The Nile River is the main source of surface freshwater in Egypt. Because of the limited share of Nile water to the country, the Egyptian authorities had planned to reuse non-conventional water sources, such as agricultural drainage water and treated wastewater, for irrigation. It is obvious that these two water sources are of low quality. As a result, specific laws were authorized by the Egyptian government for regulating the reuse of these waters for different purposes. Of the most important is Law 48/1982 and Decree 8/1983 which deal specifically with the discharges of effluents in water bodies. The main targets of this law is to protect the Nile River and waterways from pollution. In addition, the ministerial Decrees 256/1994 and 44/2000 were issued to specify quality requirements for unrestricted and restricted irrigation by wastewater.
Water quality index (WQI) has been employed for evaluating the quality category of water of the main drains in Egypt. The results indicated that the values of WQI of most drains of upper Egypt are categorized between very poor and very good, while those of east, middle and west Nile Delta were between very poor and good. This low water quality of most agricultural drains is due to the discharge of polluted effluent into these drains. It has been recognized that the drain catchment is supplied by water from small drains which contain usually very poor quality water. In order to improve water quality of the main drain, it must first reclaim water quality of small drains before discharge into the drain catchment. Constructed in-stream wetland treatment system can be successfully used for reclamation and treatment the water of small drains at a certain point before inflow the main drain. This system has high removal efficiency of most pollutants. It is also easy to construct, requires low investment and low maintenance time and expense. It can be managed successfully by operators having moderate training and by the local community.