Misplaced Pages

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90-628: The Waterberg Coalfield is located in the Limpopo province of South Africa, west of Lephalale . Its dimensions are about 85 kilometres (53 mi) from east to west and about 40 kilometres (25 mi) from north to south. It is part of the same formation as the Mmamabula coalfields in Botswana , to the west. It contains about 40% of South Africa's coal resources. The Waterberg Coalfield has been estimated to hold about 50 billion tons, of which about

180-408: A drop in the ground surface. In unconsolidated aquifers, groundwater is produced from pore spaces between particles of gravel, sand, and silt. If the aquifer is confined by low-permeability layers, the reduced water pressure in the sand and gravel causes slow drainage of water from the adjoining confining layers. If these confining layers are composed of compressible silt or clay, the loss of water to

270-402: A former lake bed, has experienced rates of subsidence of up to 40 centimetres (1 foot 4 inches) per year. For coastal cities, subsidence can increase the risk of other environmental issues, such as sea level rise . For example, Bangkok is expected to have 5.138 million people exposed to coastal flooding by 2070 because of these combining factors. If the surface water source

360-508: A game auction, horse jumping, dog shows, agricultural activities, a three-day 4x4 competition, a game farms expo, hunting opportunities, bird and tree identification competitions, traditional food, live music, a beer tent and huge camp fires. This river and its tributaries rise in the western part of the Waterberg (between 1200 and 1600 metres above mean sea level). It originates in a flattish, open area with numerous koppies and flows through

450-1076: A global level, although priority chemicals will vary by country. There is a lot of heterogeneity of hydrogeologic properties. For this reason, salinity of groundwater is often highly variable over space. This contributes to highly variable groundwater security risks even within a specific region. Salinity in groundwater makes the water unpalatable and unusable and often occurs in coastal areas, for example in Bangladesh and East and West Africa. Municipal and industrial water supplies are provided through large wells. Multiple wells for one water supply source are termed "wellfields", which may withdraw water from confined or unconfined aquifers. Using groundwater from deep, confined aquifers provides more protection from surface water contamination. Some wells, termed "collector wells", are specifically designed to induce infiltration of surface (usually river) water. Aquifers that provide sustainable fresh groundwater to urban areas and for agricultural irrigation are typically close to

540-408: A home and then returned to the ground in another well. During cold seasons, because it is relatively warm, the water can be used in the same way as a source of heat for heat pumps that is much more efficient than using air. Groundwater makes up about thirty percent of the world's fresh water supply, which is about 0.76% of the entire world's water, including oceans and permanent ice. About 99% of

630-730: A large community of baboon spiders existed in the area. As these long lived species, golden-brown and burst-horned baboon spiders are protected under the National Environmental Management: Biodiversity Act, 175 individuals along the Nelson Mandela Road and another 376 along the Kuipersbult Road, were captured. An 800 ha portion in the south of the Manketti Game Reserve , some 5–10 km from

720-605: A linear form along the R517 road, and also along the main road that leads to Stockpoort. The Lephalale-Stockpoort road is the main connection road between the Marapong community and Lephalale/Onverwacht. Lephalale is situated between 23°30' and 24°00' south latitude and 27°30' and 28°00' east longitude and the town is positioned west of the Mokolo river , a tributary to the Limpopo river, 820 meters above sea level. In Lephalale,

810-519: A long time without severe consequences. Nevertheless, over the long term the average rate of seepage above a groundwater source is the upper bound for average consumption of water from that source. Groundwater is naturally replenished by surface water from precipitation , streams , and rivers when this recharge reaches the water table. Groundwater can be a long-term ' reservoir ' of the natural water cycle (with residence times from days to millennia), as opposed to short-term water reservoirs like

900-718: A major economic activity, whilst cattle farming is declining to make way for game farming. Public transport in Lephalale is provided by a number of taxi operators and two bus companies, Lowveld Bus Services and Phadziri Brothers . Lowveld Bus Services provides local and long distance services between Lephalale and surrounding villages. In addition it has a contract to provide services for the transportation of labourers to Grootegeluk and Matimba. Phadziri bus service also provides some services to Eskom. The major economic activities of around town includes: The Bushveld Festival takes place in early July. The festival includes cattle shows,

