We have a slight slope from the house to the edge of a steeper slope. The slight slope drops 0.5m at a length of 4m. So we need a wooden retaining wall with drainage, approx. 17 to 19m long, posts 1m deep into the ground and wall 0.5m above ground at the end of the slight slope. At both ends 2m length of wall of less height right-angled to cover the slope. Quote per meter please. Job completion not later than 22.11.