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Table K4 provides monthly discharge data for nine unprotected springs in the peri­
urban/rural Vulindlela District of KwaZulu (Alcock and Lea, 1986 - below). Discharge of
the springs reached a maximum in December or January, with a relatively steady decline
thereafter at springs 6 and 8, for example. By contrast, somewhat rapid reductions in the
discharge were observed at springs 1 and 9, with springs 2, 3 and 4 exhibiting a semi­
uniform discharge pattern. Minimum discharge periods for all springs varied from March
to September. The discharge pattern suggests that springs 2, 3 and 4 could be artesian
in origin, in view of the generally high and sustained discharge throughout the survey
period. Spring 9 can be classified as a gravity depression spring subject to a small and
highly variable yield. The other springs are probably of the gravity overflow category, in
terms of a less variable and higher discharge by comparison with gravity depression
springs.
Springs in the study area are frequently found along the midslopes at nick-points (sudden
changes in slope), often accompanied by a change in soil texture, with the more
impervious clay having been deposited where the slope is flatter. Springs are also evident
in minor hillslope valleys as well as at geological interfaces and outcrops, or along the
footslopes of valley bottoms, and at the mouth of intersecting valleys. Multiple spring
lines stacked vertically above each other are common where dolerite sills have intruded at
several horizons in the stratigraphy. Relatively few springs are located near or on top of
the crests of hills. Intrusive Karoo dolerite in the form of vertical or near vertical dykes and
horizontal sills is found in large parts of the study area, with Ecca Group shale as well as
sandstone also widespread. The intrusion of the dolerite has a marked effect on spring
distribution, with an average of 18,5 springs km,2 observed in the study area. By
contrast, the spring density in another part of KwaZulu (the Ximba Ward) which is
underlain by deep granite of the Basement Complex, is 0,36 springs km- 2 (Alcock, 1989 ­
above).