990-722: A permanently reduced capacity to hold water. The city of New Orleans, Louisiana is actually below sea level today, and its subsidence is partly caused by removal of groundwater from the various aquifer/aquitard systems beneath it. In the first half of the 20th century, the San Joaquin Valley experienced significant subsidence , in some places up to 8.5 metres (28 feet) due to groundwater removal. Cities on river deltas, including Venice in Italy, and Bangkok in Thailand, have experienced surface subsidence; Mexico City, built on

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1080-728: A quarter could be extracted using opencast mining . The coal-bearing rocks are in the Grootegeluk Formation within the Karoo Supergroup . They were deposited from 260 to 190 million years ago, and are bounded by the Limpopo Mobile Belt to the north and the Eenzaamheid and Ellisras Faults to the south. The more recent Daarby Fault cuts across the coalfield. The recent covering comes from weathering of Limpopo Mobile Belt gneiss and Karoo rock in

1170-581: A relatively small part of the Waterberg coalfield is shallow enough to be accessed by open pit mining. The Eenzaamheid fault and the Daarby fault divide the Waterberg coalfield into open pit mineable and underground mineable resources. Grootegeluk is located in the narrow band between these faults. South of the Eenzaamheid fault and in between the Daarby fault and the Zoetfontien fault, in the north, coal

1260-766: A steep gorge emerging above the town of Vaalwater. Here the river flows through a relatively flat area until it enters the Mokolo Dam. From there, it flows through another gorge before entering the Limpopo Plain, near the junction with the Rietspruit. From this point, the Mokolo River flows through flat sandy areas until it reaches the Limpopo River. Fish species found in the Mokolo include: The area

1350-399: Is a highly useful and often abundant resource. Most land areas on Earth have some form of aquifer underlying them, sometimes at significant depths. In some cases, these aquifers are rapidly being depleted by the human population. Such over-use, over-abstraction or overdraft can cause major problems to human users and to the environment. The most evident problem (as far as human groundwater use

1440-528: Is also often withdrawn for agricultural , municipal , and industrial use by constructing and operating extraction wells . The study of the distribution and movement of groundwater is hydrogeology , also called groundwater hydrology . Typically, groundwater is thought of as water flowing through shallow aquifers, but, in the technical sense, it can also contain soil moisture , permafrost (frozen soil), immobile water in very low permeability bedrock , and deep geothermal or oil formation water. Groundwater

1530-466: Is also subject to substantial evaporation, a groundwater source may become saline . This situation can occur naturally under endorheic bodies of water, or artificially under irrigated farmland. In coastal areas, human use of a groundwater source may cause the direction of seepage to ocean to reverse which can also cause soil salinization . As water moves through the landscape, it collects soluble salts, mainly sodium chloride . Where such water enters

1620-632: Is an additional water source that was not used previously. First, flood mitigation schemes, intended to protect infrastructure built on floodplains, have had the unintended consequence of reducing aquifer recharge associated with natural flooding. Second, prolonged depletion of groundwater in extensive aquifers can result in land subsidence , with associated infrastructure damage – as well as, third, saline intrusion . Fourth, draining acid sulphate soils, often found in low-lying coastal plains, can result in acidification and pollution of formerly freshwater and estuarine streams. Groundwater

1710-417: Is concerned) is a lowering of the water table beyond the reach of existing wells. As a consequence, wells must be drilled deeper to reach the groundwater; in some places (e.g., California , Texas , and India ) the water table has dropped hundreds of feet because of extensive well pumping. The GRACE satellites have collected data that demonstrates 21 of Earth's 37 major aquifers are undergoing depletion. In

1800-490: Is danger of self-heating or spontaneous combustion from dumps of waste coal , releasing toxic gases. Deposition of waste products released into the atmosphere will affect the Limpopo basin ecosystem, which contains some unique species which existence is already endangered. Growth of the human population, with new housing and new agricultural operations may add more stress. Mine and power station design and operation must understand these impacts and include measures to minimize

1890-536: Is dominated by mining, electricity production, tourism, agriculture and game farming. Lephalale is rich with coal which is mined by Exxaro at the Grootegeluk coal mine . The Waterberg coalfield has an estimated resource of 75-billion tons of coal, which is 40% of South Africa's remaining coal resource. The coalfield's 75-billion tons are in 11 zones, which consist of bright coal with interbedded shale and dull coal, sandstone and carbonaceous shale. However, only

