Nearly 75% of Cape Town’s water is consumed at home so do your bit to reduce your water footprint until the winter rains come. Speak to neighbours first and then report them if they contravene the level 3b water restrictions. Everybody needs to work together to save water. Don’t let a neighbour wasting water be the reason that your tap runs dry.
Agriculture is not to blame for the drought. A drought by definition is below average rainfall and the reason why the drought affects our drinking water is because of an over reliance on surface water to supply our municipalities with domestic water.
Whilst water used by agriculture is high, there are some points worth mentioning
JOBS: About 8.5 million people are directly (638 000 formally employed) or indirectly dependent on agriculture for employment and income. The figure is so large because it takes into account dependents of farm workers.
WATER USE: South Africa is a large country, about a third of the size of the USA, however only 3% of the country has truly fertile soils and only 13% of the land being good for cultivation, while 69% is only good for grazing. This makes livestock farming the largest and highest income generating agricultural sector.
CROP AND ANIMAL WATER FOOTPRINT: The Table below from WWF-SA summarises the global water footprint of various crops. Green water is soil or rain water, blue water is irrigated water, and grey water is water polluted by the activity. So although Maize has a high global water footprint 77% of the water is from rain water and soil water. On the other hand, sugar cane, apples and nectarines have a much higher irrigated water footprint. Potatoes on the other hand have a much higher grey water footprint. Another issue with potatoes is that after harvesting the potatoes the field needs around 2 years to recover. In some instances, farmers plant maize and in other instances they leave the ground uncultivated so the soil recovers its nutrients quicker. TOFU has a global water footprint of 926 litres/kg, excluding importing the product from overseas suppliers.
Now where it becomes really interesting is when you look at the global water footprint and the nutritional content in order to calculate the water footprint (litres) per gram of protein when looking at red meat substitutes. Nuts have a higher water footprint per gram of protein compared to red meat, so you would be using less water if you had a packet of biltong than a packet of almonds for your protein. Nuts also contain more calories than beef. What is even more interesting is that eggs, chicken, pigs and sheep/goat meat have a low water footprints per gram of protein. Just note that these include the total water footprint, which includes rainfall/soil water and irrigated water.
Shelled almonds have Global Water Footprint of 16 095 m3/ton (Green: 9264, Blue: 3816, Grey: 3015), which is higher than Beef. Beef’s largest water footprint is from rainfall (green) compared to Almonds which have a higher irrigation footprint and pollution footprint. 80% of the worlds almonds come from California which is suffering a severe drought and the amount of water required for irrigation of almonds would be sufficient to supply 75% of the states population with drinking water, but because of water rights issued in the 1990s it has become a legal battle between farmers, citizens and the federal government over the water use.
FOOD SECURITY: When the rains fail the dryland crops fail while the irrigated crops continue to produce. During a drought the irrigated maize is vital to food security for human and animal consumption. Because of the failed crops, maize becomes scarce and the price increases. It then becomes an economic trade-off between using our scarcer water to produce our own crops or having to import maize from other countries who might be producing a surplus of maize. This would require further economic analysis to look at the cost of groundwater development, desalination, water recycling for municipalities (which would free up water for irrigation) versus the cost of importing food during a drought (PhD anyone?) The cost of water conservation and demand management is negligible which is why saving water is cheaper than having to import grains and meat. If we don’t save water we can expect to pay even more for our food and meat.
Because our municipalities require surface water for domestic supply, they are in direct conflict with agriculture for the same source of water. During a rainfall drought, irrigation should be predominantly with groundwater and not surface water. Groundwater droughts have a lag time behind meteorological droughts so groundwater can be exploited during the meteorological drought, and after the drought has broken then groundwater should be allowed to recover as surface water becomes more abundant.
FARMERS AND DROUGHT: Farmers understand this cost because it is cheaper to slaughter their cattle then it is buy livestock feed at elevated prices during a drought, especially the small scale farmers who do not have the capital and equity that the commercial farmers have access to. After the drought, if the farmers are not insolvent, they can start to rebuild their cattle stock when the price of livestock feed return to affordable prices or they can produce their own feed for their cattle. Farmers, who rely on the environment for their livelihoods are acutely aware of the drought and directly impacted by the drought as their crops fail (or reduced yields if irrigated) and livestock slaughtered with no source of income until government bailouts or insolvency occurs, while people in cities complain about water restrictions and not being able to use to wash cars, water gardens and fill the swimming pools. Let’s kick them when they are down and blame them for the drought too.
