Groundwater: Solution To Ghana’s Rural Water Supply Industry?

GROUNDWATER: SOLUTION TO GHANA’S RURAL WATER SUPPLY INDUSTRY?
P. Gyau-Boakye and S. Dapaah-Siakwan
Water Resources Research Institute (CSIR), P.O. Box M.32, Accra, Ghana
Published in The Ghana Engineer, May 1999
Reprinted with GhIE permission by the African Technology Forum

Rural communities in Ghana are defined as those with less than 5,000 inhabitants. On the basis of the 1984 population census (the latest census in Ghana) (ATF Editor’s note: at the time of this writing, the 2000 census had not been performed yet), there are about 55,967 rural communities representing 68% of the total population of the country. Traditionally, these rural communities have relied mainly for their water supply needs on sources which range from dug-wells, ponds, dug-outs, streams and springs to rainwater harvesting from roofs. Most of these sources particularly those based on surface water resources are polluted and are the main sources of water-borne diseases so common in the rural areas.

It therefore appears that the solution to the problems of traditional rural water supply systems lies basically in the efficient utilization of groundwater and efficient management of aquifers, hand-dug wells and boreholes. This is because groundwater is not only feasible but also the most economic source of potable water due to the dispersed nature of the rural settlements. Presently about 52% of the rural inhabitants have access to potable water mainly from groundwater sources. To achieve 100% rural coverage by the year 2020 a huge capital outlay of about 1 billion dollars is required. Most of these rural water supply systems are to be based mainly on groundwater resources where available.

According to the Preliminary Report of the 1984 Population census of Ghana, the rural communities (viz. below 5,000 inhabitants) form about 68% of the total population. Table 1 gives a summary of the classification of the rural communities in Ghana.

Community Size	No. of Localities	Size of Population	% of population
Below 200	46,063	1,796,763	14.6
200-499	5,891	1,855,452	15.1
500-1,999	3,495	3,185,951	25.9
2000-4,999	518	1,519,301	12.4
Total	55,967	8,357,467	68.0

Apart from a few of these rural communities which are very close to or within the environs of urban centres, most rural communities are small and scattered over a large number of settlements. Following the “Water Resources Sector Studies”, commissioned by the Government of Ghana in 1969-70, it became the official policy that for the supply of potable water, communities below 500 inhabitants are to be helped to construct hand-dug wells. Supplies to communities of 500-2,000 in population are to be by means of hand-dug wells or boreholes fitted with hand pumps, whereas communities of population between 2,000 and 5,000 are to be supplied by means of pipe-borne systems. While some of these pipe-borne systems are/or to be based on surface water sources, most of them are/or to be based on groundwater resources. Where these technologies are not feasible, rain catchment, spring sources and simple ways of harnessing surface water from dams are to be tried. It is apparent that as a policy, the rural water supply scheme are to be based largely on groundwater resources. Those communities which have not yet benefited from these policies still rely on the traditional sources for their water supply needs. These sources include dug-wells, ponds, dug-outs, springs, ephemeral streams and rainwater harvesting from roofs.

The climate of Ghana which is of primary importance in understanding the spatial and temporal distribution of surface waters is influenced by three air masses namely, the South-West Monsoon, the North-East Trade Winds (Tropical Continental Air Mass) and the Equatorial Easterly. The warm but moist South-West Monsoon which originate from the Atlantic Ocean and the warm, dry and dusty Tropical Continental Air Mass (Harmattan) from the Sahara Desert approach the tropics from opposite sides of the equator and flow towards each other into a low pressure belt known as the Inter Tropical Convergence Zone (ITCZ) [1]. The slow and irregular north-south oscillations of the ITCZ gives rise to the regime of wet and dry seasons. The wet season in the southern sections of Ghana is characterised by two main rainfall regimes, i.e., double maxima whilst the northern sections experience single rainfall regime in a year. The extreme south-western portion of Ghana is the wettest part of the country which receives more than 2000m of rainfall a year (Figure 1). Rainfall which mainly recharges the aquifers generally decreases towards the north and south-eastern sections of the country. The driest part of the country is found in the south-east coastland plains where the mean annual rainfall is about 800mm.

