Service Contract No 2007 / 147-446 Strategic ... - Swaziland

5.2.2 Expected impacts in absence of the NASExpansion of water use for irrigation is constrained by a lack of water storage infrastructure.Run-off river abstraction is reported to be fully allocated in all basins.In the absence of the NAS with its intended support for an expansion of the smallholderirrigation sector through the KDDP and LUSIP irrigation projects, water demand is likely toincrease only marginally unless the Government of Swaziland and other partners constructnew water storage infrastructure to store run-off for irrigation.There are competing demands for the limited water in Swaziland. The bulk of all naturalwater in the major rivers of the country is allocated to irrigation (96%) and as has beenreported elsewhere this water is fully allocated leaving very little available for industry ordomestic usage. Transboundary allocations to South Africa and Mozambique are currentlyupheld and regulated via transboundary agreements.The IWRM Plan has identified a need to develop new water sources to supplement thecurrent supplies available notably for domestic usage in the major towns and cities. TheIWRM Plan recommended raising the Mnjoli dam wall and spillway (which will raise the fullsupply level by 1.5 m and increase the dam capacity by 22.2 Mm 3 ) and constructing one ormore dams on the Mbuluzi River (Mbuluzi Falls - 14.2 Mm 3 /yr), and Mbuluzane River(Mkombane Dam, Mpisi Dam, Khuphuka Dam and Isilele Dam with a total live storagecapacity of the proposed dams of 482 Mm 3 /yr).5.2.2.1 Trends in water demandIn general water use information is lacking. Water allocated for irrigation is more closelymonitored due to the water abstraction permit requirement but the actual volume of waterabstracted/used is poorly monitored and any data or information that is collected is not easilyaccessible. Water use data based on the water permit allocations is available at a nationalscale from the Department of Water Affairs. No systematic process is in place to collect ormake available the water use by sector, and accurate and reliable data on water use in thedifferent basins is not available. More detailed information and data exists for the large-scaleirrigation project areas, e.g. LUSIP and KDDP.Table 10:Projected Irrigation Water Demand (Mm 3 /yr)CatchmentYear2005 2010 2015 2020 2025 2030Ngwavuma 47 48 48 48 48 48Upper Usuthu 40 41 42 43 43 43Lower Usuthu 269 338 562 562 N/A 564Mbuluzi 239 N/A 261 N/A 292 N/AKomatiLomati225 262 N/A N/A N/A N/ASource: IWRM Survey and Status Report: Swaziland, 2009.With the development of irrigation infrastructure through the KDDP and LUSIP schemes,irrigated area is expected to increase until the available water is fully allocated and exploited.Thereafter, little or no additional areas will come under irrigation.The GoS is investigating two new irrigation projects - one in the vicinity of Lavumisa andanother on the Mkhondo River. The combined area increase from the two proposals is notknown at this stage but is likely to be several thousands of hectares.RDMU (Strategic Environmental Assessment of the National Adaptation Strategy) - Page 45