It is evident that consensual management 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, so the 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 time series for some stations with very few field measurements,” said Nandiga.
Now that the data scarcity constraint is being addressed in the Wami-Ruvu and Rufiji basins, inadequate knowledge of the quality and quantity of the available water resources should no longer delay their development for the benefit of the people in these basins. Hopefully the use of a similar system in the other river basins in TZ will follow, as the Ministry of Water is determined to see this happening.
River flow is one of the more difficult variables to measure on a continuous basis, so it is commonly derived by converting daily level recordings into discharge by using a rating curve. Establishing the shape of the rating curve historically requires lots of streamflow measurements. However, in this case the difficulty of accessing the remote station and insufficient funding for a field measurement program meant data was scarce.
To solve this problem, WARIDI used AQUARIUS Time-Series software to redevelop rating curves using a robust conceptual model that requires far less field data. This “hydraulic” approach is based on the premise that the parameters of the rating curve function can be inferred from field observations of river channel properties. Discharge measurements at the station’s control section then serve to calibrate and fine tune the conceptual model.