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1980-401: Is dominated by mixed bushveld and sour bushveld (sourveld). In the Limpopo Plain, arid sweet bushveld occurs while pockets of north-eastern mountain sourveld occur in higher lying areas to the south of the catchment. Situated 10 km from the town of Lephalale, this resort gets its name from the massive nyala tree that is characteristic of the area, and is also the southernmost habitat of

2070-512: Is found from 250 m below surface and deeper. The Grootegeluk coal mine is the largest open cast coal mine together with beneficiation plants of its kind in the world. It produces more than 17 million tonnes of coal product per year and the mine provides iron and ore industries with high grade metallurgical coal for iron and steel production. The low grade coal is supplied to Eskom's Matimba Power Station . Besides Exxaro , Anglo Coal , Sekoko Coal and Resgen mining houses also have operations in

2160-412: Is fresh water located in the subsurface pore space of soil and rocks . It is also water that is flowing within aquifers below the water table . Sometimes it is useful to make a distinction between groundwater that is closely associated with surface water , and deep groundwater in an aquifer (called " fossil water " if it infiltrated into the ground millennia ago ). Groundwater can be thought of in

2250-427: Is hypothesized to provide lubrication that can possibly influence the movement of faults . It is likely that much of Earth 's subsurface contains some water, which may be mixed with other fluids in some instances. Groundwater is often cheaper, more convenient and less vulnerable to pollution than surface water . Therefore, it is commonly used for public drinking water supplies. For example, groundwater provides

2340-545: Is less visible and more difficult to clean up than pollution in rivers and lakes. Groundwater pollution most often results from improper disposal of wastes on land. Major sources include industrial and household chemicals and garbage landfills , excessive fertilizers and pesticides used in agriculture, industrial waste lagoons, tailings and process wastewater from mines, industrial fracking , oil field brine pits, leaking underground oil storage tanks and pipelines, sewage sludge and septic systems . Additionally, groundwater

2430-400: Is on the northern slopes of the Waterberg mountains and has the advantage of both sweet veld as well as sour veld. Mokolo Dam into which the Mokolo River flows, is fairly large and water enthusiasts, campers, anglers and birders all regard the reserve as a sanctuary, set as it is against the beautiful mountains. Mokolo Nature Reserve is true bush, offering open savannah and more dense bushveld to

2520-468: Is rapidly increasing with population growth, while climate change is imposing additional stress on water resources and raising the probability of severe drought occurrence. The anthropogenic effects on groundwater resources are mainly due to groundwater pumping and the indirect effects of irrigation and land use changes. Groundwater plays a central role in sustaining water supplies and livelihoods in sub-Saharan Africa . In some cases, groundwater

2610-560: Is susceptible to saltwater intrusion in coastal areas and can cause land subsidence when extracted unsustainably, leading to sinking cities (like Bangkok ) and loss in elevation (such as the multiple meters lost in the Central Valley of California ). These issues are made more complicated by sea level rise and other effects of climate change , particularly those on the water cycle . Earth's axial tilt has shifted 31 inches because of human groundwater pumping. Groundwater

2700-400: Is the most accessed source of freshwater around the world, including as drinking water , irrigation , and manufacturing . Groundwater accounts for about half of the world's drinking water, 40% of its irrigation water, and a third of water for industrial purposes. Another estimate stated that globally groundwater accounts for about one third of all water withdrawals , and surface water for

2790-456: Is used for irrigation. Occasionally, sedimentary or "fossil" aquifers are used to provide irrigation and drinking water to urban areas. In Libya, for example, Muammar Gaddafi's Great Manmade River project has pumped large amounts of groundwater from aquifers beneath the Sahara to populous areas near the coast. Though this has saved Libya money over the alternative, seawater desalination,

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2880-571: Is used for the generation of steam. It happened by a decision by Eskom to build the air-cooled Matimba Power Station in close vicinity of the Iscor coal mine. Construction of the power station commenced in April 1981 and the first phase became operational shortly thereafter. Matimba was officially opened on 17 November 1989. Full municipal status was granted to Ellisras on 1 July 1986 by means of Administrator's notice 35 of 1986. The D'nyala Nature Reserve

2970-659: The African National Congress (ANC) met at D'nyala for two more bush conferences. It was after these meetings that the government and the ANC began formally working on the new constitution that would lead to South Africa's first democratic elections in April 1994. The name of Ellisras town was changed to Lephalale during 2002. The town is divided into three major extensions: The Lephalale Municipality (LM) area comprises two (2) urban nodes, namely Lephalale/Onverwacht and Marapong (Provincial Growth Point), as well as

