INTERNATIONAL CASE STUDIES - AFRICA
CASE STUDIES: BOTSWANA, BURKINO FASO, CAMEROON, ETHIOPIA, LIBERIA, NIGER, SENEGAL, SOMALILAND
BOTSWANA |
CLIENT: |
Department of Water Affairs, Republic of Botswana |
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PROJECT: |
Maun Groundwater Development Project
Phase 1: Exploration and Resource Assessment |
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LOCATION: |
Maun, Botswana
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The joint venture of Vincent Uhl Associates, Inc. and Water Resource Consultants (Pty) Ltd. (WRC) was contracted by the Department of Water Affairs, Government of Botswana to conduct a groundwater resource assessment and development feasibility study for a 5,000 square mile area in northwest Botswana with the objective of securing a safe sustainable source for the town of Maun to the year 2030. The study area is on the fringes of the Okavango Delta, one of the largest inland deltas in the world. The study was initiated after a major dam project proposed by Snowy Mountain Engineering Corp (SMEC) of Australia on behalf of the government was terminated after a critical review by the IUCN (International Union for the Conservation of Nature). The study area is primarily in and on the fringes of the Kalahari Desert. Prior to the study, freshwater resources were thought to be very limited and confined to near perennial and seasonal water courses.
VUA and WRC headed the project team which was comprised of 30 technical experts in the fields of remote sensing, vegetation analysis, geomorphology, structural geology, surface water hydrology, hydrogeochemistry, isotope studies, geophysics, hydrogeology, geology, artificial recharge, economics, cost engineering and ecology.
The project resulted in the identification of several new groundwater sources (aquifers)
that are being utilized for supply to Maun and the region well into the 21st century.
Principal Project Components:
- Groundwater exploration using airborne geophysics (magnetic and electromagnetic);
satellite imagery interpretations and surface geophysical studies to identify areas for
exploration field drilling.
- Groundwater resource investigations through the installation of 50 test wells. Aquifer
pumping tests were run on 46 wells completed in the Kalahari Sands.
- Two deep bedrock test wells were installed to depths of 1,000 and 247 meters to
evaluate groundwater development potential and water quality conditions in deeper
bedrock aquifer systems.
- Groundwater development feasibility and sustainability analysis through aquifer modeling; recharge analysis; and groundwater-surface water interaction evaluation.
- Supplementary project activities included: artificial recharge feasibility studies; isotope studies and seismic monitoring.
Download PDF of the Phase 1 Executive Summary
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CLIENT: |
Water Resources Consultants (Pty) Ltd. & Department of Water Affairs
Republic of Botswana |
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PROJECT: |
Maun Groundwater Development Project
Phase 2: Resource Assessment and Wellfield Development |
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LOCATION: |
Maun,
Botswana |
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Vincent Uhl Associates, Inc. was retained by Water Resources Consultants (Pty) Ltd. from 2001 to 2004 to assist in the Phase 2 Maun Groundwater Development Project. This Project Phase involved the siting and installation of two production wellfields to provide water to the town of Maun and surroundings. UHL provided technical expertise in the areas of aquifer recharge assessment; drilling specification development and well design; modeling; groundwater sustainability assessments; and hydro-geochemical analysis.
We also developed a Wellfield Management Plan including operational water quality and quantity monitoring parameters.
Download PDF of the Phase 2 Final Report
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CAMEROON |
CLIENT: |
Engineers
without Borders |
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PROJECT: |
Pro
Bono Assistance to the University of Pennsylvania |
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LOCATION: |
Northwest
Province, Cameroon |
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Vincent Uhl mentored engineering students from the University of Pennsylvania during two assessment phase evaluations of potential water supply sources for village water supply systems.
Mr. Uhl assisted students in the villages of Kop and Gundom in the Northwest Province in the evaluation of potential spring sources that were ultimately developed for a permanent piped water supply system.
In the assessment phase, springs were identified; flows measured and water quality samples collected and analyzed. After the collected data were analyzed, 2 springs were selected in each village for development and piping systems were mapped in the field and planning proceeded for coordination of system installation which were accomplished on subsequent trips.
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ETHIOPIA |
CLIENT: |
Habesha Breweries and IFC |
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PROJECT: |
Evaluation of Environmental and Social Risks Related to Increased Groundwater Use:
Expansion of the Habesha Breweries Facility |
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LOCATION: |
Debre Birhan, Ethiopia (2018 to 2019) |
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Click to see larger version
Uhl & Associates, Inc., and our local partners, Aquacon Engineering, PLC, completed an evaluation of environmental and social risks related to increased groundwater use for Habesha Breweries, Ethiopia.
