Our planning of the topographical changes to the site and how they play into our proposed drainage demanded that we take a look at the quality of existing soil. Our tests involved visually inspecting the layers of soil and filling up holes with water to measure the speed of infiltration. A slow rate would require us to amend the soil in order to install a rain garden, a faster rate would allow greater leeway for planting. We found that water infiltrated quite quickly (as fast as 1″/minute) in the places we checked. We still plan to amend the soil where we will place new plants on the site to give them the greatest chance of survival. One interesting lesson from the day was that we really have no way of knowing what is in the soil prior to digging – unexpected layers are in place from previous designs (rock, geotextile, concrete, mulch) that we may have to alter to allow for the full depth of our drainage solutions.