*4.2.1 Improved sewage systems*

Currently, more than half of global population in the world are living in urban areas. In 2050, more than two-thirds of the global population will live in cities [51]. Therefore, economic development accompanied by rapid urbanization increase the use of freshwater resources and may increase also competition for water between cities and agriculture [52] and thereby produce more wastewater. Therefore, it is necessary to treat sewage before disposing it off in a water body as it can cause serious public health concern and also threat aquatic life. Improved and responsible sewage systems along with treatment of wastewater at site and at treatment facilities, are among some of the tools and techniques which help to protect and improve water quality. As such, the component wastewater reuse (for irrigation and other purposes) is emerging as an established water management practice in several water-stressed regions of the world and particularly in the Maghreb region.

Algeria—As stated earlier that water consumption in Algeria is further aggravated due to economic grow, urbanization and climate change which are all main drivers of increasing water demand in irrigation and industrial uses. The reuse of treated wastewater for irrigation (the largest consumer of water) is a priority of the state. In 2005, Algeria allowed use of treated wastewater effluent for irrigation purposes [53] and signed 5 years contract with the SUEZ Company for the management of drinking water supply and sanitation in the greater Algiers area. The contract was renewed for five years in 2011, then for two years in 2016 and finally for three years in 2018.

Morocco—Improved Sewage Systems could contribute considerably to the reduction of 'water stress' and 'water scarcity' in Morocco as part of an Integrated Water Resources Management (IWRM) approach, focusing on the component wastewater reuse for irrigation and other purposes. The development of reclaimed domestic wastewater reuse projects has emerged as a potential non-conventional resource to satisfy the increasing demand for water [54]. On the reuse of treated wastewater, only 12% are currently recycled. This rate increased to 22% in 2020 and may even reach about 100% by 2030 [55]. In 2017, SUEZ are providing Morocco with several wastewater treatment plants and has completed construction and installation of the Anti-Pollution System on the East Coast of Greater Casablanca in Morocco.

Tunisia—Tunisia is a water-scarce country, and water supply security challenges are predicted to be exacerbated by climate change in the coming years [56]. Improved Sewage Systems is a great way that Tunisia practiced for several years as part of an Integrated Water Resources Management (IWRM) approach to satisfy water demands for irrigation and industrial uses. In 2017, the number of operating wastewater plants in Tunisia were 119, producing a volume of dry sludge of 175,000 m3 /y. Tunisia is, therefore, faced with the challenge of finding secure solutions for the recovery and/or disposal of sludge generated from wastewater [57].

*Water Scarcity Management in the Maghreb Region DOI: http://dx.doi.org/10.5772/intechopen.103788*

Libya—Today Libya is the 20th most water-stressed country in the world. Reuse of treated wastewater was mostly designed in Libya to reduce the water scarcity especially in the irrigation sector. There are around twenty-three wastewater treatment plants distributed all over the country. Nevertheless, only ten are working and in operation [58].

Mauritania—The Mauritanian authorities recently inaugurated a new rainwater collection system as part of a sanitary sewerage network for the city of Nouakchott. This new sanitation network is built by the Chinese company CTE, which aims to enable the evacuation of rainwater and avoid the catastrophic situation that Nouakchott knows whenever there are heavy rains or floods.
