, which is several feet lower in elevation. Am I on the right track?
EDIT: There is a drain in the floor of the garage, about where the purple circle is. I don't know where it's outlet is. I don't know of any other drains for rain along the exterior of the house. Like other houses in snow country with metal roofs, we do not have gutters or downspouts.
