Sustainability Indicators for Swaziland

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NATURAL RESOURCE ASPECTS OF SUSTAINABLE DEVELOPMENT IN SWAZILAND

FRESHWATER

Background

Swaziland is a well-watered country traversed by five major rivers. The combined natural discharge of all rivers leaving the country is about 4,500Mm³/yr. Current consumptive water usage is about 30 percent of that leaving the country.

A review of the limited number of available inorganic water quality analyses shows that total dissolved solids (TDS) in major rivers is generally less than 150mg/l and even lower (30mg/l) in streams on the Highveld. Nonetheless, surface waters are generally not safe for human consumption due to potential high coliform counts and the presence of bilharzia blood fluke.

Water is now one of the major constraints to development. Over the last three decades, the government has emphasised the delivery of other services such as clinics and hospitals and roads. Water resources are diminishing - but still there is no overall policy to develop water use.

It is generally believed that water resource availability in Swaziland is diminishing due to changes in the physical environment and through river control systems in neighbouring countries (principally South Africa where headwaters of three of the five large rivers lie). However no substantive studies have been undertaken over the last two decades to investigate and assess the impacts and to plan mitigative measures.

There is need to reopen discussions with the South African Government (through the Joint Water Commission Treaty of 1992). In particular political studies are needed to reopen debate on uses of water and there needs to be equitability of use.

In order for Swaziland to be effective in negotiations with neighbouring countries regarding international rivers, a National Water Master Plan should be prepared. Apart from the recent development proposals for the Komati basin with the proposed construction of the Maguga Dam, the other river basins now require updated information.

The National Water Master Plan would not only address international water rights issues, but would also serve to coordinate common policies, strategies and integrated development with regard to maximising use of water resources nationally. In addition it should investigate in detail future water resources development for irrigated agriculture, the largest consumer of water in the country and the key to the economic and financial feasibility of water resources development.

The first priority would be to develop the Usuthu Basin which potentially has five or six major dam sites for hydroelectric and agricultural uses.

In 2001 a draft National Water policy was produced to guide all water resource development. In the same year a draft Water Bill was presented to Parliament.

Water Resource Availability

A common claim is that water resource availability to Swaziland is diminishing, whether it be due to changes in the physical environment and/or through river control systems in neighbouring countries. However, no substantiative studies appear to have been undertaken over the last 15-25 years to investigate, assess the impacts and plan mitigative measures.

The last national study to be done was the "Water and Related Land Resources Framework Plan" prepared by Omaha District Corps of Engineers Department of the Army in April 1981. The purpose of the plan was to provide a conceptual framework for future water resources development decisions in Swaziland in order to enable the GOS to effectively negotiate with neighbouring countries over the international rivers.

The plan, of necessity, is very limited in depth and detail of the evaluations of specific projects as it covered the entire country and parts of other countries, and had a short time for completion. Major previous studies were therefore used in its preparation, notably the "General Plan for Development and Utilisation of Water Resources", 1970 and "Possible Future Developments in the Republic of South Africa of the Rivers of Common Interest With the Kingdom of Swaziland", 1980.

The general findings of the "Water and Related Land Resources Framework Plan" were:

Irrigated agriculture is the key consideration in future water resources development. It is by far the largest consumer of water and is the key to the economic and financial feasibility of water resources development.
Evaluations of current and proposed developments in South Africa indicate that irrigation could significantly increase abstractions from current reservoirs and these abstractions could be further increased with the addition of new reservoirs. Depending upon the basin, these actions by South Africa could create significant impacts on current and potential water resources development in Swaziland.

Potential Projects

The 1987 report also identified a number of economically feasible irrigation projects that could be developed. Obviously the justification for such projects would need to be reconsidered followed by detailed planning to arrive at firm conclusions regarding this potential in today's context. The table below summarizes the report's findings.

Potential Water Resource Developments by River Basin

River Basin	Potential (as identified in 1981 Framework Plan)	Constraints
Lomati	Lomati river could provide for 3,600 ha of additional irrigated land without storage reservoirs Construction of a reservoir would allow for the development and irrigation of an additional 14,200 ha.
Komati	Subsequent to the 1981 Plan: Maguga Dam to be constructed to impound water for irrigation development on the lower Komati, both in Swaziland and RSA. Dam to be 105m high impounding a reservoir with a gross volume of 332 Ml. for hydropower generation and irrigation of some 7,200 ha.	If RSA increases abstractions from its existing reservoirs on the Komati river to their full potential, Swaziland would experience severe shortages. These shortages could become even more severe without the specified releases which RSA proposes to reserve for Swaziland
Mbuluzi	Land irrigated by water from Mnjoli reservoir could be increased by up to 5,000 ha if Swaziland Irrigation Scheme return flows are maintained.	No additional storage could increase the irrigation potential. Conservation practices on existing irrigation schemes could increase irrigation potential.
Ngwavuma	Construction of a storage reservoir would provide for current shortages and water to irrigate an additional 2,400 ha. A large area of the most suitable land for irrigation is located in the Ngwavuma basin.	Current irrigation development in the Ngwavuma basin experiences frequent shortages. Irrigation of this land would require transporting water from the Usuthu river.
Great Usuthu	There is currently a surplus of water in the Usuthu basin. The remaining surplus combined with two storage reservoirs on the Little Usuthu would provide 90 percent of water required for irrigation of 18,000 ha in the Mabopheni, Big Bend North and South areas of the Lower Great Usuthu basin. A storage reservoir on the Upper Great Usuthu could provide water to complete irrigation in the Mabopheni area and to irrigate an additional 6,600 ha in the Lower Great Usuthu basin. Storage reservoirs in the Ngwempisi and Mkhondvo could provide enough additional water to irrigate 10,900 ha. This water could be diverted to the Ngwavuma to irrigate the good quality land in that basin.	Increased abstractions from existing RSA reservoirs and additional abstractions from proposed RSA reservoirs could reduce this surplus by about 50 percent

Groundwater

There is considerable potential for future exploitation of groundwater resources. The estimated total potential groundwater resource in Swaziland is equivalent to a sustained flow of about 20,000l/sec. To date only about six percent of the potential has been tapped. The Middleveld and Highveld areas have the highest potential for groundwater exploitation, but there are relatively few boreholes in the Highveld due to inaccessibility. By contrast, in the Lowveld, an area where potential recharge is lowest and the need for groundwater highest, boreholes presently utilise about 42% of the estimated potential recharge.

In general, groundwater quality meets WHO Drinking Water Standards, especially in the Highveld and Lubombo regions. In the Lowveld, where evapotranspiration rates are high, groundwater tends to become relatively salty.

In order to properly manage groundwater resources, it is essential that water-bearing zones are protected from pollution and that abstraction rates do not exceed natural rates of replenishment. As there is clearly a strong relationship between surface and groundwater flow, there is an additional need to ensure that surface water rights are not compromised by over-development of the groundwater reservoirs.

This page was last updated on 03 February 2004