3.4. Study area
3.4.3. The St Lucia Estuary Mouth
3.4.3.1. Factors influencing the St Lucia estuary mouth
57 Accordingly, the biological importance of the Lake, nationally and internationally, is immense. The salinity level of the lake is the main driver for change in the environment that the lake supports and thus, the Lake is affected by the amount of freshwater entering its system. As a result, extreme weather events also play an important role in the lifecycle of the system. The system is subject to a cycle of floods and droughts of varying severity, the occurrence of which have been recorded since the early 1800s (Huizinga and van Niekerk, 2004). The result of this extreme range in weather is a variance in the state of the Lake ecosystems. While the effect of floods on the system is noteworthy, the impact of drought has been the more significant, especially in the last decade (Taylor, 10/05/2004). While drought forms part of the natural lifecycle of the ecosystem and thus is a naturally occurring event, the visual and ecosystem effects are perceived negatively. Hypersaline conditions typical of a severe drought cycle result in a reduction in species numbers, visual and biophysical changes to the ecosystems and the closure of the estuary mouth, which, among other effects, prevents the movement of marine species between the Lake and the ocean (Taylor, 10/05/2004). Consequently the state of the Lake and the estuary mouth have an influence on the state of all five ecosystems encompassed in the Park. These different ecosystems, together with the estuary mouth, compose vital pieces of an ecological “jigsaw puzzle” (Taylor, 1992: 5). Through time the various agencies and institutions responsible adopted different approaches in response to the dynamism exhibited.
58 their opponents from civil society have influenced the decisions made about the management of the mouth. At times the decisions taken have been controversial. As a result, the St Lucia estuary is well-suited for a study on environmental decision- making and politics. The interactions between the dominant role-players involved in decision-making and those in opposition are very evident throughout the recorded history of involvement with the estuary. In order to understand the technical and scientific issues that form the substantive basis of the debates, this section provides background on the St Lucia mouth. In addition, the rise of sugar farming in the region, and the change in management of the mouth over time, is described. These factors have had a strong influence in the shaping of estuary mouth events since the early 1900s.
The estuary mouth performs an important role in the functioning of the St Lucia lake system (Taylor, 1992). Figure 3.2 shows the lake tapering as it heads southwards, winding towards the Indian Ocean. This channel that connects the lake to the estuary is referred to as the Narrows. Beyond this, moving past the ‘island’ town of St Lucia towards the sea is Honeymoon Bend – an easterly turn in the course of the estuary as it makes its way towards the Indian Ocean. The area between this point and the point at which the estuary meets the sea is referred to as “the estuary mouth”. Just south of the mouth of the estuary, the mouth of the Umfolozi River is seen entering the sea.
Countless natural and human-induced openings and closures of the mouth, recorded since the early 1800s, have resulted in the estuary mouth having a dynamic history.
Table 3.1 shows a summary of these events. As shown, the closure of the mouth was a natural occurrence that formed part of the normal cycle of the system which responded to the successive phases of drought and flood accordingly. This natural process of opening and closing remained in place until 1932, when the first artificial breaching of the mouth occurred. Thus the last natural opening of the mouth was in 1923. This can be attributed to the modification of the Umfolozi floodplains during the 1920s, indicated on the table as the “drainage and canalisation of the Mfolosi swamps” in 1927. This followed the settlement of the Umfolozi valley.
59 Table 3.1: Recent history of St Lucia Estuary mouth events, up until 1970 (Huizinga and van Niekerk, 2004)
Year State
1823 Closed
1833 Closed
1849 Open
1851 Closed
1852 Open
1853 Open
1856 Open (after floods)
1885 Closed (Sept – Nov)
1895 Closed (Sept – Nov)
1902 Closed (mouth could not be crossed)
1903 Closed
1905 Open
1911 Mfolosi flood
1918 Mfolosi flood
1922 Closed
1923 Open (last natural breaching)
1925 Mfolosi flood
1927 Drainage & canalisation of Mfolosi swamps 1932 Closed, re-opened (first artificial breaching) 1951 - 1955 Closed
1955 Flood
1956 Serious flood
1955 - 1961 Closed, re-opened artificially 3 times
1963 Serious flood
1965 Closed for a few days, dredged open
60 Zululand was opened up for settlement through the Zululand Delimitation Commission undertaken from 1902 to 1904 (MacKinnon, 1990). The report released by the commission in 1904 specified the areas allocated for European occupation in Zululand (Figure 3.3). Prior to this Zululand was largely uninhabited by Europeans, except for the British and Natalian officials posted there for administration purposes.
The region was viewed by settler Europeans mainly as a game hunting ground. The settlement of Europeans in Zululand opened up the region for commercial cultivation.
Figure 3.3: Delimitation of European Settlement, including extent of Tsetse Fly (Source: MacKinnon, 1990)
61 Sugar had been established as the best crop to grow on the Natal coast by farmers further south, following unsuccessful experimentation with other crops prior to 1900 (Anon, 1965). In order to make sugar farming profitable in the Zululand region, prospective millers were offered concessions in order to start up mills and then small- scale growing was encouraged by settlers. Umfolozi Co-operative Sugar Planters (UCOSP) was founded in 1923 by sugar farmers in the area, with George Heaton- Nicholls as the first chairperson (Anon, 1965). Following numerous floods, the decision was made in the late 1920s to canalise the Umfolozi River in order to protect the farms (Wiseman, 1992). This involved dredging, widening and straightening the Umfolozi on its course to the St Lucia estuary (Anon, 1965). Soldiers returning from service during World War II in 1945 were given land in the Umfolozi valley. The result of ensuing negotiation between the Lands Department and UCOSP was the opening up of the lower Umfolozi valley for cultivation, extending the sugar farming area and increasing the production potential of the existing mill (Anon, 1965). The increase in production enabled the construction of a sugar refinery in the 1950s in Mtubatuba (Wiseman, 1992).
The 1950s were also a significant time for the St Lucia estuary. While the estuary has experienced numerous human interventions in its natural functioning since the early 1900s, perhaps the most significant was the diversion of the Umfolozi River into the Indian Ocean in 1952. Up until 1952 the Umfolozi River entered the St Lucia estuary.. Due to the canalisation of the Umfolozi by the sugar farmers in the 1920s, silt was being washed down the canal into the estuary, causing the estuary to silt up and the estuary mouth to close. A permanently open mouth was seen as the vital to the healthy functioning of the estuary and lake and thus UCOSP proposed the diversion of the Umfolozi River into the sea. This was put forward to the provincial authorities.
Following recommendations provided by organisations such as the National Resources Development Council, it was agreed that a new mouth for the Umfolozi River should be created (Anon, 1951). UCOSP undertook this procedure (Anon, 1965). This was done by blocking the path of the Umfolozi into the estuary and digging a new path through to the Indian Ocean (shown in Plates a) and b) in Appendix B).
62 At present the estuary and estuary mouth are under the jurisdiction, nationally, of the Department of Environmental Affairs and Tourism (DEAT) through the GSLWPA, as well as the Department of Water Affairs and Forestry. Provincial government involvement is headed by Ezemvelo KZN Wildlife under the Department of Agriculture and Environmental Affairs. EKZN Wildlife holds a management agreement with the GSLWPA, in which they provide the daily conservation services needed to run the Park, which includes the physical management of the mouth.
3.4.3.2. Management of the St Lucia estuary mouth