Implementing integrated water resources management across Tanzania

Tanzania enhances flood preparedness, water allocation and reservoir management with an operational decision-support system

Tanzania faces significant water challenges, including unpredictable rainfall, droughts and limited water management resources, putting pressure on agriculture, food security and overall development. With the added impacts of climate change and a growing population, effective water management is becoming more critical than ever. In a World Bank-funded project, DHI developed an Operational Decision Support System (ODSS) for the Ministry of Water to support informed decision-making, integrated water resources management and knowledge exchange across Tanzania. Key components include a water resources information system and prediction tools for flood forecasting, reservoir operations decision-support, and water use permitting and allocation. With the ODSS in place, Tanzania is set to improve flood preparedness, enhance water allocation decisions and streamline reservoir management, ultimately minimising water shortages and optimising flood control strategies.

Challenge

The Ministry of Water in Tanzania recognised the need for more effective water resources management, with accurate information being crucial. Without reliable monitoring of key hydrometric data like precipitation, temperature, evaporation, flows, water levels, land use and water infrastructure (such as dams), decision-makers faced difficulty in planning for flood control, drought mitigation and water allocation. Due to Tanzania’s diverse regions, coordinating efforts between stakeholders was challenging, hindering efficient water resource management. Additionally, tracking water quality and addressing climate change impacts further added to the challenges, which the Ministry of Water was determined to solve.

Solution

In collaboration with the Ministry of Water, Basin Water Boards and key partners to ensure alignment with national priorities, DHI developed and implemented the Operational Decision Support System (ODSS). The system was designed to enhance knowledge and data exchange, support decision-making and promote integrated water resources management across Tanzania's water-related sectors. The ODSS comprises four key components:

• Water Resources Information System (WRIS): Offers seamless access to up-to-date datasets for effective water resource management across all nine basins in Tanzania. WRIS provides spatial and temporal hydrometric data, near real-time earth observation datasets and allows users to view and download reports, presentations, manuals and explore an electronic atlas.
• Flood Forecasting and Early Warning System (FFEWS): Predicts potential floods in the Wami-Ruvu basin and sends alerts for timely mitigation and emergency response. FFEWS combines weather forecasts, hydrologic models, flood forecasting with data assimilation and a dissemination system to alert stakeholders.
• Water Use Permitting Analysis Tool (WUPA): Supports decision-making for granting and evaluating water use permits, focusing on the Pangani and Rufiji basins. WUPA assesses the effects of water abstractions on the basin’s water balance, empowering informed decisions regarding water use and allocation based on the risk of shortages.
• Dam Operation Support Tool (DOS): Optimises reservoir operations for Nyumba ya Mungu, Mtera and Kidatu Dams. DOS integrates hydrological flow forecasting and operational rules, supporting decisions for water allocation during low flow periods and optimising releases during high flow periods to minimise shortages and reduce downstream flooding.

Additionally, DHI supported capacity building by conducting extensive training to ensure sustainable operation and knowledge transfer.

Results

Implementing DHI’s ODSS solution resulted in the following benefits for Tanzania’s water sector:

• Improved flood preparedness and response through forecasting and timely warnings
• Enhanced water allocation decisions driven by comprehensive analysis and scenario simulations
• Streamlined reservoir operations to minimise water shortages and optimise flood management