Turns out that good top-soil is important not just for gardeners, but for city planners as well. Topsoil can provide valuable water conservation management services for cities. However, too much urban area is covered with pavement, compacted dirt and other surfaces that, unlike topsoil, do not absorb water well, if at all. As a result, complex rainwater management systems are required to collect rainwater; in fact, a number of B.C.