The Soet River, which originates in the Hottentots Mountains and flows down through the Lwandile and Nozamo informal settlements before reaching the sea at the Strand, is so polluted that not one water sample taken by the City over a 12 month period adheres to minimum water quality guidelines.
This is contained in the City’s Inland and Coastal Water Quality Report recently circulated amongst the sub-councils, which notes that of the 27 different river and water body systems, only one river, the Schusters River, had 100% compliance with the intermediate contact recreational guideline.
“The Soet River in the Strand area had zero percent compliance – this means that sample results during the 12 month period were all greater than 1000 counts (of faecal coliform – including E. coli)/100ml,” states the report.
The reasons given for this are that it has a small catchment which is “undergoing rapid development and there are reports of periodic blockages/failures of the sewer reticulation system” which results in overflows into the river resulting in unacceptably high bacterial levels.
The Big and Little Lotus Canals, and the Diep River and Canals, also faired very poorly, with eight and 24 percent compliance respectively. They both flow into recognized recreational areas, with the Diep River flowing into Rietvlei and the Milnerton Lagoon, which had a compliance rate of 21 percent, while the Big and Little Lotus Canals flowed into Zeekooevlei, which had a compliance level of 70 percent.
The report also shows a long term decline in inland water quality since 2000, when 80.5 percent of the systems complied with quality tests, whereas the latest compliance figure was only 55 percent, which is about where it has been sitting since 2005, except for an improvement in 2007, when there was a 62 percent compliance.
Regarding coastal water quality, 17 beaches in False Bay failed to comply with the stringent Full Contact Recreational Standard contained with the SA Water Quality Guidelines for coastal marine waters.
Beaches to avoid include the Kalk Bay Harbour Beach, Muizenberg Station and Pavilion, Mowabisi Beach, Macassar Beach, and virtually all beaches in Strand and Gordon’s Bay, including the popular Bikini Beach.
On the Atlantic coastline, four beaches failed to comply with the standard, namely: Three Anchor Bay; Rocklands Beach; Sunset Beach pool; and Saunders Rocks Beach.
While long term measurements on the Atlantic side show the most recent results are the same as those in 1992, there has been a decline on the False Bay side.
Water quality measurements for False Bay coastline in 1992 show an 86 percent compliance, while the most recent report indicates a 58 percent compliance.
However, there has been a slight improvement from a low of 50 percent compliance in the July 2007 – June 2008 reporting period.
For coastal water quality, the report did not provide the compliance status statistics of beaches awarded Blue Flag status as their monitoring was done through a separate programme undertaken by an external laboratory.
City’s Roads and Stormwater director Henry du Plessis said the city was upgrading infrastructure such as Waste Water Treatments Plants in order to improve inland and coastal water quality.
Du Plessis said upgrading infrastructure was expensive and limited to what could be achieved within the allowable budget. It was thus a medium to long term process and not “a quick fix issue”.
Senior hydrologist Arthur Chapman at sustainability company OneWorld Sustainable Investments, said poor water quality substantially reduces aquatic biodiversity, which had a negative impact on the environment.
It also impacted on human health and security.
Chapman said poor water quality was usually as a result of contamination from untreated sewage, and “people drinking such water will experiences gastrointestinal illness”.
He said reducing sewer blockages and the resultant discharge into river courses was the “prime response” needed to improve water quality.
“A lot of expensive work needs to be done to upgrade the sewer systems and waste water treatment plants in the Cape Town region to cope with increasing populations.”