TC Zambia: Improving the Capacities of Groundwater Protection in Zambia

Report of the project:

• Zambia - Improving the capacities of groundwater management and protection in Zambia

Background:
Groundwater is of essential importance for water supply in Zambia as the generally high rainfalls (regionally varying between 600 mm/a to 1350 mm/a) mainly occur during November and March and river streamflows strongly decrease towards the end of the dry season, with some streams and rivers eventually falling dry. As illustrated by the updated hydrogeological map of Zambia, which was issued by the Water Resources Management Authority of Zambia (WARMA) und the Federal Institute for Geosciences and Natural Resources (BGR), the potential to use and abstract groundwater may strongly differ regionally.

Fig 1: The city of Lusaka with the city skyline on the horizon, viewed from the Great North Road Source: BGR

Many major Zambian cities, like the capital Lusaka, are located close to highly productive limestone aquifers. Nevertheless, Lusaka faces occasional water scarcity as it is considered one of Africa's fastest growing cities, causing an ever increasing water demand. Currently, the local water utility, Lusaka Water Supply and Sanitation Company (LWSC), draws about 40 % of its raw water with high energy consumption from the Kafue River and about 60 % from groundwater wells distributed over the entire urban area. In addition, a large number of inhabitants and industries rely on private boreholes. Water quality at these borehole sites is typically unknown.

Missing Groundwater Protection in Lusaka:
Insufficient sanitation in large parts of Lusaka as well as other sources of contamination (e.g. industrial plants, petrol stations) endanger the groundwater quality within the urban area. Various studies have repeatedly identified impairments of groundwater quality in Lusaka, mainly due to microbial contamination. This, among others, manifests in recurring cholera epidemics. Especially the Lusaka Dolomite, the most productive and important aquifer of Lusaka, is highly vulnerable to contamination, as studies by the former Department for Water Affairs and BGR have shown. Nevertheless, groundwater resources in Lusaka and Zambia in general are hardly protected.

Fig. 2: Groundwater vulnerability map of Lusaka Source: BGR

The Zambian Water Resources Management Act from 2011 provides for appropriate safeguards. With the support of the BGR, an implementing regulation (Statutory Instrument 20 of 2018, Groundwater and Boreholes) has already been issued, which sets minimum standards for the drilling of new wells. These requirements prevent contamination of groundwater in the immediate vicinity of the well. However, more extensive protection requires the designation of water protection zones with concrete specifications on permitted and prohibited activities in these zones. So far, no such protection zones exist and no uniform procedure for the designation of protection zones is regulated by law.

In order to secure the drinking water supply in Lusaka, an expansion of groundwater extraction and the protection of the resource are necessary. Overall, sustainable groundwater management can only be ensured if the collection of hydrogeological data (e.g. measurement of groundwater levels, documentation of borehole profiles) as well as their follow-up, evaluation and publication are guaranteed.

Objectives:
BGR supports the Ministry of Water Supply, Sanitation and Environmental Protection and the technical institutions WARMA and LWSC in order to improve groundwater management and protection in Zambia. The projects aims at achieving three main objectives:

1. Exploration of a future well field to be operated by LWSC and support in the delineation of a groundwater protection zone for this well field in order to improve the quality and quantity of Lusaka's drinking water supply,,
2. Development of training modules on well construction quality assurance for employees of drilling companies and authorities in order to improve the quality of well construction as well as data collection during well drilling (especially borehole completion reports), and
3. Establishment of a digital information platform to easily access spatial, groundwater-relevant data for Lusaka. The platform will allow to incorporate hydrogeological information for evidence based decision making, e.g. for urban planning.

Fig. 3: Overview of BGR activities in Zambia Source: BGR

The project supports both partner institutions building their technical capacities through on-the-job training, workshops and training programs. The technical implementation can draw on extensive previous work, as the BGR has been active in Zambia since 2005 and already carried out investigations in Lusaka in the 1970s.

Methods:
Delineation of Groundwater Protection Zones for a Future Well Field: A comprehensive hydrogeological exploration is conducted to locate a potential site for a new, commercial well field. Previous studies have identified five potential sites for future groundwater extraction in the Lusaka area (see Figure 2). A target area in western Lusaka was selected through the evaluation of field surveys and remote sensing data. Promising sites for groundwater extraction were narrowed down by analysing lineaments, which allowed conclusions to be drawn about tectonic faults. A geophysical survey using electrical resistivity tomography at these sites will provide information on where particularly water-bearing strata are located.

Subsequently, test drillings and pump tests will allow for a final evaluation of the productivity of the potential commercial wells. After the location of the future well field has been identified, tracer tests are planned to determine the flow direction and velocity of the groundwater. Groundwater protection zones for the future well field will be delineated on the basis of all the data collected (see Table 1).

Table 1: Envisaged groundwater protection concept for production wells in Lusaka.

Groundwater protection zone	Extent	Possible restrictions	Methods to determine the extent
I	Direct vicinity of the well field	No activities allowed	10 - 50 meter around the well field
II	Area from which groundwater will reach the well field in less than 50 days and zones of high vulnerability	Proper sanitation; Ban of industrial activities and of pesticide usage	Analysis of groundwater flow directions and velocities; Vulnerability map
III	Catchment (i.e. the area from which groundwater is flowing towards the well field)	General guidelines for groundwater protection, e.g. regarding landfills, infiltration of waste water, etc.	Hydogeological maps and investigations

Finally, the project will support the legal declaration of these groundwater protection zones according to the Water Resources Management Act of 2011.

Vocational Training for Borehole Supervision: Under the leadership of WARMA, training courses for employees of Zambian drilling companies and authorities are being developed. For this purpose, a working group with stakeholders from authorities, associations and drilling companies will be formed to develop and test the course contents. The developed courses will be certified by the Technical Education, Vocational and Entrepreneurship Training Authority (TEVETA) and can then be offered nationwide. Teachers for the courses will be trained as part of the project ("training of trainers"). The aim is to make participation in the courses a prerequisite for issuing licences to drilling companies.

Digital Information Platform: The digital information platform is to provide spatial data in the form of a web-based geo-information system that can be viewed via an internet browser. Corresponding software and a server are already available. Existing maps and data must be prepared for this purpose or made available by the relevant authorities. As soon as the platform is ready for operation, potential users will be taught how to use it in workshops.

Partners:

• Water Resources Management Authority (WARMA)
• Lusaka Water Supply and Sanitation Company (LWSC)

Results of former project phases:

• Groundwater Management with Focus on the Upper Kafue Catchment
• Groundwater Information System and Management Programme for Lusaka
• Groundwater Resources for Southern Province

Literature:

Technical reports

• KREKELER, T. & RAU, S. (2024): Results of the Dye Tracer Test in Lusaka in April/May 2023. - Technical Report No. 2. (PDF, 2 MB)
• BÖTTCHER, S. & FAHLE, M. (2023): Groundwater Chemistry and Flow in Lusaka West and Lusaka East - Results of the groundwater level measurement and sampling campaign of 2021. - Technical report No. 1 (PDF, 11 MB)