Civil Engineering March 2021 | Vol 29 No 2

54 March 2021 Civil Engineering How do you secure sustainable and in- creased access to water and sanitation in the face of stressed water resources? If you had to choose between hydroelectricity or food security through irrigation, what would you do? And what about environmental integrity in the riparian zone with its rich flora and fauna? Or can we find a compromise and manage our river systems in a coordinated way that achieves most of our objectives? Do we accept the inevitable trade-offs? “These questions can only be answered if you have good and reliable water data,” says Bigambo Nandiga, COP for USAID’s Water Resources Integration Development Initiative (WARIDI). “By collecting high-quality water data, analysing it using state of the art methods, and producing accurate information, we can support better decisions on irrigation planning, hydroelectricity development, and other water-dependent sectors.” The absence of a sound understanding of the hydrological processes because of inaccurate, insufficient, or no data at all can lead to overly conservative decisions and lost potential, and quite possibly to resource conflicts. In Tanzania, WARIDI is supporting socio-economic development with effec- tive water data management. Wami-Ruvu and Rufiji basins Accurate information on the quality and quantity of the water resources of the Wami-Ruvu and Rufiji basins is required as a basis for socio-economic development within these basins. The Nyerere Hydropower Project – a proposed 2 100 MW hydroelectricity plant in the Lower Rufiji – and the large potential irri- gation schemes along the Kilombero River are just two examples of important water- related development projects that may impact the socioeconomic development trajectory of the entire Tanzanian nation. The two basins also have critical environmental value in the Ruaha, Kitulo, Mikumi, Selous, and Udzungwa national parks, while providing water supply for vast and fast-growing urban areas such as Dar es Salaam and Dodoma. Pressure on water resources within the Wami-Ruvu and Rufiji basins is increasing to unprecedented levels because of ongoing population growth, food security concerns, and socio-economic development, while climate change is altering the rainfall pat- tern and availability of water resources. It is evident that consensual manage- ment of a basin’s water resources only works across water authorities when based on facts and a solid understanding of the hydrological regime. This, in turn, requires good water data. However, the collection of reliable water data can be difficult and expensive in having to send out personnel into remote and not always easy to access locations. To overcome these hurdles WARIDI installed modern hydrometric instruments in 25 stations to facilitate automatic data collection and processing. This put an end to time-consuming and error-prone manual data processing, and data integrity is no longer an issue for these stations. WARIDI also deployed Aquarius software for time-series data management and analytics, which provides a broad set of tools for effective management, quality control and dissemination. “The program can create accurate and defensible rating curves with a robust conceptual methodology that requires far less field data which has substantially increased the accuracy of the existing water data, as well as the confidence we have in these data. It also made it possible to recover streamflow Supporting development through effective water data management Simon Skey International Account Executive Aquatic Informatics Rufiji Water Basin staff carrying out high flow measurement at Mgeta gauging station using ADCP Hydrologists collecting water data in at Wami-Ruvu basin