Description of the Edenvale Stream *
The Edenvale Stream (also called Eastleigh Stream or Eastleighspruit) begins in Klopper Park, with smaller branches from Hurlyvale and Buurendal joining at Horwood’s Farm. It flows through the center of Edenvale to meet the Jukskei River near Sizwe Hospital. There are two key issues concerning the Edenvale Stream:
- Pollution, of which sewage is the most frequent
- Risk of flooding
Development, Rainfall and flooding *
During the 1990’s and 2000’s the Meadowdale and Tunny industrial areas were developed on a large scale. About a third of the catchment area was developed in this period. This caused increased run off and regular floods the suburbs immediately downstream, Harmelia, Buurendal and Eastleigh, starting 1998. The map below shows the catchment of the Edenvale Stream. A detailed account of the floods and their causes is given in the post “Buurendal floods and Meadowdale development” and “JP Bezuidenhout Park Horwood’s Farm flood lines”
In response to the flooding the local authority built the Buurendal retention dam. The Edendale Road Bridge was upgraded and a larger concrete canal built to cope with “bigger floods”. This was completed in 2005, with the view expressed in the press that “flooding … will be a thing of the past”.
However when the next wet phase came a further ten years of development had taken place contributing additional run off. On 3 February 2009 suburbs including Buurendal, Harmelia, Eastleigh and the Avenues were flooded. The rainfall measured that day was 65 mm, which is not exceptional. The following year there were more floods. The number of articles in the Bedfordview Edenvale News per year about of floods tells the story: there was only one article in the period 1998 – 2000, but between 2009 and 2011 there were 19. Since the flood of November 2016 54 articles appeared.
After the 2009 flood the Buurendal retention dam was upgraded and outlet pipe enlarged to allow the dam to empty quicker. Berms were built on the south side of the R24 in Klopper Park and the channel through Harmelia was enlarged. Work on the channel of the stream continues, such as bank reinforcement and improved flow at the Plantation Road Bridge.
The impact of the increasing run off can be seen in the lower regions around the Avenues. The view upstream from the First Avenue Bridge in the next three photos shows the changes. In 2003 there was no erosion. Note the tree in the center which gives a reference point. Erosion started and in 2007 accelerated. Late that year the channel moved north of the tree and infrastructure was threatened. By 2009 the erosion was severe and manhole and pipelines had collapsed into the stream. The flood of November 2016 enlarged the channel further removed the tree.
The Eastleigh Low-lying Bridges Project is the upgrading and reconstruction of three low lying bridges over the Edenvale Stream at First Avenue, Fourth Avenue and Sixth Avenues. The bridges at Fourth and Sixth Avenues were damaged in 2009, and that at First Avenue is not large enough for future peak flows. This project requires a basic environmental assessment. The draft Basic Assessment Report (GDARD: 002/13-14/E0307) was distributed to Interested and Affected Parties on 27 June 2014 by Magalela and Associates, the Environmental Consultants, but some specialist studies were not yet done. Edenvale RiverWatch comment on the report by Irwin Juckes on 31 July 2014 identified the calculated peak flows and flood lines as greatly underestimated.
Since July 2014 this project seemed to be abandoned. In November 2016 we have floods again and the First Ave Bridge was also damaged and closed. Controversy over the state of this bridge and its reconstruction has filled the pages of the Bedfordview Edenvale News from the time of the flood to early August 2017 when it was reopened with temporary repairs.
Water quality and sewage contamination *
Edenvale RiverWatch volunteers monitor pollution in the Hurleyvale Stream (St Andrews Rd site) and Harmelia Stream (Beverley Rd site in Highway Gardens) almost daily. The Harmelia Stream has frequent periods of pollution from Klopper Park, from both sewage and industrial sources. Even when this is cleared, the Harmelia Stream remains more polluted than the Hurlyvale Stream. The chart shows a steep increase in pollution starting April 2018. The longer term graph by month shows there was a slight improvement over the last two years, but the recent spill lasting two months from April to July 2018 was the worst incident yet. Even though it appears to have stopped the state of the channel downstream is polluted beyond imagining, as shown in the video.
River health bio-monitoring *
Bio-monitoring is done by sampling the invertebrates present. The First Avenue Bridge has been monitored since 2005, and the two tributaries Harmelia Stream and Hurlyvale Stream since 2013. The results show river health always in the “Poor” category which is the lowest level, and the health of the Harmelia Stream coming from Klopper Park is the lowest.
Counts for fecal coliforms in Edenvale Stream at First Avenue, extracted from Ekurhuleni Water Quality Reports, show high levels of sewage contamination. Note this graph is plotted on a log scale.
Photo monitoring Edenvale Stream *
Edenvale RiverWatch monitors the Edenvale Stream in the lower section and upper sections of the stream. The middle section flows through a canal and is not recorded. The sites are all selected to record potential changes to the channel of the stream, the surrounding landscape or the impact of future construction work. Below is the example of the fixed point on the First Avenue Bridge looking upstream for the period 2014 – 2015.