3060-495: The Ellisras Basin in 1920, but for many years little was done to explore the resource. During and after World War II , 143 diamond-drill holes and two prospecting shafts were sunk between 1941 and 1952 to obtain a geological map of the Waterberg coalfield. Iscor bought the surface rights on six farms in 1957, and in 1973 began intensive exploration to assess the quantity and quality of coal on this property. Iscor bought

3150-577: The Glen Alpine Dam , which forms 11 km of the eastern boundary of Wonderkop Nature Reserve . It was proclaimed as a provincial nature reserve in June 1994. Environmental education is conducted in the areas adjacent to the reserve and the sustainable utilisation of natural resources is promoted from which the surrounding communities could benefit. A road upgrade project revealed in March 2012, that

3240-601: The Port of Richards Bay on the Indian Ocean . In February 2012, the state-owned rail company Transnet stated that they were adding enough capacity to be able to ship an additional 23 million tons of coal a year from the Waterberg Coalfield to Richards Bay. The new Swazilink railway would reduce load on the coal-carrying lines. Transnet was working with the mining companies to ensure that available capacity

3330-585: The Punjab region of India , for example, groundwater levels have dropped 10 meters since 1979, and the rate of depletion is accelerating. A lowered water table may, in turn, cause other problems such as groundwater-related subsidence and saltwater intrusion . Another cause for concern is that groundwater drawdown from over-allocated aquifers has the potential to cause severe damage to both terrestrial and aquatic ecosystems – in some cases very conspicuously but in others quite imperceptibly because of

3420-474: The Waterberg Coalfield . The town was established as Ellisras in 1960 and named after Patrick Ellis and Piet Erasmus who settled on a farm there in the 1930s. In 2002, Ellisras was renamed Lephalale by the provincial government of Limpopo, after the main river that crosses the municipality. Lephalale is derived from the setswana language meaning "to flow". Late Iron Age cattle posts belonging to

3510-442: The hydraulic pressure of groundwater in the pore spaces of the aquifer and the aquitard supports some of the weight of the overlying sediments. When groundwater is removed from aquifers by excessive pumping, pore pressures in the aquifer drop and compression of the aquifer may occur. This compression may be partially recoverable if pressures rebound, but much of it is not. When the aquifer gets compressed, it may cause land subsidence,

3600-405: The vadose zone below plant roots and is often expressed as a flux to the water table surface. Groundwater recharge also encompasses water moving away from the water table farther into the saturated zone. Recharge occurs both naturally (through the water cycle ) and through anthropogenic processes (i.e., "artificial groundwater recharge"), where rainwater and/or reclaimed water is routed to

3690-565: The Hans Strijdom Dam) was constructed in 1979-1980 on the Mokolo River, near Lephalale. The Malmanie River and the Bulspruit River, two tributaries of the Mokolo, also enter the dam from its left side. The dam mainly serves municipal and industrial purposes. Since Iscor became part of Ellisras, Eskom also decided to extend its interest to Ellisras seeing that the steam coal produced is suitable for use in power stations and

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3780-560: The Lephahale area. Lephalale hosts two of South Africa's power stations: Agricultural and farming activities in Lephalale include: Cattle, goats and ostriches. Vegetables, cotton, tobacco, citrus, paprika, peppers, cucumbers, tomatoes, pumpkins, lucern, groundnuts, dry beans, wheat, maize, cut flowers and water melons. Lephalale is annually the first to produce water melons sold to the general market. Game (including rare species like roan, sable and buffalo) has in recent years become

3870-471: The Letsibogo ceramic facies have been found in the area. Some rock engravings at Nelsonkop have been recorded. The name Ellisras originates from a combination of the surnames of Patric Ellis and Piet Erasmus who settled in the 1930s on the farm Waterkloof 502LQ. Since the opening of the main route between Vaalwater and Stockpoort during 1929 a railway bus stop developed on the farm. The central function of

3960-584: The Waterberg and was due to open in 2012. Because of the shortage of water, the Medupi station will use air-cooled condensers. Sasol is also interested in exploiting the field with a planned new power station called Project Mafutha, which may be located in the Waterberg. A joint venture between the Australian Firestone Energy and the local Sekoko coal is also active in the region. Exxaro expects to expand exports of high-quality coal through

