Boksburg Lake and its catchment can be viewed as a complex system (Pollard & du Toit 2011) that is made up of a number of variables, feedback loops and drivers.
Systems dynamics is a method to model such a dynamically complex system. The most commonly used model is the causal loop diagram, which is particularly useful for communicating casual relationships between variables within a system (Pruyt 2013).
Figure 6.1 is a qualitative causal loop diagram of the economic, social and biophysical components and relationships of Boksburg Lake and its catchment and follows the methodology used by Pruyt (2013). It has been developed using the software package Vensim specifically designed for creating causal loop diagrams. Figure 6.2 is a conceptual heuristic of the same system.
Meadows (2008) stated that a consistent pattern over a long period of time is evidence of the possibility of a feedback loop. Consistent patterns in the Boksburg social-
ecological system are the persistent development, increasing deterioration of the biophysical environment (including Boksburg Lake) and the growing social problems.
Three main drivers can be identified from the results, namely the value attached to economic growth, the value of consumerism and political change. The high value of economic growth and progress has been a driver of the system from Boksburg’s early years. It increased in dominance after the two World Wars when industry became a new economic activity and catapulted Boksburg into becoming one of South Africa’s biggest industrial sites. Economic growth and progress have been supported by the increasing value of consumerism that is now pervasive. These two values have been important drivers for the unrestrained development that happened from the 1960s until the present, with some restraint from the late 1990s into the 2000s. This restraint has been partly due to pressure from civic groups responding to the increasing biophysical deterioration. The system diagram (figure 6.1) indicates that unrestrained development and urbanisation have played an indirect role in reducing the value of Boksburg Lake as a recreational asset. Reinforcing loops have developed that reduce the number of visitors to the lake and keep it in a degraded state.
The development of the multi million rand East Rand Mall in 1992, which prompted numerous additional type developments, quickly became the recreational centre of Boksburg and drew away many potential Boksburg Lake visitors. It also had an almost immediate effect on the CBD, which experienced a rapid decline in value and many of the shops were threatened with closure. It is important to note that Boksburg Lake is situated within the CBD, which began to cater for a poorer income group.
A key driver at the time was a change in political power. The ANC was elected as government in 1994, which was the culmination of a rapid shift in power dynamics from the early 1990s. Apartheid and its laws began to be dissolved and public spaces previously barred from large sectors of the population were made accessible. Boksburg Lake, which had been a racially contested space and open only to white sectors of the population, was now freely accessible and fences were taken down.
Vagrants and other impoverished segments of society began to visit Boksburg Lake.
This increased the occurrence of vandalism and consequently the deterioration of lake infrastructure (such as toilets, lighting, equipment), which reduced the number of lake visitors. This set up a reinforcing feedback loop, where fewer visitors increased the occurrence of vandalism, which would further reduce visitor numbers. The increase in illegal dumping and litter that became rife throughout the 1990s, contributed to deterioration of the lake grounds. Through stormwater runoff, much of the
accumulated litter within the catchment would end up at Boksburg Lake. With the change in power, political priorities shifted from, for example, maintaining recreational, open spaces such as Boksburg Lake, to poverty alleviation. Maintenance of the lake’s infrastructure and grounds decreased, which also contributed to their dilapidation. As these deteriorated, visitors who were previously attracted to the well maintained grounds and infrastructure that catered for the young and old (including a putt-putt course, lights and a mini train) stopped coming. This developed another reinforcing feedback loop; as the infrastructure and grounds deteriorated, fewer people visited the lake. This reduced the political incentive and consequently resources to maintain the infrastructure and grounds, which led to fewer visitors.
The poorer income groups, who began to populate the CBD, influenced the reputation of Boksburg Lake as a hotspot for crime. This set up another reinforcing feedback loop, where this growing reputation reduced the visitors to Boksburg Lake, which created favourable conditions for crime to occur (theft, rape and murder are reputed to have become common at Boksburg Lake).
As can be seen from figures 6.1 and 6.2 unrestrained development and urbanisation have influenced the deteriorating water quality of Boksburg Lake (it is now affected by over 300 000 tons of accumulated toxic sludge) (Gordon 2008). The proliferation of industrial development from the 1950s has added industrial effluent to the system, while the ERPM’s mine dump (Cason dump), consisting of toxic sediment, is situated only half a kilometre from the lake. Since its development in the late 19th century this mine has been a notable polluter of Boksburg Lake (see section 6.3.2). In 1999 the mine closed and consequently there were large dust storms due to the dumps no longer being wetted. Rapid urbanisation has also contributed to the flow of pollutants that ends up in Boksburg Lake. Reinforcing this is the fact that Boksburg is situated in one of South Africa’s primary watersheds characterised by many springs and wetlands.
