Namibia water security experience Presented by:. Zelda Scheepers   Namibia water security experience Presented by: Zelda Scheepers 10 July 2017

Namibia Windhoek Total Area 825,615 km2 (318,772 sq mi) (34th) Water (%) Negligible Population 2.459 million (2015) World Bank Capital Windhoek Municipal Area: 5142 km² Service Area: 105 km² Elevation: 1700 m Rainfall: 350 mm/annum Nearest perennial water source over 700 km away Potential evapotranspiration is 3,400 mm

Population Served: Water: around 400,000 – coverage of 99+%. The Basics: The City of Windhoek (CoW) is responsible for water supply, sewage collection and treatment for each of the city’s 22 localities. Population Served: Water: around 400,000 – coverage of 99+%. Sanitation: 75% (300,000 people) waterborne sanitation coverage. Water Supply Overview: The CoW supplies around 30 million m³/annum of potable water (82,200 m³/day). 75% is supplied by NamWater, Namibia’s national bulk supplier from surface water sources. During 2015 CoW sourced and supplied 4% from around 50 boreholes and 22% from the reclaimed water plant, as well as 4% non-potable reuse for irrigation. Financial Performance: The annual net revenue from water and sanitation services in 2015 was N$ 735 million (US$ 53.5 million). The bill collection ratio is 75 / 80%

Climate Vulnerabilities Drought: Reduced rainfall and increased evapotranspiration → reduce available water from surface water sources and groundwater resources → a reduced volume of treated wastewater and water available for reclamation. Industries may be affected which have a knock on effect on the economy. Increased Rainfall Intensity: Potential to damage the catchment areas and increase the siltation of surface water resources. Flooding can directly affect the ability of assets to work. Flooding and increased rainfall intensity can lead to ingress into sewer systems, potentially overwhelming them and hydraulically overloading wastewater treatment plants and polluting of downstream surface water resources.

Best Practice Examples Wastewater Re-use: The (Old) Goreangab Water Reclamation Plant (GWRP) reintroduce treated wastewater, for the irrigation of the golf course, parks, sports fields and cemeteries. This can be expanded even more, and a new Master Plan was completed in 2016 with this view, with 2017 as the first year of implementation. Water Reclamation: The New GWRP, completed in 2002, treats wastewater effluent from the city’s domestic wastewater treatment plant and supplies the city with 5.2Mm³/y or 17% of its water. Reducing Unaccounted-for-Water: Unaccounted-for-water (UFW) in Windhoek is estimated at below 20% and a program has been implemented to reduce UFW with an initial target of 15%. Managed Aquifer Recharge: Windhoek artificially recharges the aquifer to the south of the city and has substantially increased the artificial recharge and abstraction capacity in Windhoek by drilling new injection and deep abstraction boreholes. The managed recharge takes the form of water banking where surface water is “banked” in the aquifer as security against droughts. The current capacity of 480 m³/h will be increased to 1850 m³/h. Waste/Demand Reduction: Windhoek implemented regulations to reduce wastage of water. These measures have successfully reduced demand by an average of 25% in response to the drought. Demand Management through Increasing Block Tariff: Windhoek practices consumption-related, progressive water pricing. Drought Planning: Windhoek has a drought management plan. The latest version has just been launched in May 2017 following the latest drought. It is published on its website. It includes a description of drought severity indicators and an index of the classification of the severity of drought based on those indicators, the impacts and the response plan actions required for each stage of severity.

Implementation Capacity: Challenges Faced Funding: Severe constraints in obtaining the necessary internal funding from large scale capital projects aimed at building climate resilience. Projects need to be favorably “packaged” to attract investors and allow for external and private sector financing. Implementation Capacity: Implementation capacity in particular at GRN level lacking. Given private sector involvement, strong internal (public sector) drivers are essential to ensure implementation of planned projects. Insufficient capacity in this area is a huge stumbling block and often the reason for non- or late implementation. Political Resistance: Over and above, technical and economic feasibility projects need to be “sold” to key political stakeholders to ensure support and the necessary political drive to gain approval for implementation.

The Reality 2015 Central Areas Workshop 2015: NamWater warns that the dams will be empty by end 2016 [75% of Windhoek’s water supply] Impact: Borehole capacity of 15% from 50 boreholes Reclaimed water & non-potable water for irrigation Possible Actions: Increase water supply capacity from boreholes by December 2016 with 1200 m³/h Reducing Unaccounted-for-Water Implementation of Demand Management Measures Challenges: Funding Implementation Capacity Political Resistance

How? Increase water supply capacity from boreholes Change focus from implementation of Managed Aquifer Recharge to implementation of increased abstraction capacity: Drilling of large diameter deep production boreholes Capacity Testing of these boreholes Equipping the boreholes Connecting of the boreholes to the CoW distribution network Waste/Demand Reduction Due to very low inflow to the dams during the 2015/16 rainy season, savings need to be achieved to reach December 2016. Reduce Unaccounted-for-Water Implement Demand Management Measures 25% was achieved

Capacity increase Dec 2015 till Dec 2016 Planned Jan 2016 onwards Boreholes 4.73 Mm³/a 13.71 Mm³/a Reclamation 5.09 Mm³/a NamWater 11.86 Mm³/a 2.88 Mm³/a TOTAL 21.68 Mm³/a

Lessons Learned Reasons for Success Strong leadership Political support Sufficient Funding Buy in from the Public Lessons Leaned Technical and Operational Water Quality Reverse flow Disinfection Bottle necks and over pressure Drilling Project Successful use of probe holes combined with resistivity Political Support Once the crisis is over the support is wanes

Getting Back on Track Implementation of Windhoek Managed Aquifer Recharge System (WMARS) Water banking where surface water is “banked” in the aquifer as security against droughts. Dams to be used at greater risk levels, as security lies in sub-surface storage where evaporation and aquifer losses are negligible. The overall aim is for the aquifer to be able to supply 70-80% of demand when it is full, and then for it to rapidly and fully recharged afterwards. It also improves the water quality. Further benefit: at an overall cost of around N$ 700 million (current implementation phase N$ 300 million), it offers a considerable saving over alternative schemes to transfer surface water from the Kavango River at an estimated cost of N$ 1.79 billion or to desalinate water from the coast.

WMARS Implementation Current managed recharge installed capacity is approximately 480 m³/h (filter and disinfection) Drilling of additional boreholes Infiltration testing of additional areas Protection of the aquifer, ensuring that water is only recharged when the quality is spot on – centralised polishing plant Connecting pipelines and booster stations

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