A literature based study of stormwater harvesting as a new water resource.

Rainwater harvesting is an important new water resource that participates in bridging the deficit in the water resources in water scarce countries. It is not a new technology but it has been practiced in many countries for many years. From a quantitative point of view it makes a positive contribution to the water resources balance. However, the quality of this new water resource was under the subject of this study in addition to the historical and international experiences carried out in stormwater management. Rainwater harvested from rooftops was noted to be much cleaner than that coming from urban stormwater runoff. The water quality parameters in stormwater were examined with a focus on heavy metals such as Cd, Zn, Pb and Cu which are released in low pH values. Fortunately, heavy metals like other ionic bounds and metal oxide bounds are removed by precipitation or co-precipitation at high values of pH.