Mean monthly temperature over the country never falls below about 25^oC while open water (pan) evaporation is generally high and ranges from about l200mm per year in the south-west to more than 2600mm in the north. Relative humidities are high on the coast and are generally between 95% and 100% during the night and early morning. These can reach low values of between 20% and 30% or less in the north when the area comes under the influence of the dry Tropical Continental Air Mass (Harmattan).

The country is underlain partly by what is known as the Basement Complex which comprise a wide variety of Precambrian igneous and metamorphic rocks. These crystalline rocks cover about 54 percent of the country (Figure 2). They can be further divided into subregions on the-basis of geology and groundwater conditions. These consist mainly of gneiss, phyllites, schists, migmatites, granite-gneiss and quartzites. About 45 percent of the country is underlain by Palaeozoic consolidated sedimentary rocks locally referred to as the Voltaian Formation and consist mainly of sandstones, shale, arkose, mudstone, sandy and pebbly beds and limestones. Both the Basement Complex and the Voltaian formation have little or no primary porosity, hence groundwater occurrence is associated with the development of secondary porosity resulting from jointing, shearing, fracturing and weathering. This has consequently given rise to two main types of aquifers which are the weathered zone and the fractured zone aquifers.

The remaining 1% of the rock formations are associated with aquifer formations and are made up of Cenozoic and Mesozoic sediments which consist of unconsolidated alluvial sediments, beach sand, red continental deposits of mainly alternating limonitic sand, sandy clay gravels, marine shale, limestone and glauconitic sandstone.

In the pre-colonial era, before Ghana came under colonial rule in 1844, individuals, trading, mining and timber companies and small communities were responsible for their own water supplies. These sources of supply ranged from dug-wells, ponds, dug-outs, streams to rainwater harvesting from roofs. In the case of hand-dug wells, the interested parties or communities developed their own traditional techniques or methods of siting the wells. The wells were usually dug through overburden and weathered rock material and were up to 6m deep. During the dry season when the wells were not yielding, they were abandoned and other sources of water were resorted to until the aquifers were recharged in the rainy season.

From about 1900 the colonial government assumed some responsibility for public water supply in the urban and rural areas due to periodic droughts, population growth and concentrations into larger communities. Consequently, by the turn of the century, a Public Works Department was formed to investigate urban water supplies. Due to frequent drought in the semi-arid northern territories, the Geological Survey Department was requested in 1920 to assist in offering advice on where to site wells. In an effort to deal with the magnitude of water supply problems in northern and the south-eastern parts of the country (the driest areas of Ghana), a water supply division was set up in the Geological Survey Department in 1937. Among the division's tasks were to investigate new sources of supply, whether from ground or surface sources, and to advise medical officers and political administration personnel in well digging, lining and maintenance and the sanitary precautions to adopt against pollution.

In 1944, a Department of Rural Water Supply separate from the Geological Survey Department was set up to take sole charge and deal more effectively with the water supply problems in rural areas. It provided water from wells, tanks, and other small sources in addition to training and supervising native administration staff. Where the rural communities were large enough it provided piped supplies. The piped supplies were based on mechanically drilled boreholes. The progress and failure rate of groundwater supplies in the dry season became a source of concern to the government to the extent that it decided in 1951 to have the situation reviewed. To this end, a consultant was invited from the United Kingdom to advise on the work being done by the Department of Rural Water Supply, the groundwater potentialities of the country and the need to invite tenders for drilling by contract. Between 1952 and 1959 the efforts of the Department of Rural Water Development were supplemented with contract drilling placed with private drilling companies as had been recommended. In addition to the efforts of the Department of Rural Water Development, other agencies like the Department of Community Development of the Ministry of Social Welfare and Community Development and the Department of Agriculture also assisted with rural water supply. The technologies used were mainly hand-dug wells, with or without hand pumps, Henderson Boxes for the development and protection of springs, rainfall harvesting from roofs, infiltration galleries, dug-outs and small dams [2].

