Presentation from the 2013 World Water Week in Stockholm

Transcription

1 Presentation from the 2013 World Water Week in Stockholm The Author(s), all rights reserved

2 Groundwater Resources Management Support Program Why is groundwater protection important for sustainable sanitation and city planning in Lusaka? World Water Week 2013 Stockholm, September 3 rd, 2013 Simon Kang omba (DWA) & Dr. Tobias El-Fahem (BGR)

3 STRUCTURE OF PRESENTATION Introduction Groundwater vulnerability Concept of groundwater vulnerability Lusaka s vulnerability map Groundwater protection Concept of protection zoning Recommendations for Lusaka Conclusions

4 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: Groundwater Resources of Southern Province Phase 2: Groundwater Resources of Lusaka & surroundings Phase 3: Groundwater Resources Management Support

5 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

6 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/km 2 Sanitation Coverage (considered adequate): 65% Water supply is a mix of groundwater and long-distance surface water (approx. 50:50) Pit Latrine!

7 Workshop on Groundwater Protection and its link to Sustainable Sanitation and Town Planning From the 8th-10th February 2011 the workshop on Groundwater Protection and its link to Sustainable Sanitation and Town Planning took place in Lusaka (Zambia) Convened by the BGR policy advisory group on groundwater (resources and management), Germany, and GReSP Co-funded by GIZ and Co-organized by WASAZA Target group: Zambian institutions, senior staff level Observers from other countries In total 43 participants (hydrogeologists, sanitation experts, town planners) attended the workshop

8 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 Map Program 1:75,000 Lusaka & Surroundings

9 Recommendations for groundwater protection

10 Recommendations for groundwater protection 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. Sanitation systems need to be lined with material preventing leakage of wastewater into the groundwater and seepage of groundwater into the wastewater containment.

11 Recommendations for groundwater protection 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. 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. Water Resources Management Act of 2011 prescribes the establishment of groundwater protection zones. For improved groundwater protection zoning, flow velocities need to be determined through tracer tests.

12 Other proposed land use restrictions 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. No cemeteries to be allocated in these areas No landfills to be commissioned in these areas 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.

13 Other proposed land use restrictions This includes banning of activities like quarrying in the priority areas 1 and 2.

14 Other proposed land use restrictions There should be no active landfills and dumping of wastes needs to be prohibited and compliance enforced.

15 Other proposed land use restrictions 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.

16 Lusaka relies on groundwater Half of the public water supply comes from the ground within the city. Groundwater is vulnerable Pollution happens easily in the karstic aquifer. Without protection water supply is at risk. With the population growth, higher demand and higher pollution will occur. No sustainable city planning without groundwater protection. Conclusions

17 THANK YOU FOR YOUR ATTENTION!

18 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 of vulnerability.

19 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

20 Recommendations for groundwater protection