Habesha Breweries, established in North Shewa Zone south of Debre Birhan City with an initial capacity of 0.4 million hectoliters per year (MHL/year) and has been in operation since July 2015. Habesha Breweries is planning to implement an expansion program with a proposed increase in production capacity from its current 1.0 MHL/year to 4.5 MHL/year. The corresponding anticipated water use will be 2 million cubic meters per year, or 5,500 cubic meters per day (m3/day).
The study area is located just to the west of the major regional surface water divide between the Awash River and Blue Nile River basins. The principal rivers in the study area are the Beressa and Chacha Rivers, both of which flow northwest and are tributaries to the Abay River. The Beressa River drains the northern and eastern portion of the study area, the Chacha River drains the southern and western portion of the study area. The Facility is located in the Beressa watershed close to the divide between the Chacha and Beressa River basins.
Thirty (30) boreholes were inventoried within a 10-Km radius of the Facility which range in depth from 60 to 320 meters, with static water levels from 2.3 to 153 m, bgs, and estimated well yields from 2 to as high as 70 liters per second (lps). Eight shallow hand-dug wells and 25 springs were also inventoried.
Principal Objectives and Activities
- Assessment of groundwater use projections for the area within a 10-Km radius of the Habesha Facility over the next 5 to 15 years given the planned increase of water consumption by Habesha Breweries, the City of Debra Birhan, Debra Birhan University, Dashen Breweries, local villages, and for (known or proposed) increased industrial and commercial use.
- Assess potential environmental and social/community risks and opportunities associated with the increased groundwater extraction.
- Look into the potential for improving water management and reducing consumption within the brewery operations at Habesha, as well as any current or future initiatives to reduce consumption at the local, regional and federal level.
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ETHIOPIA |
CLIENT: |
Stantec (Formerly MWH) and USAID |
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PROJECT: |
USAID A&E IQC — Water Knowledge Management |
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LOCATION: |
Ethiopia (2013 to 2016) |
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Uhl & MWH formulated an Opportunities and Limitations for Small-Scale Irrigation Using Shallow Groundwater Projects to support the goals of the Government of Ethiopia to move 6 million households into food security and improve livelihoods of small farmers through small-scale irrigation using shallow groundwater.
The objectives of this project were to develop:
1. An awareness of the opportunities and limitations for small-scale irrigation using shallow groundwater, and
2. The need for planning and management on a watershed basis so that the groundwater resource is developed sustainably.
In this context, UHL developed the “Irrigable Land Potential (ILAP) Calculator” as a technical planning tool to assess available quantities of shallow groundwater for small-scale irrigation and develop realistic estimates of the potential land area within a watershed that can be sustainably irrigated. The calculator quantifies the available groundwater based on a percentage of precipitation, reserving a percentage for natural resource (environmental) flows, and accounting for current and future groundwater use in the basin.
The ILAP Calculator was applied to two Pilot Basins (watersheds), the Gerbi and Tefki Area with some illuminating results demonstrating the value of the ILAP tool.
As a precursor to applying the ILAP Calculator, several studies were carried out to gain an understanding of the conditions in and available data for each basin. These studies included:
1. The development of mapping products utilizing Digital Elevation Models (DEMs) and satellite imagery (Landsat 8 platform). DEMs were used for generating watershed boundaries, slope maps, and ground topographic contours. Satellite images were used for under- standing the land use/land cover patterns. A precipitation map was generated by interpolating data from nearby weather stations with records available from the past two decades.
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2. A Field Reconnaissance, which involved:
(a) An inventory of a subset of representative water points;
(b) Field water-quality of testing of delivered water from the water points with functional water systems; and
(c) Short-term pumping tests on selected hand-dug open wells.
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LIBERIA |
CLIENT: |
World Bank Liberia Water Sanitation Program (WSP) & Liberia Department of Public Works |
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PROJECT: |
Phase 3: Urban and Semi- Urban Water Point Sampling Project |
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LOCATION: |
Monrovia, Liberia (2011) |
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UHL & Associates, Inc. in association with the University of the Free State, South Africa and EDEN Preferred Water Services of Monrovia, Liberia sampled 202 water points in the capital city of Monrovia. The collected samples were analyzed for:
- Field parameters (collected at water point): Electrical Conductivity (EC), pH, Temperature (T), Oxidation Reduction Potential (ORP), and Dissolved Oxygen (DO).
