App to improve rainwater harvesting

A new smartphone app developed by UN Environment and the United Nations Educational, Scientific and Cultural Organization calculates the amount of rainwater that can be harvested from the rooves of houses, UN Environment reported in April 2019.  

The app aims to support individuals as well as communities, local governments and other actors who are planning to install rainwater harvesting systems in Africa. It is based on actual meteorological data collected from weather stations across Africa. The data is specific to locations closest to the weather stations, which the app presents as the nearest city. 

In many countries, rainwater can be harnessed easily for domestic and agricultural use. Harvested rainwater can also benefit the environment and the ecosystem when used to enhance groundwater recharge and restore vegetative cover. The low cost of rainwater harvesting technologies can be a more attractive investment option in rural areas compared to investing in a main water supply system.   

Opportunities for rainwater harvesting

Rainwater can be collected in relatively simple ways. Rain that falls in ditches, on rooftops or on other surface areas is collected in storage facilities such as water tanks or ponds. This water is stored and used for domestic and agricultural purposes. There are also other ways of rainwater harvesting, such as storing it in the ground where it can be used as groundwater for human consumption or for nature. 

The new app demonstrates opportunities for rainwater harvesting. For example, a person in Turkana county in Kenya can enter her location (Kenya, Lodwar), the length and width of the roof of the house (in metres), the number of family members, and the quantity of water used per day. 

The app returns the estimated amount of rainwater that can be harvested, and the quantity of water for a family. It also proposes the size of the rainwater harvesting system as well as its estimated cost. Simple sketches showing rainwater systems and how to recharge groundwater are also included in the app. Rainwater harvesting systems can be easily constructed using appropriate technology and locally available materials.  

Currently the smartphone application is available for Android (Play Store) system for free. You can download it by searching for RWH Africa Interactive Tool. 

A web version is also available at www.rainwaterharvesting.africa. An IOS (App Store) version will follow soon.

(UNEP/ile)

Read more at the UN Environment Website: 
https://www.unenvironment.org/news-and-stories/story/innovative-smart-phone-app-improve-rainwater-harvesting-africa