Story of the Jukskei River *
The Jukskei River rises in Johannesburg and flows northwards, crossing into Bedfordview, Ekurhuleni, and back to Johannesburg. It joins the Crocodile River shortly before it enters Hartebeespoort Dam. The two great problems of the Jukskei River catchment are sewage pollution and flooding. The sewage problem is constant, while the flooding happens at intervals and tends to be overlooked during dryer times. The map shows the catchment with the main features and monitoring sites.
Jukskei River Pollution Profile *
The greatest problem of the Jukskei River is sewage pollution. This comes from aging infrastructure and a backlog of maintenance, and in some cases the use of superimposed sewage and stormwater systems, with interlinks for access. It is therefore common for sewage and stormwater to mingle if the interlinks fail.
City of Johannesburg reports water quality in the Jukskei River catchment quarterly including about 16 sites along the Jukskei River itself. City of Ekurhuleni does not test the Jukskei River, but tests tributaries that flow into the catchment. Edenvale RiverWatch tracks trends since 2014 from Ekurhuleni and 2015 from Johannesburg.
City of Johannesburg quarterly water quality reports show two peak inflows of sewage pollution. The first peak is at the source of the river in central Johannesburg. It comes from the hundreds of bad and hijacked buildings which have no services, so their sewage runs into the stormwater system. The second peak is from Alexandra, where decades of unplanned development has covered over access to the underground system and brought about over capacity.
In the upper Jukskei River in Johannesburg here are three test sites in the first 5 Km, while the next is 10 Km further downstream at Lyndhurst. Tracking these four sites shows extremely high sewage contamination at the uppermost site, often at the maximum of the test. The presence of E coli declines rapidly downstream, but contaminants continue or sink as sludge. But all sites remailn in the “unacceptable” range.
The physical and chemical tests show only ammonia and Chemical Oxygen Demand (COD) concentrations are unacceptable, but well over the limit. Nitrate rises to unacceptable at Lyndhurst, at least in part due to conversion of ammonia. COD or is a measure of organic material that can be broken down. All this points to sewage as the overwhelming source of pollution, and the timeline shows it getting worse over the last year.
Jukskei River Pollution Early years *
The National Microbiological Monitoring Program (NMMP), which falls under Department of Water and Sanitation, gives longer term results from 2003 to 2014. Reporting through NMMP at this site stopped in 2014, after the Bruma Lake was removed. The 11-year graph from NMMP shows faecal contamination is extremely high, over 1 million counts per 100 m/L. Note that this is a log plot and visually rather flattened, so it is not easy to recognize a jump of about 100-fold in 2008.
A more detailed analysis of the Jukskei River pollution profile is given here:
while detail of the serious Bruma sewage spill of April 2017 is given in these two posts
River health *
Monitoring river health by Edenvale RiverWatch shows the health of the river is lowest downstream of Johannesburg CBD and Alexandra but improves further on. While the river health improves, it does not rise above “Very Poor” ecological category which is the lowest level. River health at all sites deteriorated from 2016 to 2017 except Kyalami, but Kyalami is on a longer term deterioration (see below).
Jukskei River Health shows a steady deterioration over two years at Kyalami. This graph shows two measures of invertebrate’s presence. The horizontal axis SASS shows how much invertebrate life there is, and the vertical axis Aver Score per Taxon shows it’s quality. The box lines drawn are the boundary between Ecological Categories D (Poor) and E/F Serious/Critical. The health of the river has moved from Category D to Category E/F.
Jukskei River Catchment run-off and flooding *
Johannesburg and the rest of the Witwatersrand conurbation sits over the continental divide. The Jukskei River in the north flows toward the Limpopo River and to the Indian Ocean. The Vaal River in the south flows to the Atlantic Ocean. The city receives its water from the Vaal catchment, but the waste water flows northwards into the Jukskei catchment. Development, poor stormwater infrastructure and maintenance backlog cause increased run-off and flooding. This applies to both Johannesburg and Ekurhuleni.
Read further on how our variable climate, rainfall cycles and the impact of development increase risk of flooding here: Rainfall and Jukskei River Catchment Information.
The problem of poor development planning is shown in the post Buurendal Floods and the Meadowdale Development,
The Linksfield Mixed-Use Development is a proposed development of the area surrounding Sizwe Tropical Diseases Hospital. As presented, this development will add to Jukskei River risk of pollution and flooding:
- The flood lines are inadequate and the developers underestimate the risk of flooding. Evidence is presented that peak flows in the Jukskei River have risen 10-fold over fifty years and will continue to increase.
- The plans for managing storm water run off are inappropriate and inadequate – they ignore national, provincial and municipal guidelines.
Environmental authorization for the project was issued on 5 June 2015, subject to some conditions. The Environmental Assessment Practitioner for this project (GAUT:002/13-14/E0153) is Bokamoso Environmental.
See Linksfield development comment Irwin Juckes for comment on the draft.