An example of a large-scale, multi-year trial to collect data on water levels and discharges in small- to medium-scale canals as well as rivers in the context of dry land irrigation was carried out as part of the global iMoMo Initiative (www.imomohub.org). The latter was supported by the Swiss Agency for Development and Cooperation and was part of a drive for innovation in data acquisition, management and exchange, and an overview to help to address global water resource challenges in the context of population growth and increasing climate uncertainty. The device is currently in use in communities in Tanzania, Kyrgyzstan and Uzbekistan and is valued by local stakeholders because it allows incontrovertible water level readings and thus helps to ensure compliance with on-farm community-based water allocation rules.
In addition, an Android app for smartphones has been developed for measuring water levels and discharges based on an optical method that uses a mobile phone camera. The app provides a non-intrusive, accurate and cost-effective measurement method. The process of setting up a new site should ideally be conducted by experts and include measuring the cross-sectional area at maximum flow and the relative distances between four markers on both sides of the shoreline. Once a site is set up, even a non-expert can carry out a measurement in under a minute.  What is more, the App allows seamless data transmission to a dedicated cloud database via GSM/Wifi/SMS. The database can be accessed using a web application in a browser (see https://discharge.ch). The web application allows easy data visualization and data analysis. The app has been deployed in Tanzania, Uganda, Kenya and Ethiopia as well as in parts of Central Asia and is currently undergoing continued pilot testing in selected basins there.
Despite the attractiveness of technologies such as those mentioned above, key lessons from the global iMoMo Initiative have shown that several important preconditions need to be in place for crowd-sensing campaigns to be successful in the sense that they can fill existing data gaps and thus help to improve stakeholders’ decision-making at different water resource management levels. As an example: 1/ clear visions need to be formulated by local stakeholders concerning the usage potential of non-traditional data; 2/ stakeholders from government agencies often show reluctance to promote and adopt these technologies due to non-compliance with national standards and agency underfunding; 3/ proper workflows need to be established, including data collection protocols; 4/ a stringent quality assurance and control process (QA/QC) needs to be put in place; 5/ a dedicated service should be made available to monitor data-collection efforts in a consistent fashion and chase up citizens who fail to deliver data as agreed.