We're about to level our front yard. It will be partly sown with grass, and partly planted with trees & shrubs, though it may not be completely relevant to this question. What is a suitable slope to gently drain water away from the house? I think one of the tradespeople I spoke to suggested a 1 in 65 slope would be adequate, which by my calculations would be a drop of roughly 15mm for every horizontal metre. Is this about right, not enough, or too much?
Also, I had a go at pulling a string taught from one side of the yard to the other. Holding my spirit level against the string didn't really work very well for working out what was level. What is the best equipment for determining what's level?
I think I have a small spirit level that can attach to a string (from a picture framing kit) which might be better, though I don't know how accurate it will be (I can calibrate it against my big spirit level probably).
Background info: we have high rainfall sometimes in the winter, though the soil should have reasonably good drainage qualities (no clay). The size of the yard isn't very big. The max distance from the house to the edge of the yard is probably about 7 metres.