After independence in 1957, a number of changes occurred in the institutional set up for water supplies in the country which culminated in the setting up of the Ghana Water and Sewerage Corporation (GWSC) in 1965. The GWSC by the Act establishing it (Act 310), has been empowered to be responsible for the provision, distribution, conservation and management of water supply development and installation, and to co-ordinate all activities related to the water supply industry. The policy of GWSC is to supply potable water to rural communities based mainly on groundwater sources. Groundwater is considered not only feasible but also the most economic source of rural potable water supply. The advantages of groundwater as the main anchor or pillar of Ghana's rural water supply development project are numerous [3]. Firstly, there are aquifers which underlie geographically large areas of the country which can be tapped at shallow depths close to the demand centers in response to the dispersed nature of the rural settlements. Some of these aquifers have modestly been assessed and their characteristics are fairly well known. Secondly, water stored in aquifers is almost protected naturally from evaporation, and well yields are in many cases adequate, offering water security in regions prone to protracted droughts as experienced in the northern parts of the country. Thirdly, with aquifer protection, groundwater has excellent microbiological and chemical quality which require minimal or no treatment. Lastly, the capital cost of groundwater development as opposed to conventional treatment of surface waters is relatively modest and the resource lends itself to flexible development capable of being phased with rising demand.

Table 2 gives a summary of localities and their population and the corresponding main sources of water supply on the basis of the 1984 population census. It can be estimated from both Tables 1 and 2 that about 50.5% of the rural population depend on surface waters such as streams, rivers, lakes, ponds, dams and dugouts. These sources are usually heavily polluted and are the main causes of water borne diseases so common in the rural communities. Based on the same estimates, only about 0.05% of the rural population depend on rainwater harvesting due to the unfavourable annual rainfall pattern in many parts of the country. About 40.7% depend on boreholes and wells whilst about 0.7% rely on springs for their water supply needs.

Table 2: Localities and their Populations in 1984 by Main Sources of Water Supply and by Regions (source: [4])
L = Localities/Communities and P = Population

It is observed from the climate of Ghana (Figure 1) that the rainfall is not uniform in terms of its temporal and spatial distributions. This means that there is a period of surplus water and a period of water deficit in the streams and rivers. The annual rainfall as mentioned earlier decreases towards the north and south-east of the country. These factors point to the fact that many streams, particularly, in the north and south-east may not be perennial. Most small streams which feed many rural communities apart from the possibility of being polluted cannot even do so on sustainable basis throughout the year. Likewise, rainfall harvesting cannot be done all year round due to the rainfall pattern. This is a serious limitation since the storage facility required for harvesting rainfall for use by a rural family throughout the year is economically not affordable.

There is the need to find alternative sources of water supply for the rural dwellers which is self sustaining. Groundwater has been found to be sufficient both in quantity and quality for most rural communities. It is therefore not surprising that the percentage of the rural communities which depend on boreholes and wells has increased substantially since 1984 as the Government and the Non-Governmental Organisations (NGOs) have embarked on large scale drilling of more boreholes and wells. However, it has to be emphasized that the drilling rigs and the pumps are expensive and require foreign currency which is usually scarce in the Third World countries. In 1986 about 7,800 boreholes had been drilled in the various geological formations. There were in addition about 9,500 hand dug wells and temporary pits in weathered rocks and in alluvial sands. These boreholes and wells which provide good quality drinking water are rapidly replacing the usually polluted traditional surface water sources.

Even though hand-dug wells may be among the cheapest means to provide potable water for the rural dwellers, it is realized that 54% of the country is underlain by crystalline rocks (Figure 2) which make hand digging difficult. It is also quite difficult to dig deep below the water table, hence hand-dug wells tend to dry out in the dry season.