4050-561: The age of groundwater obtained from different parts of the Great Artesian Basin, hydrogeologists have found it increases in age across the basin. Where water recharges the aquifers along the Eastern Divide , ages are young. As groundwater flows westward across the continent, it increases in age, with the oldest groundwater occurring in the western parts. This means that in order to have travelled almost 1000 km from

4140-493: The animals that roam here. An area of the District Municipality was designated as a Waterberg Biosphere Reserve (Waterberg District Municipality, 2010). The biosphere reserve concept is aimed at achieving a balance between the pressures of the tourism industry, the need to generate direct benefits to local communities and conservation of the cultural and natural heritage assets. The Waterberg Biosphere Reserve

4230-405: The aquifer reduces the water pressure in the confining layer, causing it to compress from the weight of overlying geologic materials. In severe cases, this compression can be observed on the ground surface as subsidence . Unfortunately, much of the subsidence from groundwater extraction is permanent (elastic rebound is small). Thus, the subsidence is not only permanent, but the compressed aquifer has

4320-525: The aquifers are likely to run dry in 60 to 100 years. Groundwater provides critical freshwater supply, particularly in dry regions where surface water availability is limited. Globally, more than one-third of the water used originates from underground. In the mid-latitude arid and semi-arid regions lacking sufficient surface water supply from rivers and reservoirs, groundwater is critical for sustaining global ecology and meeting societal needs of drinking water and food production. The demand for groundwater

4410-665: The area by the plains, a few examples include tawny eagle , kori bustard , red-billed oxpecker , black stork , black-winged pratincole , white-backed vulture , Cape vulture , marabou stork , yellow-billed stork , martial eagle , secretarybird , bateleur , lappet-faced vulture , golden-breasted bunting , yellow-fronted canary , bushveld pipit , Cape longclaw , long-tailed paradise-whydah , violet-eared waxbill , African quailfinch , lesser masked-weaver , red-billed buffalo-weaver , capped wheatear , fiscal flycatcher , Chestnut-backed sparrow-lark , rufous-naped lark , arrow-marked babbler and orange-breasted bush-shrike . In

4500-469: The area. There is one National road running through the area and three main Provincial roads serve the area, namely: These roads serve as links between Thabazimbi , Vaalwater , Ellisras and Mokopane . The P84/1 and 198/1 run mostly along the drainage subsystems in the area. These main roads are tarred and are in relatively good condition. The towns developed around the central business district in

4590-598: The atmosphere and fresh surface water (which have residence times from minutes to years). Deep groundwater (which is quite distant from the surface recharge) can take a very long time to complete its natural cycle. The Great Artesian Basin in central and eastern Australia is one of the largest confined aquifer systems in the world, extending for almost 2 million km . By analysing the trace elements in water sourced from deep underground, hydrogeologists have been able to determine that water extracted from these aquifers can be more than 1 million years old. By comparing

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4680-510: The atmosphere through evapotranspiration , these salts are left behind. In irrigation districts, poor drainage of soils and surface aquifers can result in water tables' coming to the surface in low-lying areas. Major land degradation problems of soil salinity and waterlogging result, combined with increasing levels of salt in surface waters. As a consequence, major damage has occurred to local economies and environments. Aquifers in surface irrigated areas in semi-arid zones with reuse of

4770-472: The beginning of his presidency in 1989, former President F. W. de Klerk took his entire cabinet, plus a group of officials and advisors, to D'nyala for a two-day "bosberaad". This conference involved discussions about policy development and strategies for change within the old South Africa. On 2 February 1990, a mere two months after this first bush conference, De Klerk announced the coming release of hundreds of political prisoners, including Nelson Mandela , and

4860-494: The capture site, was identified as a suitable new habitat. Artificial burrows were created and the spiders were relocated. This project is considered unique as the large scale relocation of invertebrates is a rare occurrence. Groundwater This is an accepted version of this page Groundwater is the water present beneath Earth 's surface in rock and soil pore spaces and in the fractures of rock formations . About 30 percent of all readily available fresh water in