Not all Farmers are the same. Farmers are diverse as are their water use efficiencies. South Africa has some of the most water efficient farmers and some of the most water inefficient farmers. This is not a situation which is unique to South Africa. Even more baffling to me is rice grown for export in the Sacrimento Basin in California, USA, not only during a severe extended drought, but in an area which frequently has droughts.
SO WHAT CAN YOU DO?
Buy Grass-Fed beef. Grass-fed beef eat only grass and thus eliminate the need to irrigate crops for livestock feed and have a much smaller water footprint.
Eat lamb and mutton instead of beef. Typically lamb and mutton graze on natural vegetation and do not rely on irrigated crops, resulting in a lower global water footprint.
Do not go nuts about nuts. Nuts have the highest global water footprint after beef but in terms of blue water (irrigated water) footprint that are almost three times higher than beef and any other crop and animal product. As a protein substitute they have a very high water footprint per gram of protein. It also takes 4.2 litres (1.1 gallons) of water to grow a single almond, 80% of which comes from drought stricken California. The amount of water used to irrigate almonds in California would supply 75% of the states population with adequate drinking water.
Buy local. Do not buy imported products when locally grown products are available. This specifically applies to protein substitutes like tofu and almond milk. All you are doing is removing South African jobs, increasing your carbon footprint and transporting your water footprint to another country to deal with.
Eat less red meat. Yes, eating less red meat will reduce your water footprint, provided you stick to buying local alternatives so that the 8.5 million South Africans that are dependent on agriculture are still able to put food on their tables.
Don’t waste food. 34% of all available food is wasted while it is estimated that up to 1/3rd of household food waste is by consumers because they don’t understand the difference between the “sell by”/”best before” and “use by” dates. “Sell by”/”Best before” means quality and “use by” means safety. It is safe to consume food after the “sell by”/”best before” provided it has been stored properly. Consuming food after the “use by” date is risky. Read more here.
Cape Town is not expected to run out of water before the winter rains start.
Cape Town has 100 days of water left, so what does this mean?
Imagine this scenario:
Cape Town is our car, the fuel tank are our dams, and our fuel consumption is our water consumption. The petrol station are the winter rains that fill the tank.
So we’ve been driving our car for a while now and it’s been ages since we’ve seen a petrol station and our petrol gauge has gone from ¾ to ½ to 1/4. Now the Petrol Light is on and we only have 100kms (or days) left until we run out of petrol.
So no need to panic yet because we know that petrol station has always been open, every single time we’ve driven to it. Sometimes we are able to fill the tank to 100% if we are really lucky but most of the time we are able to fill the tank just enough to get us to the next petrol station.
So what do we do when the petrol light is on and we know we have just enough fuel to get to the petrol station? We drive fuel efficient! We switch off the aircon, close the windows, go easy on the acceleration, freewheel down hills…we also stick to the speedlimit and don’t speed. Now, we’ve been speeding for years and driving like a maniac – why? Because it’s fun and we’ve never really bothered about saving fuel before. We’ve gotten a couple of speeding fines before from government, and we’ve always just paid them because we have the money, and it’s easier to pay the fine than it is to change our habits.
Now the fines for speeding have become really expensive so there are penalties to driving fast and furious. So let’s be fuel efficient and stick to the speedlimit ok? Because we have to otherwise we are going to run out of fuel before we reach the petrol station.
But what happens if the petrol station is not where it always has been? What happens if it has moves down the road by a few blocks. (This is when we hit 20% dam level and the winter rains are late) or if we drive like maniacs and run out of fuel before the petrol stations.
Well just like a car, we have a reserve tank of 20%. BUT we don’t want to go into this reserve tank except for an emergency because like a car there are issues. Car manufactures always tell us not to run the fuel tank to empty. These tanks are full of sediment and when we reach that bottom 10% and start pumping out the sediment, well then we get sediment stuck in the fuel pump. Best case scenario we have to replace the fuel pump; worst case the engine seizes. Now this sediment isn’t normally a problem but only becomes an issue when the tank is empty. Remember, the solution to pollution is dilution. So like the dams, the sediments and nutrients become a serious problem at this stage.
To take the analogy further..
We’ve been driving our fuel guzzler vehicle for years because it’s what we’ve always driven and what we are comfortable with. The fuel price keeps on going up and up and it’s become more and more expensive to maintain and fill the car, but we still keep on driving it because it’s what we have always done.
We’ve driven past all the signs offering trade-in deals on our model, as well as great deals for hybrids and small models, but we like our car because it goes so fast when overtaking, and that’s fun. We’ve also been told the benefits of going green but still we stick to our car. We also know that we are in this exact same predicament every time our petrol tank light comes on, but still we stick to the same car we have always driven.