11,500 boreholes have been drilled nationwide and about 60,000 hand-dug wells have been constructed. This represents a total coverage of about 52% of the rural population as compared to 41% in 1984. To achieve 100% rural coverage by the year 2020 a huge capital outlay of about I billion dollars is required. This proposed investment was projected from the following estimates. For localities with population less than 2,000 in 1995, water points (boreholes and hand-dug wells fitted with hand pumps and serving 200 persons) required were calculated and costed. Model system per capita investment costs for groundwater and surface water were calculated and adopted for localities with population between 2,000 and 5,000 in 1995. The 1995 and 2020 populations were estimated from the 1984 census figures. For details of the cost estimates, readers are referred to the Strategic Investment of Ghana [5]. Most of the funds are expected to come from the Government with donor countries and organisations making substantial contributions. The Government hopes to derive part of its contribution from privatizing the urban water supply industry. The Government's drive towards privatization of the urban water supply systems should not be seen only in terms of generating funds to support the rural water supply schemes, but also to enable the Government to concentrate efforts on the provision of potable water for the people of the rural areas.

The groundwater resources of the country have been fairly well assessed for some geologic formations in terms of borehole yield, static water levels and water quality [6]. There is therefore the urgent need for the efficient management and utilization of the nation's groundwater resources since all indications point to the fact that it is going to be the bedrock of the rural water supply industry.

The Ghana Water and Sewerage Corporation (GWSC), a public utility service, which was set up in 1965 has at present a semi-autonomous or autonomous section known as the Community Water and Sanitation Division (CWSD) which is responsible for rural water supply and sanitation.

Until recently, the GWSC did not have a specialised division that dealt with groundwater resources, hence some individuals, agencies and NGOs planned, implemented and operated their own schemes which did not, at all times, meet the criteria set by GWSC. Whilst some of these schemes have sometimes disregarded priorities in the implementation of National Water Supply Programme, others have supplemented Government efforts in areas of great need. These days there is a better co-ordination between the NGOs and the other interested parties on one hand and the CWSD of GWSC on the other hand.

Previously there was no proper "hand over" of drilling projects to the rural communities as the locals were not trained sufficiently to take over the running of the systems. To arrest such a situation, there is now what is known as the "community participation" which among others include the rural beneficiaries in the planning, implementation, operation and maintenance of rural water supply schemes.

Some decline in groundwater levels have been observed in certain parts of the country. This may be due to poor spacing of wells which manifest themselves in low yields, over exploitation of aquifers and low recharge resulting from the observed declining rainfall in the last decade in certain areas. This therefore calls for refinement of well field design criteria and new recommendation on pumping to arrest the overdraft.

About 40% of boreholes in the country are between 15 and 35 years old. Since they were first constructed, the wells have scarcely been maintained or rehabilitated. This has led to the disuse of some of these boreholes. The Canadian International Development Agency (CIDA) sometime ago in the late seventies and early eighties undertook some rehabilitation of some boreholes in the Upper Regions of the country. Currently, some rehabilitation works are being undertaken on some boreholes in the Northern and Upper Regions and in certain district capitals.

With the exception of the Volta Region where almost all the springs have been identified and some have been developed and are being developed [6], the national development of springs as sources for rural water supply is still rudimentary. There is a greater need to identify and document the locations of springs in the country in order to promote their large scale use. This is because springs are cheaper to develop and the technology can easily be within the reach of local rural water supply engineers.

The most prominent water quality problem with groundwater supply in Ghana is excessive iron concentrations. A few hundred wells equipped with hand pumps have been rejected by the rural population on account of the colouration effect of the water on cooking utensils and the foodstuffs which are cooked with such water. There is therefore the need to incorporate some simple iron removal plants through which iron contaminated water from the outlets of hand pumps can flow to render the water acceptable for domestic use.

