*4.2.2 Rainwater harvesting*

Rainwater harvesting (RWH) system, also called rainwater collection system or rainwater catchment system, and is a likely viable option to increase water productivity at production system level by using rainwater stored in containers such as tanks or cellars. It has been in use since thousands of years almost anywhere and particularly in the Maghreb countries. Rainwater harvesting is an excellent practice of sustainable water management as it helps to meet the growing demand of water and managing scarce rainfall to an extent and also it reduces flood and soil erosion and may decrease drought risk.

Algeria is facing increasingly more serious water shortage problems because the water is unevenly distributed and less available and the rainfall is uncertain and irregular. Algerian are using rainwater collection from the houses roofs as a solution among other seems good in many areas such as Souk Ahras city.

Morocco—The system, developed and installed by Morocco based NGO Dar Si Hmad, is now the world's largest operational fog-water harvesting system which involves around 600 square meters of mesh netting, seven storage reservoirs, six solar panels and more than 10,000 meters of piping. Fog harvesting is an innovative solution to persistent water stress where fog is abundant. It utilizes a specialized mesh to catches the droplets from the fog and gravity pulls the water down into containers, which slowly fills up to conserve a good water reserve [59].

Tunisia—Water harvesting has been practiced successfully in Tunisia and particularly in southeast part to minimize water deficiency. This country encourages new strategy which is promoting water harvesting techniques (surface runoff water harvesting, floodwater harvesting and spreading irrigation) and sustainable farming practices.

Libya faces very severe water scarcity. Rain water harvesting systems is a way for water conservation in the region; its techniques have been increasingly used to get and collect rainwater, storage and prevention dams, cisterns, contour lines and lunar basins.

Mauritania is an arid country in the Maghreb region which is affected by recurrent climate-related shocks, like the drought that threatens agricultural activities and dries up the water table. Rainwater harvesting (RWH) has proved to be a viable alternative water in the Mauritanian capital (Nouakchott) as it enables the evacuation of rainwater and thus fight against floods.
