Cape Argus / 16 November 2011, 8:29pm / Bronwynne Jooste
Capetonians could face stricter water restrictions as dam levels hit a four-year low.
Low-level restrictions are already in place including a ban on watering gardens between 10am and 4pm.
Adding to the low dam levels, rainfall this year has also been below average.
A UCT climatologist said of the past 10 months, eight had had below-average rainfall. May, June and July, usually the wettest months, were “drier than normal”.
Climate models showed this situation was likely to become more common in the years ahead and it could drive up the price of water.
Residents were being urged to conserve water. This appeal comes as climate change is expected to lead to rising temperatures and changes in rainfall patterns.
The City of Cape Town’s water department was due to meet the Department of Water Affairs and Forestry on Wednesday but has not released any details.
The city’s draft annual report says 19 percent of water was “unaccounted for”. This term refers to the difference in the amount of water purchased and in the city’s distribution system, compared with the amount which is sold to customers.
The report for the past financial year calls for measures to prepare for a “water-constrained future”. Some of the alternatives are desalination of sea water and the greater use of groundwater.
According to the draft report, some water-saving techniques are showing results. One of these is a pressure-management system which reduces the pressure of the water supplied to city consumers during off-peak periods.
This results in fewer leaks. A project like this at Brown’s Farm in Philippi produced an estimated saving of R8.2 million annually. After the project was introduced, there was an immediate drop in consumption.
Levels of the six major dams supplying Cape Town are at the lowest they have been in four years. On November 7, levels stood at 86 percent. Last year at this time they were at 93 percent and at 102 percent in 2009. Levels peaked in 2008 at 103 percent and were 99 percent in 2007.
Farouk Robertson, spokesman for the city’s water and sanitation department, said the city had “never relaxed” its appeal for residents to use water wisely.
Robertson said the city had expanded rapidly over the past few years and economic activity had increased.
This had led to more water consumption.
He urged residents to “amplify water conservation efforts”.
One tip was that residents should monitor the moisture of the soil in their gardens and, if necessary, introduce composts which would reduce the evaporation of water.
Another measure was to use buckets to wash cars, instead of hosepipes.
Robertson appealed to home-owners to watch their water meters and report leaks immediately.
“If you are wasting water, you are depriving other people of good quality drinking water. Know what you going to do, before you open the tap,” he said.
Peter Johnston, a climatologist with UCT’s Climate Systems Analysis Group, said for May, June and July, rainfall was less than 80 percent of the long-term average.
Johnston added that as December approached and it got hotter, around 1 percent of the volume of dam water would be used or lost due to evaporation each day. Because, November had been cooler, it had lessened the impact of evaporation.
“This is the sort of thing we can expect. We should get used to this scenario occurring more often and it’s a call for all us to watch our demand and usage.”
The Department of Water Affairs and Forestry was not immediately available for comment.