It is now the official policy to provide potable and safe drinking water for all rural communities. These rural water supply schemes which are to be based mainly on groundwater resources include hand-dug wells and boreholes fitted with hand pumps. Presently the rural communities in Ghana can be categorized into two basic groups. Firstly, those that have benefited from the official rural water supply schemes and secondly those which have not. Even for those rural communities which have benefited from the official policy, there is sometimes the problem of reliability and/or adequacy of the existing systems. These latter rural communities sometimes return to their traditional sources of water supply much in the same way as those which have so far not benefited from the official policy of potable water supply. The traditional systems which are insufficient both in quantity and quality include dug-wells, ponds, dug-outs, springs, ephemeral streams and rainwater harvesting. Presently about 52% of the rural inhabitants have access to potable water mainly from groundwater sources. The groundwater resources appear to be the key to the development of the rural water supply industry and should therefore be managed and utilized on sustainable basis to meet future challenges. However, it has to be emphasized that due to geological limitations it is not everywhere that groundwater is available or available in the required quantities. Some rural communities therefore have to rely solely on surface water resources whilst others have to resort to conjunctive use of both surface and groundwater resources. To achieve 100% rural coverage by the year 2020 a huge capital outlay of about 1 billion dollars is required.

The authors are particularly grateful to the Community Water and Sanitation Division (CWSD) of the Ghana Water and Sewerage Corporation (GWSC) for providing information on boreholes and hand-dug wells. They are also grateful to the Water Resources Research Institute (CSIR) for the provision of the borehole yield and static water level maps.

REGION	ITEM	MAIN SOURCE OF WATER SUPPLY
REGION	ITEM	All sources of water supply	Pipe borne	Rain water	Borehole	Well	Dam, pond, lake	Dug-out	River, stream, canal	Spring	Not stated
ALL REGIONS	L P	56,170 12,296,081	1,501 4,496,308	46 4,443	4,309 2,028,870	6,547 1,369,905	3,239 589,900	3,688 411,021	33,951 3,217,561	352 54,459	2,537 123,613
Western	L P	8,933 1,157,807	147 375,491	1 101	348 196,582	1,066 134,661	30 5,099	400 17,343	6,486 404,837	18 4,341	437 19,352
Central	L P	6,020 1,142,335	360 532,241	4 546	355 146,800	730 129,502	193 15,229	378 31,358	3,720 275,326	48 2,818	232 8,515
Greater Accra	L P	1,171 1,431,099	248 1,274,058	0 0	83 9,135	257 65,063	141 18,299	161 21,847	262 19,894	8 911	11 1,892
Eastern	L P	5,596 1,680,890	189 535,928	7 266	355 248,232	877 224,463	337 61,622	535 80,596	3,127 509,024	22 3,862	147 16,896
Volta	L P	6,142 1,211,907	111 252,334	12 1,917	278 130,609	1,050 232,033	1,490 179,469	313 36,110	2,702 355,371	38 6,494	103 8,030
Ashanti	L P	12,053 2,090,100	229 792,490	2 36	417 381,192	740 136,332	21 6,254	451 30,489	9,317 710,597	38 6,494	383 26,216
B-Ahafo	L P	9,334 1,206,608	84 315,117	12 836	211 103,458	883 146,439	240 26,568	915 57,187	6,245 525,673	83 9,732	661 21,598
Northern	L P	3,566 1,164,583	74 249,628	6 651	93 23,203	555 207,009	675 251,775	348 100,613	1,729 318,874	23 2,800	63 10,050
U-West	L P	1,192 438,008	24 66,263	2 90	745 298,482	51 7,421	56 9,835	104 20,272	188 30,708	4 1,021	18 3,916
U-East	L P	2,163 772,744	35 102,758	0 0	1,424 491,177	338 86,982	56 15,770	83 15,206	175 47,257	25 6,446	25 7,148