Maybe it’s time for an upgrade or a trade-in?
We know we need a large fuel tank because we have to have a lot of fuel storage because we stay so far from work. (Cape Town receives its rain in winter and has to store it until summer when it is needed). But there are other options. We can have a fuel efficient car for work, a bicycle for quick trips to the Spar down the road, we can also walk because that is healthy for us….we can car pool too or take public transport…
Get the picture? By relying too heavily on our dams we will always have this fuel light issue. And because of climate change, the experts tell us that fuel is going to become really expensive and harder to find. In order to become water secure, we need a portfolio of transport options.
The car (our dams) will probably always be needed to get to work but we don’t have to drive it all the time.
Cape Town has now implemented Level 3B water restrictions, so in our car we still had the aircon on full, we were overtaking, revving at the robots and in general heavy with that accelerator pedal. That petrol light has started flashing or the dashboard no longer tells you how many kms you have left, and we still don’t know if we will get to the petrol station before they close. So now is the time to really drive fuel efficient otherwise we might run out of petrol.
Communicating our science is one of the biggest challenges scientists battle with even without gag orders. This blog is my attempt at communicating some of the science. Please note that opinions are my own.
We should note that we are in a hydrological drought brought on by below average rainfall, which severely impacts CoCT because it relies 98% from surface water (dams) to supply drinking water.
So although we are in a hydrological drought, Cape Town still has water, Jim, but not as we know it.
Use less water. South Africa is water scarce as level 2 water restrictions should be the commonly accepted practice by all of us. A daily consumption of 250 l/day still puts South Africa as one of the largest water users (http://aspirenews.org/621/blue-zone/water/water-by-the-numbers/) despite our low rainfall. Using less water also makes more water available at zero capital costs which is perfect!
Stop flushing toilets with drinking water from the Boland. Crazy I know right? Perhaps all houses (especially new houses) should be designed to use grey water or rainwater to flush toilets and not drinking water. Flush toilets have been around for decades. Many improvements to the design have been done but these are not implement in large scale production – why? – because there isn’t the consumer need. Let’s start buying and demanding more water efficient toilets so they can start producing them full scale. Just note that currently our waste water treatment works rely on the dilution when flushing to treat effluent. Any large change would need to be done with an upgrade to the waste water treatment loads to insure they can handle the increased nutrient loads.
Decentralised water supply. Why rely on government for water? Why not capture your rainwater in winter and store it until summer to irrigate your garden. Why not use greywater (just make sure you aren’t polluting the groundwater resource)? Why not get a wellpoint or a borehole (Just note that groundwater and surface water are connected – one resource. So don’t waste groundwater).
What Does Cape Town have planned:
CoCT has planned the following: The first additional scheme is Voelvlei Augmentation Scheme which will come on around 2021 when additional water will be pumped from the berg River into Voelvlei Dam.
A City project is the reuse project – to be in place by 2023 – 100 mega litres of waste water recycled to drinking standard in the first phase.
So how do you increase water security in a changing climate? We need alternate water resources, so if one fails or is under pressure like surface water during a drought, we increase the usage of the water sources, and then go back to sustainable use afterwards.
No more dams – Cape Town is already 98% reliant on dams, hence the current predicament of our severe drought. Drought frequency and intensity is also expected to increase with climate change. The annual average potential evaporation for Cape Town is between 1400mm and 2200mm. So for a standing body of water, between 1.4m and 2.2m evaporates every year (this applies to swimming pools which don’t have a cover on it too)
Desalination – Things to consider: Where does the water come from, where does the energy come from, where does the water go, where does the waste go, cost.
Costs continue to decrease (but it is still expensive). Desalinating sea water is costlier than saline water and produces more brine. South Africa is still in an energy crisis so should we be diverting our precious energy to produce drinking water if there are alternate and cheaper water? Desalination should not be done using coal fired energy from Mpumalanga because this moves the high water footprint to another part of the country and doesn’t solve the problem. Water is used to mine coal, wash coal and used by the coal fired power stations as a coolant. In addition water is polluted by coal-based activities in the form of acid mine water and acid rain. There are also massive transmission loses as the electricity is transported across the country in the power lines. Koeberg and Nuclear Power is an option. Koeberg is by the ocean and generates electricity that can be used without transmission loses. The issue would be transporting the water from Koeberg to Cape Town. The pipeline between Atlantis and Cape Town only runs in one direction (from Cape Town), despite Atlantis having an abundant groundwater resources and artificial recharge scheme. But should we invest in desalination from nuclear power when the future of nuclear is so uncertain in South Africa, and fraught with allegations of corruption. So desalination costs a lot in terms of capital expenditure and maintenance and should we be investing money in it when there are cheaper water resources?
