GARDAG Water Monitoring Results 2024

In OUR backyard - George

In the past, GARDAG undertook a series of water samples to refine our understanding of impacts from urban pollution and potentially Stage 6 loadshedding on the Garden Route area.

The tests were undertaken over a period, at points that were highlighted as impacted.  Ideally these tests should be undertaken on the same day of every month, but time and financial limitations dictated the monitoring frequency. During 2024, monitoring was increased and some of the active monitoring points are measured more regularly. This post discusses the results from the previous monitoring events, up to November 2024.

WATER MONITORING RESULTS 2024

In OUR backyard - George

In the past, GARDAG undertook a series of water samples to refine our understanding of impacts from urban pollution and potentially Stage 6 loadshedding on the Garden Route area.  The tests were undertaken over a period, at points that were highlighted as impacted.  Ideally these tests should be undertaken on the same day of every month, but time and financial limitations dictated the monitoring frequency. During 2024, monitoring was increased and some of the active monitoring points are measured more regularly. See the map at the end for the current active monitoring points. Pertinent results are shown in the graphs below and discussed in the sections to follow.

Kat River

The Kat River, a tributary that flows into the Garden Route Dam has a history of untreated sewerage water seeping into the river from either broken household (urban) level pipes or from the Eden Sewerage Pump station overflows.  GARDAG started monitoring this river in response to complaints received. Limited laboratory analyses were done as funds allowed, until the WaterCAN test kits became available, and monitoring could be performed more often, on a screening level. The Kat River Results graph shows the E.coli and total coliform bacteria counts as was grown in petri dishes, with the phosphate levels that sometimes reaches 100ppm or higher.

E.Coli and total coliforms are groups of bacteria that occur naturally in river system, however, when an external load like seeping sewerage water, contributes to the levels in the river an unnatural growth pattern can emerge and lead to eutrophication of the fresh water source. In the Kat River case, a decrease of nitrate/nitrite with an increase in phosphate is a warning indicator for potential eutrophication. The nitrate with oxygen is a fuel source for bacteria and when oxygen is depleted below a critical level, the water source becomes oxygen depleted and the eutrophication process explodes exponentially. This is a scenario best avoided, and correction of the source problem is the solution.   

Garden Route Dam

 The nutrients in the Kat River, specifically the sections where polluted water from urban sewer systems seeps to the river, feed the Kariba weed and water hyacinth that periodically flourishes in the Garden Route Dam.

The only long-term solution to treat this and reduce the growth of Kariba weed, would be to increase the oxygen and microbial activity in the water of the Kat River or reduce the nitrate/nitrite load from the urban areas.  This is a red flag for potential eutrophication of our main water source and one of the main reasons why GARDAG believes that there should not be further urban development within the catchment area of the dam.

The GR Dam Results graph shows the E.coli and total coliform bacteria counts as was grown in petri dishes, with the phosphate levels that reached >100ppm, for the first time in our monitoring data, during June 2024. Fortunately, the WaterCAN results in August & September 2024, for both the Kat River and the Garden Route Dam, showed a significant decrease in phosphate levels, possibly because of better municipal sewage management upstream.

George Rivers

The Meul, Skaapkop and Gwaing Rivers below the general town areas was added to the active monitoring points during 2024. Data for the 2 monitoring periods are shown in the graphs to follow.

The Meule River petri film developed a purple bacterial grass mat where individual colonies could not be identified. Although some total coliforms were seen in one film, a dense growth like this is considered a very polluted river and given a score of 500 (for illustration purposes).  The Meule River downstream of the town area is the worst polluted river that is being monitored by GARDAG in the Garden Route area.


Both the Skaapkop and Gwaing Rivers show similar pollution levels with a significantly higher count of E.coli in the Skaapkop River in July 2024. The reason is unknown. Phosphate levels are also in the 100ppm or higher range.

River Mouths

The Gwaing, Kaaimans and Touw Rivers, all popular tourist destinations during summer, was sampled during 2023 to determine the safety of these popular swimming spots.  E.coli levels were found to be low (below 10 cfu/100ml), partly due to the rising tide that would dilute and sterilize the E.coli in the water.  Unless failure of municipal control on raw sewerage input into the river systems occurs, these areas should remain open for recreation during the summer holidays. Closure of these beaches is a direct result of mismanagement / overload of local sewerage systems and something that can be avoided with proper planning.

Watchdog

Water monitoring was previously done in response to complaints, whether it be once off monitoring or trend monitoring, but changed to establishing long term trends in our water resources. The Garden Route area is at a turning point in terms of development versus available water resources and monitoring needs to become more scheduled and in line with the intended objectives. GARDAG appreciates the work of the George Municipality to manage our water, but will continue to monitor the strategic water resources of George for undesirable trends. For this reason, it is for the public’s benefit to support the monitoring activities of the NPO through volunteering, donating or sponsoring various activities.