KNYSNA NEWS – Over the past few months the Knysna-Plett Herald (KPH) has received a number of letters regarding readers’ concerns over Knysna’s water woes.
The Knysna municipality implemented Level 2 water restrictions in December 2016, but further research shows that the greater Knysna has been under some sort of water restriction since 2006.
In a press release issued by the municipality on January 26, the following restrictions applied:
• An additional 50% of the approved water consumption tariff will be applied on all punitive water tariffs to be billed. This means that all water usage above 20kl/month will be charged at 1.5 times the normal tariff.
• Knysna municipal potable water is restricted to human consumption and business use only, which means no watering of gardens, washing of vehicles or boats, etc is allowed.
• Businesses in the Greater Knysna will need to implement water recycling systems. Artificial water features and fountains are permitted to use only recycled water.
• All residents are required to retrofit their taps, showerheads and other plumbing equipment with water efficient devices.
Because there are so many different questions, and opinions on how to solve what is seemingly wrong with the town’s water situation, KPH spoke to Knysna municipality’s deputy town engineer: water and sewage Rhoydon Parry, to see what light he could shed on the matter.
History plays a big part
“The fact that the Greater Knysna has been under some kind of water restriction for so long is because of the way Knysna has developed in the past.
The more the town grows, the higher the demand for water supply becomes. At the moment the demand is slightly higher than what the system can supply, mainly through the Knysna and Gouna rivers, and that is why we need to supplement the water supply by pumping water from the Akkerkloof Dam,” said Parry.
“If we were solely reliant on the dam, the town would only have 35 full days of water available, but unlike Cape Town our main supply of water does not rely on the dam but on the rivers around us. As long as the rivers around Knysna still run we will have water,” he added.
Water supply not guaranteed
“We need to be able to assure the supply of water, but at the moment we cannot guarantee the supply. Therefore water restrictions are imposed,” said Parry.
The current demand for water in Knysna, according to Parry, is 12.3Ml/day while rivers and boreholes can only supply 11.4 Ml per day. During the festive season the demand sometimes increases to 18.1Ml. “The difference is made up by water pumped into the system from the Akkerkloof Dam,” said Parry. This dam is currently at 50% capacity compared with the same time last year when it was at 37%.
According to Parry, Knysna’s water system started with the Arch Dam in 1925. Since then the Glebe Dam was added in the 1960s, the first phase of the Akkerkloof Dam was completed in the 1980s with the second phase – including an upgrade – completed in the 1990s, and then another upgrade in 2012. The entire water works was upgraded in 2007.
“With the combining of smaller, individual submunicipalities a few years ago, even more pressure was put onto the system. Not all these water systems were on the same level or of the same quality, therefore a lot of upgrades had to be done to bring them all up to standard,” said Parry.
“We are behind with the upgrading and replacement of the existing pipeline which has been around since the 1960s, but funding has been the main issue here,” said Parry.
Planning for the upgrading of the entire Knysna pipeline has already started a while ago, according to Parry. “A record of decision has already been acquired for this upgrade and the nature conservation process has already started. The entire project will cost R70-million, and so far we have received R22-million in municipal infrastructure grant (MIG) funding.
The upgrade will also serve a purpose in future when a new dam is built, so saying that the municipality has done no planning is incorrect. Planning started in 2000, with the raising of funds being the most difficult aspect,” said Parry.
Where our water comes from
- About 7.68Ml of water comes from the Knysna River per day.
- About 2.5Ml comes from the Gouna River per day.
- Boreholes around Knysna supply about 1.28Ml of water per day.
- The Glebe Dam can hold about 150Ml at full capacity.
- The Akkerkloof Dam can hold about 860Ml of water at full capacity.
- Rainfall, because it is seasonal, is not included in daily calculations and therefore does not have much of an impact on the system, said Parry.
Going back to 1977, figures shows that Knysna had an annual water demand of less than 1- million cubic metres. By 2003 it had grown to 3-million cubic metres. Currently the town needs 3.57-million cubic metres, of which the system can only supply 3.03-million cubic metres per annum.
“By incorporating the desalination scheme, various boreholes and springs, the system can be temporarily boosted to provide 4.15-million cubic metres a year,” added Parry.
The problems being experienced with the system at the moment, he said, is the lack of funding to maintain and operate this expensive system, as well as operational constraints.
“Because the demand is so extreme – with the continuous growth of the town – it keeps putting pressure on the current system. We continuously plan for this, but because different departments are involved with, for example building new housing, funding is divided and not all aspects fall into place at the same time.
There is a very fine balance among all the aspects involved that needs to be reached, from residential areas to businesses to tourism,” said Parry.
Desalination and reverse osmosis plants
“Residents must remember that the desalination and reverse osmosis plants were initially built as a risk mitigation and emergency measure. The water they will supply is not added to the current water supply,” said Parry, adding that their use would alleviate only small parts of the Greater Knysna.
Currently, only one of the two units at the desalination plant is in working order. When it is in full operation it will be able to supply Sedgefield with up to 750kl of water. The desalination plant draws water directly from the ocean.
The reverse osmosis plant in Knysna, which draws water from boreholes, is currently not in working order.
According to Parry there are some cracks in its filters and maintenance needs to be done before it is operational.
Parry mentioned the following prevention measures that will be, or have already been put in place to address overconsumption: “If usage continues to exceed the target, we will start identifying the top 20 users in each sector (residential, business, etc) and initiate talks with them to decrease their usage.
There is currently also two maintenance teams available after hours to address pipe bursts, and council has already decided to install water conservation devices on the pipelines that feed townships and informal settlements.”
The Knysna municipality updates residents of Greater Knysna on water usage and dam levels on a weekly basis on their website. For the week of February 27 to March 5 the target for daily water use for Knysna was 8Ml, with the actual usage at 11.79Ml. Sedgefield, with a target of 1.9Ml/day, had an actual daily usage of 2.02Ml.
According to the municipality’s website the Akkerkloof Dam was at 50% capacity, with only 5mm of rainfall received in Sedgefield.
As water restrictions are still in place, KPH will keep a close eye on the situation to update residents on new information gathered, or when the situation changes.
ARTICLE: STEFAN GOOSEN, KNYSNA-PLETT HERALD JOURNALIST
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