4950-616: The centre of D'nyala, is a VIP mansion, and a conference centre that is of historical significance. Adjacent to the Mokolo Nature Reserve of 4,600 hectares is the Mokolo dam, the biggest dam in the Limpopo Province and bordering for 6 km on the Mokolo river, flows out of this dam. Approximately 50 km to the south of Lephalale, this dam is well suited for water sports enthusiasts, campers and day visitors. The dammed up Mokolo river winds around mountains. It

5040-485: The country's largest steel producer, and also the biggest consumer of coking coal, actively participated in this programme. Drilling was completed in 1952. In 1957, Iscor obtained the surface rights to six farms, including Grootegeluk. The first townships that were proclaimed in Ellisras were: Ellisras (Proper) - 7 December 1960 Ellisras Extension 1–5 May 1965 Ellisras Extension 2–3 November 1971 A major influence on

5130-491: The current population growth rate. Global groundwater depletion has been calculated to be between 100 and 300 km per year. This depletion is mainly caused by "expansion of irrigated agriculture in drylands ". The Asia-Pacific region is the largest groundwater abstractor in the world, containing seven out of the ten countries that extract most groundwater (Bangladesh, China, India, Indonesia, Iran, Pakistan and Turkey). These countries alone account for roughly 60% of

5220-404: The extended period over which the damage occurs. The importance of groundwater to ecosystems is often overlooked, even by freshwater biologists and ecologists. Groundwaters sustain rivers, wetlands , and lakes , as well as subterranean ecosystems within karst or alluvial aquifers. Not all ecosystems need groundwater, of course. Some terrestrial ecosystems – for example, those of

5310-407: The extent, depth and thickness of water-bearing sediments and rocks. Before an investment is made in production wells, test wells may be drilled to measure the depths at which water is encountered and collect samples of soils, rock and water for laboratory analyses. Pumping tests can be performed in test wells to determine flow characteristics of the aquifer. The characteristics of aquifers vary with

5400-422: The famous baobab tree. D'nyala boasts a diversity of game which includes some 65 mammal species such as nyala, white rhinoceros, giraffe, waterbuck, tsessebe, oryx, eland, zebra, impala, caracal, African wildcat, brown hyena, black-backed jackal and leopard. The animals of D'nyala roam freely over the area including the vicinity of the chalets. 263 bird species have been identified including waterfowl attracted to

5490-472: The geology and structure of the substrate and topography in which they occur. In general, the more productive aquifers occur in sedimentary geologic formations. By comparison, weathered and fractured crystalline rocks yield smaller quantities of groundwater in many environments. Unconsolidated to poorly cemented alluvial materials that have accumulated as valley -filling sediments in major river valleys and geologically subsiding structural basins are included among

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5580-404: The globe includes canals redirecting surface water, groundwater pumping, and diverting water from dams. Aquifers are critically important in agriculture. Deep aquifers in arid areas have long been water sources for irrigation. A majority of extracted groundwater, 70%, is used for agricultural purposes. In India, 65% of the irrigation is from groundwater and about 90% of extracted groundwater

5670-416: The ground surface (within a couple of hundred metres) and have some recharge by fresh water. This recharge is typically from rivers or meteoric water (precipitation) that percolates into the aquifer through overlying unsaturated materials. In general, the irrigation of 20% of farming land (with various types of water sources) accounts for the production of 40% of food production. Irrigation techniques across

5760-563: The growth of the farm Waterkloof 502LQ was the decision of Iscor in 1973 to continue with the development of the Grootegeluk Coal Mine . Work commenced in December 1974 on building the mine and one year later in December 1975, the actual quarrying of the mine commenced. Grootegeluk mine was officially opened on 15 April 1981. On 3 March 1982 this mine was in full operation for the first time. Mokolo Dam (previously known as

5850-476: The impact. On the other hand, many of the local people are unskilled and unemployed. Development of the coalfields and related chemical industries, with improvements to infrastructure, education and health services could provide large benefits if managed correctly. Lephalale Lephalale , formerly known as Ellisras , is a coal mining town in the Limpopo province of South Africa immediately east of

5940-699: The largest source of usable water storage in the United States , and California annually withdraws the largest amount of groundwater of all the states. Underground reservoirs contain far more water than the capacity of all surface reservoirs and lakes in the US, including the Great Lakes . Many municipal water supplies are derived solely from groundwater. Over 2 billion people rely on it as their primary water source worldwide. Human use of groundwater causes environmental problems. For example, polluted groundwater

