Household Water Savings
Household level water savings, collection and storage solutions?
These have to play an important part over the long-term. By reducing water used at a household level the overall drain on the dams is obviously reduced. If everyone in the area just reduced their use of fresh water use from an average of 250 litres per day to 200 litres per day then it would be equivalent to adding two more Steenbras dams into the system. And it would cost virtually nothing to achieve this! Is this difficult to do? No! The experience of installers of water systems indicates that savings of 30% are actually easy, mainly by re-using ‘grey’ water. And such systems can often be D-i-Y installed at relatively low cost.
Other household contributions requiring some investment are the installation of tanks capturing rainfall from the house gutters, effectively creating small surface water “dams” in each home; and installations of shallow garden wells (10-15m deep) which in many Cape areas can deliver 1,000 litres or more per day of clean water good for non-drinking purposes over many months of the year (such wells recharge naturally from rainfall during winter and can run dry in late summer dry spells).
By capturing rainwater and installing a well, using the same tanks, it is possible for a household to become independent of the municipal water distribution system, except for potable water for personal consumption purposes – a minimal 5 to 7 litres per person per day. In a Utopian situation, if every household did this the average 4-person household fresh water needs would theoretically fall to below 1,500 litres per month, instead of the current monthly average of 30,000 litres, and the water in the existing dams would last for years and years; well beyond any dry spell.
Rainwater harvesting by households in SW Cape should be a part of any fresh water management solution.
Read more about how much water can practically be saved and economic considerations for rainwater capture systems here.
Installing some form of rainwater capture and water storage system at your home seems to be increasingly wise. At absolute minimum, one can probably get by on 25 litres per person per day. So a 4-person household can survive on about 100 litres per day for all purposes combined. A 1000 litre tank would last for about 10 days and, in the Cape between April and September, one should receive enough rain captured off a 60-80 sqM roof area to refill that tank 2-3 times per month.
And it doesn’t have to be sophisticated or complicated. The tank must be located on a firm hard, level surface as high as possible on the property to harness gravity for the outflow. Simple piping or flexible hose can be used to connect gutters to the tank and a hosepipe used to bring the water into the house. Rough rule-of-thumb is install 1000 litres of tank capacity per 60-70 sqM of roof area from which water is to be captured as a 10mm sharp shower of rain should then half-fill that tank.
At the moment (April 2017) 1000 litre tanks are available for about R2000, 2500 litre tanks for R2900 and 5000 litre tanks for R5150 and the piping will add a few hundred Rand more. Not cheap but worthwhile in the face of possible water outages. The basic question to ask yourself is “what will the alternative cost and effort be to fetch and transport water if the taps do run dry“?