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Table J2: Water budgets for Natal/KwaZulu and South Africa.
8
Component of the NatallKwaZulu South Africa
water budget
water percentage water percentage
(10 6 m 3 ) (10 6 m 3 )
Direct surface runoff 10508
.
13,3 36502 6,1
Groundwater recharge 2512 3,2 16893 2,8
Plant interception 14409 18,3 70100 11,6
Evapotranspiration 51 397 65,2 479011 79,5
Rainfall 78826 100 602506 100
Source: (i) After Schulze, R.E., 1979. Hydrology and water resources of the
Drakensberg, Natal Town and Regional Planning Commission Report.
VOl 42, Pietermaritzburg, 179 p.
(H) After Whitmore, J.S., 1970. The hydrology of Natal, Paper No. 1,
2nd Technical Session, Symposium Water Natal 1970, 27 - 29 May
1970, Durban, 9 p. + app.
(iii) After Whitmore, J.S., 1971. South Africa's water budget, South
African Journal of Science. VOl 67(3), p. 166 - 176.
10.3 Rivers of NatallKwaZulu
The most important rivers in NatallKwaZulu from south to north are the Mzimvubu (with
reference to East Griqualand); the Mtamvuna; the Mzimkulu; the Mkomaas; the 1II0vo; the
Mlazi; the Mgeni (main tributary the Msunduze); the Mdloti; the Mvoti; the Tugela (main
tributaries the Mooi, the Bushmans, the Bloukrans, the Little Tugela, the Upper Tugela, the
Klip, the Sundays, the Buffalo and the Blood); the Mhlatuze; the Mfolozi (tributaries the
White Mfolozi and the Black Mfolozi); the Mkuze and finally, the Pongola-Usuthu River in
the far north. It should be noted that four of South Africa's 10 largest rivers (in terms of
mean annual runoff) namely, the Tugela, the Mzimvubu, the Mkomaas and the Mzimkulu
(by comparison with other major rivers such as the Orange, the Vaal and the Limpopo),
yield between 10 - 20 times more runoff per km 2 of catchment area (Perkins, 1986)*.
*
See Perkins, J.C.. 1986. The challenge of steep land in Natal and KwaZulu: water conservation and
water development, In: Symposium on the Challenge of Steep Land in Natal and KwaZulu. Natal
Branch of the South African Society for Agricultural Extension, 16 September 1986, Cedara, 4 p.