6030-503: The legalization of black liberation organizations that had been outlawed for 30 years. He also proclaimed his then government's willingness to end apartheid and to negotiate a new constitution to the benefit of all South Africans. Over the next four years De Klerk returned to the D'nyala seven more times with various officials in order to work out solutions for crises that arose during the negotiation processes. In December 1992 and January 1993, for example, government officials and members of

6120-518: The local hydrogeology , may draw in non-potable water or saltwater intrusion from hydraulically connected aquifers or surface water bodies. This can be a serious problem, especially in coastal areas and other areas where aquifer pumping is excessive. Subsidence occurs when too much water is pumped out from underground, deflating the space below the above-surface, and thus causing the ground to collapse. The result can look like craters on plots of land. This occurs because, in its natural equilibrium state,

6210-464: The mines and the power stations. However, the reserve is very large and could potentially be mined for the next 200 years. It seems plausible that industry will move to the region, infrastructure will be developed and ways will be found to bring water from other regions. The Waterberg Coalfield may well replace the Mpumalanga coalfields, which are now reaching peak production. Coal was found in

6300-461: The mining lease on the farms in 1979 and established the Grootegeluk Coal Mine in 1980. In 2005 this open-pit colliery was the only coal operation in the coalfield. As of 2008, Exxaro Resources was operating the Grootegeluk coal mine, supplying Eskom 's coal-fired Matimba Power Station . In 2007 Exxaro had obtained a contract to supply Eskom's new Medupi Power Station , which is also in

6390-412: The most productive sources of groundwater. Fluid flows can be altered in different lithological settings by brittle deformation of rocks in fault zones ; the mechanisms by which this occurs are the subject of fault zone hydrogeology . Reliance on groundwater will only increase, mainly due to growing water demand by all sectors combined with increasing variation in rainfall patterns . Groundwater

6480-536: The newly established nodes became more evident and other facilities such as schools, churches and shops were established on the farm. Subdivision of the farm started and due to the specific locality of the river, all newly created portions have a river frontage which had a definite influence on the urban form/shape of Ellisras today. In 1941, the Geological Survey Division of the then Department of Mining, launched an exploration programme. Iscor ,

6570-413: The north, and from weathering of the Waterberg sandstones in the south. Thin layers of coal alternate with layers of mudstones in the Grootegeluk Formation, which is around 70 metres (230 ft) thick. Although some of the resources are near the surface and readily accessible, it may not be economically viable to extract coals from the seams that lie at depths of up to 400 metres (1,300 ft). Due to

6660-671: The open deserts and similar arid environments – exist on irregular rainfall and the moisture it delivers to the soil, supplemented by moisture in the air. While there are other terrestrial ecosystems in more hospitable environments where groundwater plays no central role, groundwater is in fact fundamental to many of the world's major ecosystems. Water flows between groundwaters and surface waters. Most rivers, lakes, and wetlands are fed by, and (at other places or times) feed groundwater, to varying degrees. Groundwater feeds soil moisture through percolation, and many terrestrial vegetation communities depend directly on either groundwater or

6750-470: The other two thirds. Groundwater provides drinking water to at least 50% of the global population. About 2.5 billion people depend solely on groundwater resources to satisfy their basic daily water needs. A similar estimate was published in 2021 which stated that "groundwater is estimated to supply between a quarter and a third of the world's annual freshwater withdrawals to meet agricultural, industrial and domestic demands." Global freshwater withdrawal

6840-683: The percolated soil moisture above the aquifer for at least part of each year. Hyporheic zones (the mixing zone of streamwater and groundwater) and riparian zones are examples of ecotones largely or totally dependent on groundwater. A 2021 study found that of ~39 million investigated groundwater wells 6-20% are at high risk of running dry if local groundwater levels decline by a few meters, or – as with many areas and possibly more than half of major aquifers  – continue to decline. Fresh-water aquifers, especially those with limited recharge by snow or rain, also known as meteoric water , can be over-exploited and depending on

6930-423: The same terms as surface water : inputs, outputs and storage. The natural input to groundwater is seepage from surface water. The natural outputs from groundwater are springs and seepage to the oceans. Due to its slow rate of turnover, groundwater storage is generally much larger (in volume) compared to inputs than it is for surface water. This difference makes it easy for humans to use groundwater unsustainably for

