www.worldwaterweek.org
Presentation from the
GReSP Groundwater Resources Management Support Program
Groundwater Resources Management Support Program
Why is groundwater protection
important for sustainable
sanitation and city planning in
Lusaka?
World Water Week 2013
Stockholm, September 3rd, 2013
STRUCTURE OF PRESENTATION
Introduction
Groundwater vulnerability
Concept of groundwater vulnerability Lusaka’s vulnerability map
Groundwater protection
Concept of protection zoning Recommendations for Lusaka Conclusions
GReSP Groundwater Resources Management Support Program
Project Framework
Technical Cooperation implemented under the framework of the German-Zambian "Water Sector Reform Program“
Spearheaded by the Department of Water Affairs - Ministry of Mines, Energy and Water Development and BGR
Overall objectives:
facilitate an effective groundwater resource planning and management and
to strengthen the capacities in the Zambian water sector.
Phase 1: 2005 – 2009
Groundwater Resources of Southern Province Phase 2: 2010 – 2012
Groundwater Resources of Lusaka & surroundings Phase 3: 2013 – 2015
Groundwater Management Implementation Components Phase 2 Management Tools • Groundwater Information System • GIS Topography, Hydrology, Hydrogeology • Thematic Maps Hydrogeology Vulnerability • Development of guidelines Hydrogeological Assessment • Monitoring • Groundwater Potential • Groundwater Quality • Pollution risks/Vulnerability Capacity Building • Counterpart Training • Four levels of intervention Advisory and Advocacy • Stakeholder involvement -Technical Forum • Awareness raising
GReSP Groundwater Resources Management Support Program
Groundwater in Lusaka
Lusaka‘s population is estimated to be over 2 Million Population growth: 4.7% p.a.
Increase in population density since 1970 to date from 700 to more
than 3000 people/km2
Sanitation Coverage (considered adequate): 65%
Water supply is a mix of groundwater and long-distance surface water (approx. 50:50)
•
From the 8th-10th February 2011 theworkshop on ‘’Groundwater Protection and its link to Sustainable Sanitation and Town Planning’’ took place in Lusaka (Zambia)
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Convened by the BGR policy advisorygroup on groundwater (resources and management), Germany, and GReSP
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Co-funded by GIZ and Co-organized byWASAZA
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Target group: Zambian institutions, seniorstaff level
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Observers from other countries•
In total 43 participants (hydrogeologists,sanitation experts, town planners) attended the workshop
Workshop on „Groundwater Protection and its link to Sustainable Sanitation and Town Planning
GReSP Groundwater Resources Management Support ProgramMap 1:75,000 Lusaka &
Surroundings
Recommendations for groundwater protection
1. City planners and decision makers in the local authorities and
commercial utilities are advised to use the vulnerability map to prioritize interventions of groundwater protection for different areas.
GReSP Groundwater Resources Management Support Program
2. Sanitation provision must focus on high-density peri-urban areas;
greatest attention to extreme and highly vulnerable areas. In priority areas 1 and 2 sanitation must receive highest importance. 9 Sanitation systems need to be lined with material preventing leakage of wastewater into the groundwater and seepage of groundwater into the wastewater containment.
3. The choice of the sanitation systems to be applied must consider the karstic nature of the underground with the
containment of excreta being the most important criterion e.g. biogas systems, dry toilets and sewerage as long as they provide sufficient protection against leakages.
4. In the highly vulnerable setting of Lusaka, sanitation cannot
remain in the responsibility of the individual household. 9 Lusaka City Council (LCC) as well as the water and
sanitation suppliers must take the matter into their own
hands and provide the necessary resources required for this.
5. Water supply wells should be protected by a zoned approach of
land-use restrictions.
9 Water Resources Management Act of 2011 prescribes the establishment of groundwater protection zones.
9 For improved groundwater protection zoning, flow velocities need to be determined through tracer tests.
GReSP Groundwater Resources Management Support Program
6. Groundwater protection measures in the form of land-use
restrictions should be put in place in city planning, infrastructure
implementation and on-going activities.
9 No cemeteries to be allocated in these areas 9 No landfills to be commissioned in these areas
9 Petrol stations and depots, as well as solvent requiring
industries must not be constructed unless all existing sites can ensure (EIA) that their facilities are safe and do not develop leakages. Storage tanks have to be built with the highest
standard of containment and the adequate monitoring facilities.
Other proposed land use restrictions
9 This includes banning of activities like quarrying in the priority areas 1 and 2.
GReSP Groundwater Resources Management Support Program
9 There should be no active landfills and dumping of wastes needs to be prohibited and compliance enforced.
9 Industrial land use
Where industries are already
located in highly vulnerable zones and cannot be given
compensation and transferred, Zambian Environmental
Management Authority and Water Resources Management Authority need to monitor water effluents and groundwater quality in the area very intensely and work together with the industries to ensure all possible measures are taken to prevent pollution.
GReSP Groundwater Resources Management Support Program
9 Lusaka relies on groundwater Half of the public water supply comes from the ground within the city.
9 Groundwater is vulnerable Pollution happens easily in the karstic aquifer.
9 Without protection water
supply is at risk.
With the population growth, higher demand and higher pollution will occur.
9 No sustainable city planning
without groundwater protection.
GReSP Groundwater Resources Management Support Program
Definition of Vulnerability
The concept of groundwater vulnerability is based on the assumption that the physical environment provides some natural protection to
groundwater against human impacts, especially with regard to
contaminants entering the subsurface environment (VRBA &
ZAPOROZEC 1994).
The fundamental concept of groundwater vulnerability is that some areas
are more vulnerable to contamination than others.
The ultimate goal of a Vulnerability map is the subdivision of an area into several units
showing the
different degrees
Method applied for vulnerability calculation
• PI-Method
• Protective cover (P) and • Infiltration conditions (I)
• PI-method is applicable in Lusaka as it considers the protective cover and the bypass in epikarst environments
• A Karstic environment can show features such as caves, sinkholes, fissures and underground streams. These usually form in regions of plentiful rainfall where bedrock consists of carbonate-rich rock, such as limestone, gypsum or dolomite (like in Lusaka) that easily dissolve.
• Contaminants can easily enter karst aquifers through sinkholes and other epikarst features and spread rapidly over large distances. Natural processes filterting the water are often very low; hence pollution is not treated but merely transferred in the groundwater system
GReSP Groundwater Resources Management Support Program