Frequently Asked Questions

For single sample thresholds the City of Cape Town uses a colour-coded rating system to provide information on coastal water quality. Green means the water is within the National guideline thresholds. Amber means the latest sample exceeds National guideline thresholds. Red means a beach's waters have experienced two consecutive samples exceeding National guideline thresholds. In this instance users are requested to exercise caution until the next sampling result is established.

For longer term 365 day rolling periods the City uses the following colour coded categories: Blue (Excellent) reflect consistently good water quality and low health risk for swimming and recreational activity. Green (Good) reflects generally good water quality, with occasional elevated results. Amber (Sufficient) means that water quality meets the minimum guidelines for acceptable recreational use, but elevated results occur more often. Red (Poor) means the beach does not currently meet the guideline for acceptable recreational use.

Most of the City’s 72 recreational beaches are sampled once a week. Sampling frequency is reflected on each of the beaches listed on the web page. Results are updated on this platform as soon as they are processed by the laboratory.

The long-term classification uses a rolling 12-month window of all test results to categorise each beach as Excellent, Good, Sufficient, or Poor. It gives a picture of overall water quality over time rather than just the most recent sample.

Enterococci are bacteria found in the gut of humans and warm-blooded animals. Their presence in seawater indicates contamination by sewage or stormwater. High levels can cause illness, particularly in young children, the elderly, and people with weakened immune systems.

Please consider the content and information contained in the alert as each alert will be unique. Alerts will provide information as to which beach is affected, the time and duration it may be affected, cautionary notes etc. Alerts may also be generated to provide users with interesting information on coastal phenomena along our coastline, such as the presence of whale supergroups, red tides etc.

Water quality can change quickly due to various factors. For example, it is a well known phenomena for water quality to decline after rainfall. This is because rainfall  washes surface run-off and stormwater into the sea and this runoff typically contains polluted water. Other causes include wastewater and sewage spills, seasonal environmental factors etc.

You can report concerns to on the City’s online service request portal, call the 24-hour contact centre on 0860 103 089 or send an email to beach.alerts@capetown.gov.za.

The City has an extensive stormwater network that is designed to prevent the flooding of roads and the built environment during rainfall events. The rainwater enters the stormwater system through inlets on the sides of the roads, and is then channelled underground, and transported via stormwater mains to the sea. This runoff is not treated, or diluted, but goes straight into the sea.

The only substance that should end up in the stormwater network is runoff during and after rainfall events. This means, if it has not been raining, nothing should flow out of the stormwater system. But this is, unfortunately, not the case in most coastal cities.

Some residents and businesses use the stormwater system as a convenient means of disposing pollution – be it domestic animal waste, fats, oils, industrial coolants, or other pollutants. All of this waste enters the receiving marine environment and can have a significant impact on water quality, especially adjacent to these outlets. This explains why water quality is poor in coastal areas close to stormwater outlets and especially after rainfall events.

The extent and severity of the misuse of Cape Town’s stormwater system – either knowingly, or because of ignorance – is evident from the following two examples.

The first was from a pilot study conducted by the City to test the feasibility of an environmentally friendly method of exposing stormwater outflow to UV light to sterilize the stormwater before it enters the nearshore coastal environment.

Unfortunately, the UV bulbs were covered in fats and oils within hours, and in the end, it rendered the project ineffective and the pilot study did not progress beyond this stage. These fats and oils that smothered the bulbs originated from the restaurant industry discharging significant quantities of these substances into the stormwater system.

The second example was when the City found industrial coolant entering a stormwater drain in Adderley Street in the middle of the Cape Town CBD. The City traced the source of the discharge to the top of a multi storey building where it was being used in an industrial cooling system. Having engaged with the various operators of the building it came to light that it was "industry standard" to discharge excess coolant into the stormwater system, despite it being unlawful to do so.

Although the incident may have taken place in Adderley Street in the centre of town, this liquid ultimately found its way to the sea via the stormwater system.

These two examples and real events reveal the systemic challenges that we face as a coastal city in respect of managing, and improving, coastal water quality in Cape Town. We need businesses and industry to respect the stormwater system and to dispose of waste in a responsible and sustainable manner. Pollution is everybody’s problem. Any long-term solution should be founded on a collective response and a shared responsibility between all of us who live and work in Cape Town.

The term ‘dilution’ refers to the process of reducing the concentration of a pollutant by mixing it with uncontaminated seawater to reach an acceptable level for ecosystems, and for recreational activities such as swimming.

In the marine and coastal environment, dilution and the effect of waste streams or pollution is determined by specific coastal and oceanographic characteristics which are unique to any specific coastline.

If the Atlantic coastline is considered versus the False Bay coastline, both have unique and distinctive physical characteristics and coastal processes. Therefore, the behavior and dilution of similar waste streams will vary significantly when discharged along our Atlantic coastline versus our False Bay coastline.

So, what are the main differences between our Atlantic and False Bay coastlines?
It is the wave climate and dominant wind directions; the water depth;  coastal geomorphology and oceanographic processes. The Atlantic coastline is directly exposed to westerly waves; while the False Bay coastline is partly sheltered. Thus, there is less wave energy in False Bay (relative to the Atlantic seaboard) and this limits the dilution and transporting capacity of waste streams. In terms of dominant wind directions, in summer the southerly and south-easterly winds blow directly onto the northern and southern coastline in False Bay, which can trap any waste stream within the surf zone. Whereas along the Atlantic coastline, the southerly and south-easterly winds blow offshore.

In terms of seabed depths, otherwise referred to as ‘bathymetry’, it is significantly shallower in False Bay. This results in smaller wave heights, therefore again, les wave energy. With the reduced wave energy, as well as the shallower bathymetry, the assimilative capacity in False Bay is less. Basically, what that means is that False Bay has less capacity to ‘cleanse’ itself.  The presence of offshore reefs along some sections of the False Bay coastline means that polluted water can also get “trapped” inshore of these reefs for longer periods of time before the pollution is assimilated.  

In summary the False Bay coastline has less capacity to deal with waste streams or pollution compared with the Atlantic coastline due to the different physical characteristics and coastal processes evident along these coastlines. 

Cape Town is a relatively large, industrialised city. All of us living and working here, along with visitors to the city eat, buy, produce and dispose of waste in this environment on a daily basis.

Collectively, the city produces approx. 500 million litres of wastewater per day. All of this waste or pollution finds its way into sewers, the stormwater system, rivers, and ultimately the sea as the receiving environment. 

The city relies on its sewer network and wastewater treatment works, together with the assimilative capacity of the environment, to assimilate this wastewater effluent on our behalf. However, it is increasingly being recognized around the world that this approach is not sustainable.

Understanding the full dimensions of the challenge allows us to develop appropriate responses to try to limit our collective impact on our environment and coastal waters.

Clearly new approaches are needed.

We all have to admit and acknowledge that we have an impact on the environment, and we have to develop a collective understanding of the extent of this footprint. With this understanding comes the reality that we will have to change our collective behavior in relation to how we consume, produce and dispose of waste. We need a shared sense of responsibility to work together to find and implement more sustainable solutions.