- Microbiological Parameters (analyzed in field laboratory in Monrovia): Heterotrophic plate counts (HPC), Total Coliform, and E-Coli.
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Inorganic and Organic Chemical Parameters (analyzed at the
University of Free State analytical laboratories in Bloemfontein, South Africa): Anions [Cl, SO4, NO3, F, B, PO4]; Cations [Ca, Mg, Na, K]; Metals [Al, As, Cr, Cu, Fe, Mn, Pb, Zn]; and TOC.
Principal Activities:
- Identifying a subset of 200 water points from a dataset of 1000+ water points to represent the range of source types including hand-dug wells (protected and not protected), drilled wells, city supplied standpipes and kiosks.
- Developing recommendations for short, mid and long-term water quality improvement.
- Organizing workshops to educate involved government agencies and interested non-government agencies.
- Sampling the 200 water points and training locals on relevant sampling procedures, quality control.
- Preparing maps showing Total Coliform and E-Coli contamination, and Inorganic and Organic chemical parameters.
Download PDF of the Case Study
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NIGER AND BURKINO FASO |
CLIENT: |
USAID and Winrock |
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PROJECT: |
RISE II – Niger & Burkina Faso |
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LOCATION: |
Niger and Burkina Faso |
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UHL & Associates, Inc. is working with Winrock International to provide technical assistance in groundwater resources assessment, sustainability evaluations, and capacity building. UHL developed working relationships with Maradi and Zinder Universities Geology Departments for Commune Level water point inventories, assessments, and hydrogeologic analysis. Some of the principal areas of focus have been:
- Field survey planning and coordination.
- Communal-level water point assessments with water-quality sampling and field/laboratory analysis; water-point physical condition analysis; and needed repairs/replacements.
- Regional and commune-level mapping of principal aquifer and surface drainage systems.
- Commune-level groundwater balance development and sustainability analysis for present and future water-supply planning.
- The initiation of groundwater level measurement programs at the commune level for tracking water levels seasonally by commune members.
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NIGER |
CLIENT: |
Millennium Challenge Corporation (MCC) and Stantec |
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PROJECT: |
MCC Niger |
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LOCATION: |
Tillaberi; Dosso; Tahoua; and Maradi Regions (2018 - present) |
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UHL & Associates has been providing technical input to Millennium Challenge Corporation (MCC) & the Millennium Challenge Account (MCA) is the areas of:
- Groundwater resource development feasibility.
- Groundwater sustainability and an overview of the principal aquifers in the four project regions.
- Irrigation feasibility and constraints in semi-arid settings.
- Livestock Markets water systems design and costing assessments.
- Site visits and training of MCA staff.
- Base maps, and drainage maps preparation for project analyses
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SENEGAL |
CLIENT: |
Natural Resources Consulting Engineers (NRCE), Stantec and USAID |
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PROJECT: |
USAID Acces Project Under the WADI IQC |
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LOCATION: |
SENEGAL —Tambacounda, Matam, Ziguinchor, Sedhiou, Kolda, and Kedougou Regions (2016 to 2019) |
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Principal Project Components:
- Evaluation of eight existing village water supply boreholes (installed under an earlier USAID project in southern
Senegal circa 2012) in preparation for commissioning:.
- Borehole diagnostics downhole camera inspection and water quality testing for well screen biofouling and chemical incrustation potential.
- Step-drawdown and constant-rate pumping tests to evaluate well performance and efficiency.
- Dynamic downhole camera logging during pumping tests to assess the degree and locations of sand particulate matter entering well screens during pumping.
- Pumping test analyses and determination of long-term sustainable borehole yields.
- Development of Multiple Use Water Services (MUS) Action Plan approaches for 50 communes (500+ villages) in
Senegal. Training of student groups from the Geology Department of the University of Dakar and field training workshops for the water-point surveys.
- Development of a groundwater recharge analysis for the country at large, utilizing local studies based on the Chloride Mass Balance method and other models; the WHYMAP model global data set, and percentages of precipitation based on hydrogeologic and climate settings. Recommendations of conservative groundwater
recharge values for planning purposes for the 50 communes where MUS Action Plans are being developed.
