A closer look at Plett’s looming water crisis


There is a strong possibility that Bitou will soon experience a water crisis similar to that in places like Knysna and Cape Town - BASIL VAN ROOYEN and OLIVER RISSIK of Plettenberg Bay Community Environmental Forum report

CXPRESS readers would have learnt in last week’s issue about Knysna’s dire water situation. It raises the question though: where do we stand in Bitou? The answer makes for grim reading.
Many Bitou residents know that we are in the midst of a drought and that Phase 1 water restrictions have been introduced, but few people seem to realise the potential severity of the situation.
To understand the risks, we need some background.
Keurbooms River is the only source of water for the large Bitou municipal area. Many people wrongly believe that Roodefontein is our source of water, but it is in fact only an off-channel storage dam for water extracted from Keurbooms River - except for a small amount coming from the dam’s own limited catchment area.
Reduced rainfall and effect on dam level
The average annual rainfall for Bitou since 1997 has been 732mm per year. This year from January 1 to June 30, a total of only 98mm fell over a period of six months, contributing to the conditions that made the recent fires possible. Long-range forecasts for the latter part of the year are not encouraging.
Roodefontein’s dam level reflects the state of Bitou’s water supply. Phase 1 restrictions were triggered when the dam reached 60% capacity (as opposed to 95% in December).
Phase 2 restrictions, with more severe conditions, will be imposed when Roodefontein Dam reaches 50%.
Due to very low flow in the Keurbooms, virtually no pumping is being done from there. There is provision for Phase 3 restrictions which will only be imposed under severe conditions. All water now being used is from Roodefontein Dam itself, with a small amount coming from the desalination plant.
The desalination plant is working at full capacity of two megalitres per day (Ml/day) but will be shut down for maintenance during August. If the water crisis continues, it will be brought back into use in September.
As an interim measure, boreholes are being drilled in the Uplands area. So far three boreholes have been drilled, yielding some 5Ml/day. A fourth hole is now being drilled.
This water will be pumped directly into the main gravity pipeline to Roodefontein Dam once the boreholes have been equipped and commissioned.
A borehole has also been drilled at the Kurland Village water purification plant. This borehole has a yield of 5l/sec, which hugely alleviates the Kurland supply - it is pure water and does not need to be treated. Drilling for a second borehole is being considered.
Water usage
During normal off-season times Bitou’s water demand is about 10Ml/day. Since restrictions, the demand has dropped from 9.2 to 8.7Ml/day (June 2017) and is expected to decrease further.
During the 2016 Christmas period, at the height of the visitor influx, the daily demand went up to between 15 and 17Ml/day, peaking at 19Ml/day for a brief period.
If the drought continues, Bitou might face a water situation like that of Knysna come Christmas.
Long term
Wadrift Dam, which is to be an off-channel storage dam for Keurbooms River water in the Uplands area above Wittedrift, continues to be plagued by various problems.
This dam is crucial for Bitou’s long-term water supply and will be filled from Keurbooms River in times of high flow. Under dry conditions, like that being experienced now, filling the dam could take several years.
Currently, the deadline for completion of Wadrift Dam is 2022.