Free water

A Meadowridge security complex will soon shut off its municipal water supply in preparation for Day Zero.

El Meadows, a complex of 26 units located behind Park n Shop, held a closed meeting on Wednesday November 22, with the Bulletin being denied access and told it was a “private meeting, for residents only”.

The Bulletin was told that, after a presentation by one of its residents, a water engineer, they gave the green light to totally go off the municipal water system. They will provide suitably purified and treated water from their borehole.

The following day, chairman of El Meadows body corporate, Gerald Lyons, said the trustees were looking at quotes. Once commissioned, all water in the complex, for domestic use and irrigation, would be supplied by the borehole.

However, a resident at El Meadows, who does not wish to be named, is against the project, saying it will affect the underground water supply of about 300-odd houses surrounding the complex, between Newton Drive and Bergvliet Road.

He said a well point with the pump at ground level can only draw water from up to 10 metres (as a result of atmospheric pressure).

El Meadows’ borehole is about 45 metres. With the submerged pump supplying the volume of water required for the complex, the lowered local water table would starve surrounding well points, he said.

Roger Graham, chairman of the Friends of the Meadowridge Common, is also opposing the move, saying groundwater is not private.

He also tried to enter the meeting but was refused. “Having a full-on system such as that envisaged at El Meadows will impact not only surrounding boreholes and well points but also lower the water table,” said Mr Graham.

He said many properties had boreholes and used the water for gardens. “Which results in most water returning to the soil and the aquifer. El Meadows’ proposal, however, will result in much of this water going down drains and no longer back into the earth,” said Mr Graham.

He recalled a 2015 AGM of the Bergvliet Meadowridge Ratepayers’ Association (BMRA) where Dr Tony Rebelo warned that too much depletion of the Cape Flats aquifer would result in the groundwater there becoming saline owing to the proximity of the False Bay waters. “Now this continuous drain on the groundwater will affect our natural environment for the worse. El Meadows’s proposal is not only irresponsible but it also has wider impact,” said Mr Graham.

Asked if the principle still stands, Dr Rebelo said: “Yes, if too many people use too much water, salt water incursion into the aquifer will occur. But the City is monitoring this and coastal residents will rapidly detect this if it happens,” said Dr Rebelo.

Mr Lyons said the cost of El Meadows going off-water grid is about R254 000. They estimate this to be a good move what with the free water allowance being removed and the City and Department of Water Affairs stating that restoring adequate water supply would mean future increases in the cost of water.

Dr Kevin Winter of UCT’s environmental and geographical sciences department said anyone using more than 10 000 litres of borehole water a month required a water licence.

The City of Cape Town does not regulate borehole usage, as it falls under the mandate of national government.

Groundwater specialist Ernst Bertram explained why those who use more than 10 000 cubic meters of surface and groundwater must be registered. “It’s the groundwater use you’re registering, not the borehole,” said Mr Bertram. Anyone who contravenes registration and payment could face a fine or imprisonment for up to five years.

Gabby De Wet of De Wet’s Boreholes said many complexes and private homeowners were doing what El Meadows is working toward. “We recommend the considerate and sparing use of any water, no matter the source,” she said.

The water level should not be affected if everyone does this. However, a borehole drilled close to a neighbour will affect the flow of both boreholes.

Chairman of BMRA Mark Schafer said they were aware of El Meadows’ plans and would discuss it in their December committee meeting. “The question is whether they are encroaching on anyone’s rights or obligations regarding borehole usage and its impact on underground water supply to neighbouring properties,” said Mr Schafer.

What the experts say

Dr Kevin Winter of UCT’s environmental and geographical sciences department said over abstraction from the imminent drilling of boreholes into aquifers on Table Mountain and on the Philippi Horticultural Area (PHA) could have a disastrous long-term impact on the environment. “Tall trees starting to wither, die and fall over, as well as lakes and rivers ceasing to flow are the first signs of over-abstraction of groundwater,” said Dr Winter.

“Domestic gardens would be abandoned and become increasingly covered by hardened surfaces resulting in elevated urban temperatures. Levels of dust particles rise and so do lower levels of atmospheric temperatures. With an increase of contaminants in confined bodies of water, surface water quality deteriorates,” said Dr Winter.

Umvoto Earth Sciences consultancy director John Holmes said the total yield from groundwater extraction remained unknown. Umvoto has partnered with the City to develop the Table Mountain Group Aquifer and Cape Flats Aquifer for groundwater abstraction.

Hydrologist and director of Geoss (Geohydrological and Spatial Solutions) Dale Barrow said a lot of underground water in aquifers was contaminated and that on the Cape Flats, water was in the sand that underlies Philippi and Muizenberg and not free flowing.

Executive manager at the Water Research Council (WRI), Dr Shafick Adams said South Africa had one of the highest per capita water use in the world. The average is 170 litres a day, compared to our average of 235 litres, and in some metropolitan areas it can reach 600 litres a day.

“Groundwater is an invisible resource to the layperson. It’s difficult to determine its volumes as opposed to a dam. This leads to a perception problem about its assurance of yield – it needs to be developed and managed by skilled personnel,” said Dr Adams.

He said a WRI study recently surveyed 24 municipalities that used groundwater as a domestic supply source, and found that 71 percent of them did not had a groundwater management plan, while 17 percent did not know if they had a plan.

Groundwater, boreholes, aquifer

Boreholes are drilled by means of an hydraulic rig, either mounted on large trucks or on trailers, which makes them more accessible to residential properties. Borehole depths vary between 20 and 120 metres and beyond, depending on the area. Boreholes are equipped with a submersible pump. A borehole is the mechanism through which the groundwater can be accessed and/or abstracted from the aquifer.

Well points are installed manually and are equipped with surface-mounted centrifugal pumps. The depth also varies depending on ground structure but usually not beyond 10 to 14 metres.

Groundwater is the water contained in an aquifer.

An aquifer is a geological formation which has structures or textures that can hold water or permit appreciable water movement through them to the extent that it can be abstracted economically.

Source: De Wet’s Boreholes.