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CLIENT: |
NRCE and USAID |
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PROJECT: |
Groundwater Recharge Analysis for Senegal: USAID Acces Project under the WADI IQC |
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LOCATION: |
SENEGAL (2016 to 2018) |
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Recharge to groundwater can be estimated from field-based, analytical, and numerical methods. UHL conducted an analysis which identified and summarized the findings of both local and global precipitation and groundwater recharge studies for areas in Senegal. Using estimates from the various studies and experience in similar climatic and geologic environments, average annual groundwater recharge estimates were developed for communes in six regions. Conservative groundwater recharge values were recommended for use in groundwater planning, allowing a reserve for ecological water needs. The local and regional studies included the following methodologies:
- The Chloride Mass Balance (CMB) approach.
- The Water-Table Fluctuation (WTF) method.
- Thornthwaite-Mather Water Balance (TMWB), a water-balance spreadsheet approach that takes into account monthly precipitation, evapotranspiration, soil moisture, etc.
- Numerical modeling methods.
- Application of the WHYMAP model global data set developed by Döll, P. & Fiedler, K. 2008. Global-scale modelling of groundwater recharge. Hydrology and Earth System Sciences, 12, 863-885.
- Applying percentages of precipitation as recharge based on studies in similar hydrogeologic and climate settings.
Data for the period from 1981-2010 indicates an increase in precipitation from south-to-north. The range is from >1000 mm/yr in the south to <200 mm/yr in the north which reflect very dry conditions with commensurate limits on groundwater recharge.
Download Report
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SENEGAL and NIGER |
CLIENT: |
Stantec (Formerly MWH) and USAID |
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PROJECT: |
USAID A&E IQC — Water Knowledge Management |
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LOCATION: |
SENEGAL and NIGER (2015 to 2016) |
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The Sahel is a priority region for USAID, and Senegal and Niger were selected as the pilot countries for a Field Study to evaluate solar rural groundwater based water systems. Both countries rely heavily on groundwater for rural water supply, with boreholes completed in low-yielding basement rock aquifers as well as in higher-yielding unconsolidated and semi-consolidated sedimentary aquifer systems, of local and regional importance. Production Boreholes are at the heart of infrastructure for groundwater based water supply systems, and represent large investments. Boreholes can operate efficiently for up to 25 years and longer with proper design/construction, operation, and timely maintenance. On the contrary, life cycles are much shorter for boreholes that are poorly designed and constructed and/or poorly operated or attended to during operation.
80 systems were evaluated in Senegal and Niger. Borehole diagnostic tools that were used to assess these param-
eters and identify the causation of borehole failures included:
- A review of borehole performance records (pumping rates and water-level drawdown).
- Downhole camera inspection to evaluate the physical appearance of the water and condition of borehole cas-
ing and screen.
- Water-quality testing to identify presence of bacteria and chemical constituents associated with bio-fouling
and precipitation blockage of well screens.
A project workshop was conducted at the conclusion of the project and involved a 1-day seminar session followed by a 1-day field trip to view a solar pumping system set-up and borehole diagnostic techniques.
Findings:
- Primary source of well failures in Senegal was due to sand pumping.
- Poor well design and materials.
- Biofouling, iron precipitate buildup.
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SOMALILAND |
CLIENT: |
Hargeisa Water
Authority
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PROJECT: |
Assessment of City of
Hargeisa Wellfield
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LOCATION: |
Hargeisa, Somaliland
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The Hargeisa Water Authority has an exceptionally challenging mission to keep the water supply flowing into Hargeisa, the largest population center and seat of government in Somaliland. This hillside metropolis of over 300,000 people obtains its water from a wellfield located in the Ged Dheeble valley about 20 kilometers distant from the city.
UHL was contracted by WorldWater Corporation to evaluate the wellfield, and the distribution system from the wellfield to the City. The City's water supply system was installed by the Chinese Government in the early 1970's and expanded in 1986-88. The system was designed to deliver 8,000 to 10,000 m3/day (2 to 2.5 million gallons per day). Water extracted from twelve production boreholes is pumped through two twin underground 300 mm diameter pipelines over a 20 km distance and 260 m elevation to in-ground storage tanks overlooking the city.
Due to damage to the system during civil war in the late 1980's, only six production boreholes were operative at the time of the study. Our evaluation involved an analysis and testing of the six production boreholes; an assessment of requirements to reactivate the 6 boreholes that had been in operation for over a decade, and the outline of a program for additional groundwater exploration in nearby basins. We also outlined the elements of a program to evaluate recharge to the aquifer system supplying the city, and initiated a water-level and water-quality monitoring program for the water utility.
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