Development has occurred on these wetlands, thus damaging ecological processes that would have functioned to use excess nutrients for growth, thereby absorbing pollutants (Davies & Day 1998). Illegal dumping and litter also negatively impact the lake’s water quality, both directly and indirectly and are partly an effect of the increasing value of consumerism coupled with and supporting unrestrained development and urbanisation. The deteriorating water quality hampered recreational activities such as swimming (no longer happening from about the 1970s), fishing and boating and consequently fewer people visited Boksburg Lake.
Figure 6.1: Causal loop diagram (Pruyt 2013) of the Boksburg Lake system indicating the economic, social and biophysical components and relationships of Boksburg Lake and its catchment. Key drivers, derived from emergent analytical statements (section 6.4) are represented in bold,
signifies a reinforcing feedback loop, + indicates an increase while – indicates a decrease.
Crime Malls built
Value of the Central Business District
Poorer income group +
-
Vandalism of lake infrastructure
+ Unrestrained
development &
urbanisation +
High value of economic growth &
progress
+
Value of consumerism +
Health of ecological processes
-
Boksburg Lake's water quality
Solid &
chemical pollution
Industries + +
Gold Mines +
+
- -
Illegal dumping
& litter +
Condition of BLs infrastructure &
grounds Political change
Municipal actions to maintain BL
- -
-
Civic action
+ -
R R
Visitors to + Boksburg Lake - -
- -- +
R
+ - -
Negative experience of BL
+
+
+ -
+
Civic groups -
Figure 6.2: A conceptual heuristic of the Boksburg Lake (BL) social-ecological system including: drivers impacting the system (high value of economic growth, increasing value of consumption and political change); sub-systems and their inter-relationships (biophysical, social and real actions) and factors (fewer people, deteriorating water quality, reduced political incentive & deteriorating infrastructure) locked in reinforcing feedback loops that reduce BL’s value. Single arrows indicate a one-directional relational causality; double lined arrows indicate the causal relationship between the 3 sub-systems and the 4 factors locked in reinforcing feedback loops; the + symbol signifies increasing impact while the – symbol signifies decreasing impact.
Fewer people use BL
Reduced political incentive to maintain the system Deteriorating
water quality
Deteriorating infrastructure
Increasing value of consumption High value of economic growth
Unrestrained development (1960s - present)
Vandalism of BL infrastructure such as aerators ERM becomes the prime
recreational & economic centre
Aerators blocked
& broken
CBD declines
BL attracts a different group of people
Crime increases (rape, murder)
Vandalism increases
Demographics change from higher to lower income households
Ecological processes degraded Increasing amount of industrial,
mine & other urban effluent ERM is built
Increase in illegal dumping & litter ERPM mine closes
down (1999)
Dust storms Solid & chemical pollution
Pressure is put on the municipality to improve conditions Aerators installed to improve
oxygen levels
Civic action increases
- +
+
Political change
Municipal priorities change
Key BL = Boksburg Lake CBD = Central business district ERM = East Rand Mall
Biophysical sub-system
Social sub-system
Real actions
+ +
Reinforcing feedback loops that reduce the value of BL
Civic action increased in response to both the deteriorating water quality and infrastructure. This response has been strongest when declining conditions are directly experienced. For example, between 2007 and 2008 there were multiple fish kills and a foul odour could sometimes be smelt kilometres away. Numerous articles were consequently written about Boksburg Lake’s declining conditions and considerable public pressure was placed on the Metro. The Metro consequently put some intervention measures in place. However, their ability to reverse the deteriorating conditions has been neutralised, partly due to the social context of the municipality.
For example, aerators were installed to ameliorate the lack of oxygen in the water, due to high amounts of anaerobic bacteria. However, these were soon dysfunctional due to damage from vandalism and blockages from the litter.
From 1903 to 2013 Boksburg Lake has changed from being one of Boksburg’s biggest assets (recreationally and socially) and is now a key part of the city’s degraded condition, both socially and ecologically. A set of reinforcing feedback loops has developed that locks Boksburg Lake into a particular state and neutralises actions for change. Analytical statement 5 explores this further.
5. From being one of Boksburg’s biggest assets (recreationally and socially)