Rain harvesting in schools – a turning point in environmental awareness and water conservation
Water supply of sufficient quality is an increasing problem in the world. The water crisis in Israel is only expected to worsen as its population grows. Rainwater harvesting in Israel may provide a partial solution to the loss of millions of cubic meters of water in urban areas, which are currently drained into the sewer, and/or the sea. The collection and use of this high quality water to replace "Mekorot" city water is currently implemented in 40 schools and dozens of private homes throughout the country. The dissemination of this idea and its implementation may save significant amounts of water and money for the country, the schools, and the citizens involved. In addition to the physical water saving, an extra benefit in the operation of such a system is the learning of sustainable principles and instilling hope for a better and more environmentally correct future. Moreover, exposing students to the idea and involving them in the processes of planning and managing the system in their school equips them with learning skills and helps them to develop consumer awareness.
The rain harvesting system developed by Amir Yechieli is modest in its dimensions and has a positive cost/ benefit ratio. The system is based on collecting the run-off into plastic tanks with a holding capacity limited to short-term use (as opposed to the large ancient water cisterns used for long-term storage). Repeated filling and emptying of small reservoirs many times throughout the winter can supply up to 90% of the water consumed by a school during the rainy season. The optimal storage volume varies from school to school and is determined by the size of its collecting area as well as by the school's consumption rate. Ideally, the collected amount should last until the next rain (roughly seven consumption days). The water is used for toilet flushing, cleaning, irrigation of greenhouses and indoor planters. During the summer the system could be harnessed for recycling water from drinking fountains and taps, which is used for irrigation of the school grounds.
The water recycling project in schools demonstrates a sustainable use of resources, and allows for an in-depth exploration of fundamental and ethical questions regarding the relationship of humans to their surroundings. Both the physical presence of the water system in the school, and its incorporation into the curriculum (such as integration of the topic into geography and science studies) enables comprehensive discussions regarding the water dilemma in Israel and its possible solutions. The practical management of the system permits children to assess the efficiency of the model they have developed and calculate how much water and money the system has saved their school.
The importance of the initiative
The water crisis entered the public consciousness only after a series of drought years. Furthermore, the distribution and the regulation of water consumption demonstrate a severe lack of long-term planning and correct utilization of water sources by the authorities. The state of Israel exploits a mere fifth of the rain that falls on its territory, and an additional fifth of this rainwater flows in floods to the sea or is drained to the sewer. The remaining three-fifths of precipitation are lost to evaporation.
The economic-political aspect
Schools spend tens of thousands of shekels on water annually, and such a project can save up to two thirds of this cost. The expense of constructing such systems fluctuates between 20,000 and 30,000 shekels, and it can pay itself back within several years. It is very important to assist schools in obtaining this initial sum. Recently, the idea was adopted by the State Department and the European Union, which funded the construction of twelve systems in Israel, Jordan and the Palestinian Authority. This enabled the Arab partners to save water that is so crucial for their even more water-stressed populations and to meet with their Israeli counterparts to the initiative, in order to compare results and ideas.
Expanding the initiative to the students' homes
The opportunity to obtain sufficient water for all household purposes during the winter, as well as high quality drinking water year-round, by rain harvesting systems, is one that appeals to many. It replaces unreliable filtered or bottled mineral water, and thus can save families thousands of shekels annually. Moreover, it reduces the annual production and transport of hundreds of millions of plastic bottles that create severe environmental damage.