Rainwater Harvesting. Rainwater harvesting is a decentralised or individual option. It is easy to capture winter rainwater in jojo tanks, and then store it until it is needed. Rainwater harvesting can become a municipal requirement for all new developments. There are issues with the long storage time and the growth of bacteria, especially during the host summer months, so would not recommend using rainwater for drinking water. Just note that the rivers require rainwater to dilute the urban pollutants so if all rainwater was captured our rivers would become heavily polluted.
Stormwater. Currently our stormwater is flowing out to sea and could be captured and used. This water would have a high cost of treatment as our cities are dirty. UCT is looking at future city options like permeable pavements to filter and treat the stormwater before it enters the drain. Just note that the rivers require stormwater to dilute the urban pollutants so if all storm water was captured our rivers would become heavily polluted.
Recycling water. Recycling water is a very good option. No transport of the water is needed as it is already in the urban system. The problem is the public is against drinking recycled water and does not trust that it is clean and safe to drink. Whilst there are complicated pharmaceuticals and endocrine disruptors in our waste water, these can be monitored and mostly removed if the water is going to be used for drinking water. Treating water back to drinking water quality is costly, but it is cheaper to treat it for the purpose which it can be used, such as irrigation or industrial use….or for flushing toilets (yes I keep on getting back to that).
Groundwater. Groundwater yes it can! Does Cape Town have a lot of groundwater? Yes. There is the Capfe Flats aquifer, Table Mountain Group Aquifer, Newlands Aquifer, Atlantis Aquifer, Camissa Springs, Newlands Spring etc. etc. etc. While surface water is stored in Dams, groundwater is stored in aquifers…which means….no evaporation! Groundwater does not suffer from the massive evaporation loses like surface water dams…also the rock or sand (which makes up the aquifer) generally provides a filtration function and purifies the water. Are we drinking groundwater already? Yes! Most of bottled water is spring water which is…groundwater. SAB Newlands brewery uses pristine spring water from the Newlands/Albion Spring in its beer. Table Mountain Ground Aquifer is also excellent quality water. But, like surface water, not all groundwater is of drinkable quality and some require treatment. The Cape Flats aquifer, thanks to apartheid land planning practices, has had its quality heavily impacted. So with the Cape Flats aquifer, we have the water but it would need treatment in order to be used. Consequently, one of the reasons that Cape Town always has floods in winter in the informal areas is because the groundwater in the Cape Flats aquifer is not being used. Instead the water table is sitting close to the surface so by the end of the winter rainfall, the rain cannot seep into the ground and instead floods of the surface – so although it might be costly to treat the Cape Flats aquifer, by dewatering it we mitigate our winter floods in the informal settlements on the Cape Flats as well as the health impacts of the annual flooding.
So why isn’t groundwater being used more?
People, politicians and engineers love dams. They’re charismatic and people can see that government is doing something about it. Which headline would make you feel good “Government spends billions building a new dam” or “Government spends millions drilling a few boreholes”
Groundwater is underground so it cannot be seen, unlike a dam which is easy to see and monitor. Groundwater can be monitored and utilised, especially by groundwater specialists.
People know dams but don’t know groundwater (despite drinking a lot of it).
Groundwater is much cheaper to develop in terms of capital investiture compared to building a dam, but still the public perception (which influences the political decisions) is that dams are the answer.
We have the expertise for groundwater in Cape Town (University of the Western Cape) but civil engineers have the partnership with the construction firms, and we all remember the collusion with the “construction cartels” for the World Cup in the building of SA’s soccer stadium. That’s quite a machine to go up against….
So, what are you doing to make yourself water secure?