7020-416: The source of recharge in 1 million years, the groundwater flowing through the Great Artesian Basin travels at an average rate of about 1 metre per year. Groundwater recharge or deep drainage or deep percolation is a hydrologic process, where water moves downward from surface water to groundwater. Recharge is the primary method through which water enters an aquifer . This process usually occurs in

7110-497: The subsurface. The high specific heat capacity of water and the insulating effect of soil and rock can mitigate the effects of climate and maintain groundwater at a relatively steady temperature . In some places where groundwater temperatures are maintained by this effect at about 10 °C (50 °F), groundwater can be used for controlling the temperature inside structures at the surface. For example, during hot weather relatively cool groundwater can be pumped through radiators in

7200-445: The summers are long, hot, and partly cloudy and the winters are short, cool, dry, and clear. Over the course of the year, the temperature typically varies from 7 °C to 32 °C and is rarely below 4 °C or above 36 °C. Based on the beach/pool score, the best times of year to visit Lephalale for hot-weather activities are from early February to mid April and from early September to early November. The economy of Lephalale

7290-490: The surrounding Witpoortjie/Thabo Mbeki rural area (Provincial Growth Point), that accommodates both commercial and communal mixed-farming practices. An industrial area is also slowly developing near Onverwacht, while a heavy industrial zone has been earmarked near the Steenbokpan turnoff. The locality of the municipal area in relation to the rest of the country ensures that a number of important regional routes transverse

7380-508: The thickness of the deposits, providing roof support and preventing spontaneous combustion would be insurmountable problems. A large part of the resource is low grade bituminous, suitable for local power generation but not for export. Other drawbacks to the Waterberg Coalfield include its distance from industrial centers in South Africa, lack of infrastructure in the area and lack of water supplies. Large amounts of water are needed for both

7470-408: The unavoidable irrigation water losses percolating down into the underground by supplemental irrigation from wells run the risk of salination . Surface irrigation water normally contains salts in the order of 0.5 g/L or more and the annual irrigation requirement is in the order of 10,000 m /ha or more so the annual import of salt is in the order of 5,000 kg/ha or more. Under

7560-441: The world is groundwater. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock become completely saturated with water is called the water table . Groundwater is recharged from the surface; it may discharge from the surface naturally at springs and seeps , and can form oases or wetlands . Groundwater

7650-519: The world's liquid fresh water is groundwater. Global groundwater storage is roughly equal to the total amount of freshwater stored in the snow and ice pack, including the north and south poles. This makes it an important resource that can act as a natural storage that can buffer against shortages of surface water , as in during times of drought . The volume of groundwater in an aquifer can be estimated by measuring water levels in local wells and by examining geologic records from well-drilling to determine

7740-420: The world's total groundwater withdrawal. Groundwater may or may not be a safe water source. In fact, there is considerable uncertainty with groundwater in different hydrogeologic contexts: the widespread presence of contaminants such as arsenic , fluoride and salinity can reduce the suitability of groundwater as a drinking water source. Arsenic and fluoride have been considered as priority contaminants at

7830-406: Was being used, and that there was sufficient capacity. This could include long-term contracts to reduce risk on either side. The Waterberg area has huge areas of natural bush, and many game farms . Ecotourism and agriculture are important economic activities. There are very limited resources of groundwater . Other coal mining operations have polluted aquifers , and this must be avoided. There

7920-547: Was declared a National Priority Area in terms of Section 18(1) of the National Environmental Management: Air Quality Act, 2004 (Act No. 39 of 2004). The area requires specific air quality management actions to address the negative impacts of the air quality as a proactive approach to support future sustainable development in the area (Waterberg District Municipality, 2010). This reserve covers ±16,100 hectares and also adjoins

8010-402: Was probably around 600 km per year in 1900 and increased to 3,880 km per year in 2017. The rate of increase was especially high (around 3% per year) during the period 1950–1980, partly due to a higher population growth rate, and partly to rapidly increasing groundwater development, particularly for irrigation. The rate of increase is (as per 2022) approximately 1% per year, in tune with

8100-418: Was the site for peace talks between Nobel Peace Prize winner F. W. de Klerk and Cyril Ramaphosa before the democratic transformation in South Africa. D'nyala is referred to as the original "bosberaad" (or bush conference) centre, based on the fact that it was used for hosting high level cabinet meetings of the former apartheid -government of South Africa prior to the first democratic elections of 1994 . At

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