Whilst groundwater can be the answer to Cape Town’s water supply issues, there are some key points that I would like to point out about the articles on the springs in the City Bowl:
Freshwater flowing out to see is NOT wasted
Although the Table Mountain Marine Protected area only starts at Mouille Point, I would imagine that the springs play an important role in diluting the pollutants from the harbour in Duncan Dock and Table Bay. Take a read of the first guideline of freshwater conservation planning from the Freshwater Ecosystem Priority Areas project:
“Freshwater inputs to estuaries and the sea are necessary to maintain important ecological processes that keep our marine resources healthy. For example, fresh water provides an important environmental cue that helps fish and other marine animals find their way to estuary mouths to breed. Nutrients in fresh water also form the foundation of marine food webs. These ecological processes are vital for maintaining commercial and recreational fish stocks, as well as for providing a source of food to poor coastal communities that depend directly on marine resources for food. A certain amount of water is also required to flush and scour the mouth of most estuaries. Without the scouring effect, sediments build up at the mouth and the risk of back-flooding during storms increases. Artificial breaching of an estuary mouth to minimise this risk is expensive and damages estuarine ecosystems. Apart from the scouring effect, fresh water helps to flush estuaries of organic matter and other pollutants, which otherwise smell unpleasant. If too much water is taken out of a river along its length, not enough fresh water reaches the estuary and the sea to maintain these vital ecological processes.” Available from http://bgis.sanbi.org/NFEPA.
A combined spring system of 40 Litres/second is only able to supply 1382 people with the average water consumption (based on 250 L/day).
Oranjezicht springs are 28 litres/second, and combined with formal springs increase to 40 L/s (http://www.dwaf.gov.za/…/…/WMA/19/WCWRSNewsletterMarch09.pdf). 40 L/s is equal to 3,456,600 litres/day and 1.262 million cubic metres (mcm) per annum (http://www.convert-me.com/…/…/flow_rate_volume/liter_s.html…) . Assuming the water could be treated to drinking water quality, the average daily consumption for South Africa is 250 l/day, which means the springs would be able to supply 1382.4 people with 250 l/day. And that’s 1382 people in Gardens or Oranjezicht, not on the informal settlements on the cape flats where it is needed (like the Huffington post comments. I doubt he would be driving through oranjezicht and kloof nek thinking that these wealthy residents need more water…)
The Western Cape Water Supply Scheme has a gross capacity of 904 mcm (million cubic metres) while City of Cape Town has a demand of 399 mcm, compared to the spring supply of 1.262 mcm per year.
The Berg River Dam is 127 mcm, Theewaterskloof is 480 mcm, Voelvlei is 172 mcm and Wemmershoek is 59 mcm. So the springs are insignificant compared to the volume of water required for City of Cape Town. However, for the city bowl, Woodhead Reservoir has a capacity of 0.927 mcm and the Hely-Hutchinson Dam is 0.95 mcm so it is locally important water resource, but again do the residents of Oranjezicht and Gardens need more water?
The Springs cannot be used for domestic drinking water.
The springs have been polluted and are not drinking water quality and haven’t been since the 1890s when it was diverted into the sea for that very reason. The water would need to be treated before it can be used, which would increase the cost of using it, making it unviable.
Springs can be used for irrigation rather than irrigating with drinking water.
The studies 2008 studies note that the volume is “more than sufficient to meet the annual irrigation needs of the Common, Green Point Stadium, the Metropolitan Golf Course and Mouille Point Beachfront. And so, the city could, once again, to some extent at least, be connected to the sweet waters of Camissa.” Greenpoint urban park uses the water from the springs. The park has an annual requirement of 0.58 mcm. As far as I remember when they designed Cape Town Stadium they designed it to use City of Cape Town water, so there would be a cost involved in diverting water and redesigning their system.
Most of the irrigated areas in the City Bowl and the Southern Suburbs use existing cheap sources of water (like boreholes)
There are not many areas under irrigation in the city that use drinking water. Most of the schools use borehole water (groundwater) to irrigate, which at the moment is free (in terms of volume) with the main cost being the drilling of the borehole. There are some schools with green fields, but it is not financially feasible to pipe this water to school fields and then to charge schools for the water while they are now getting it for free. Also the schools aren’t income generating so it isn’t socially fair to burden schools with additional expense. This is especially true for the Southern Suburbs and the Albion/Newlands spring. That spring has a much higher yield but there isn’t a need. City of CT is looking at reconnecting the Albion spring to the water supply network. Although currently this spring is diluting the pollution in the liesbeck river so removing it could cause huge pollution problems for the Liesbeck.
So overall I feel that Camissa has become an emotional issue rather than fact based.
City of Cape Town is award winning in terms of its water management (The City of Cape Town was presented with the C40 Cities Award for “Adaptation Implementation”, recognising the City’s Water Conservation and Demand Management [WCWDM] Programme, ) and has been proactive in looking at additional water resources to augment future water supply.
Because of the Water Conservation and Demand Management programme, Water Demand peaked in 1999 at 335 mcm. The 2014 water demand was 318 mcm. So since 1999 CoCT has been able to reduce its water consumption despite massive population growth and better water service delivery. (http://www.watersummit.co.za/…/24June2015_6b_Paul%20Rhode.p… )