Water Resource Situation as at 7th December 2016

Issued by Shami Harichunder, Corporate Stakeholder Manager, Umgeni Water

Umgeni Water’s largest system which supplies water to an estimated 4 million consumers in uMgungundlovu District, Pietermaritzburg, much of Durban and part of Harry Gwala District remains under stress as the drought continues its firm grip on KwaZulu-Natal.

The system in question, Mgeni, comprises, in the upper part, Mearns Weir, Spring Grove Dam and Midmar Dam. The lower part of this system comprises Albert Falls Dam, Nagle Dam and Inanda Dam. The levels of four of these dams are lower than they had been a year ago while the levels of the remaining two are marginally higher than they had been a year ago. The levels of these dams as at 7th December 2016 are shown on the left while their levels a year ago are in brackets:

  • 53% Midmar: (50%)
  • 63% Mearns Weir: (62%)
  • 46% Spring Grove: (80%)
  • 65% Nagle: (67%)
  • 27% Albert Falls: (42%)
  • 66% Inanda: (82%)

Water scarcity in Mgeni system has been as a result of a prolonged period of below-average rainfall in the major catchments, culminating in the major dams, Midmar and Albert Falls, being a low levels. Midmar Dam has been stabilised in mid-50% as a result of transfer of water into it from Spring Grove Dam and some rainfall. Of great concern to Umgeni Water is the level of Albert Falls Dam, the largest of the dams that are either owned or managed by Umgeni Water. Water is normally transferred into Albert Falls from Midmar, but application of this rule had to be stopped because of inadequate water in Midmar.

Declining water levels in Mgeni system has forced Umgeni Water to reduce by 15% production of potable water at Midmar Water Works, DV Harris Water Works, Durban Heights Water Works and Wiggins Water Works and to also implement water rationing. Mandatory water restrictions of 15% have also been implemented in uMgungundlovu, Pietermaritzburg and greater Durban.

Umgeni Water has issued a reminder to all consumers, including arriving holidaymakers, that water restrictions still remain in place in all of uMgungundlovu, Pietermaritzburg and in about 80% of Durban. An appeal has also been made to consumers to use water sparingly.

Water restrictions were implemented as a strategy to prevent possible failure of Midmar and Albert Falls dams. Failure of these dams would have had dire consequences for the economies of Pietermaritzburg and Durban. Failure occurs when a dam dries up, leaving only silt in it.

In October and November 2016 and estimated 1 000mm rainfall was received in Mgeni system. This is on par with the average for this period. However, rainfall received thus far in 2016 and in 2015 and part of 2014 remains in a deficit state which means that the amount received is far less than the average annual rainfall. In order for the situation to return to a state of normality and dams to begin rising significantly at least two seasons of above-average rainfall are required. Midmar and Albert Falls dams will have to reach levels of 70% each before the resource in them could be considered to be adequate and able to meet the full needs of uMgungundlovu District Municipality, Msunduzi Local Municipality and eThekwini Metro.

Forecasts by South African Weather Service and the Council for Scientific and Industrial Research suggest that if above-average rainfall is received, this is only likely to occur in the first quarter of 2017. This means that the amount of water available in Mgeni system will have to last until the next rains.

It is, therefore, imperative that disciplined use of water and strict adherence to the restrictions continue. In Ixopo, Harry Gwala District, 30% water restrictions remain in place. An emergency scheme has been implemented to transfer water into Ixopo dam. Similarly, 30% water restrictions have been implemented at Maphumulo, iLembe District, as a result of the town’s main source of raw water supply, Imvutshane River, having dried up. Water is being transferred from Hlimbithwa River into Imvutshane River through an emergency scheme for supply to and treatment at Maphumulo Water Treatment Plant.

In the remaining two systems of Umgeni Water, Middle South Coast and Hazelmere, all water restrictions have been removed following good rains in August, September, October and November 2016. With an influx of holidaymakers imminent, Ugu District Municipality’s water demand for supply to Umzinto, Scottburgh, Pennington, Kelso and surrounds is expected to increase by between 20% and 30% per day until the end of the summer recess.

The Mzinto system (Middle South Coast) has recovered significantly from a year ago and, as at 7nd December 2016, the three dams there Umzinto, EJ Smith and Nungwane were overflowing. A year ago to the day, the levels of these dams were 35%, 60% and 26% respectively and mandatory water restrictions were implemented to curb demand and consumption.

A readiness plan has been implemented by Umgeni Water in the South Coast to handle potential increase in demand during the coming holidays. This plan includes having staff, including plant operators, on stand-by; maintenance staff being on stand-by; identifying potential snags and problems that could interrupt production of potable water and fixing them, and providing contact details of key technical staff to Ugu District Municipality.

In Hazelmere system, potable water production at Hazelmere Water Treatment Plant has returned to pre-drought levels, meaning there is adequate water to meet eThekwini Metro’s full demand for supply to Verulam, Waterloo, Sea Tides and La Mercy, and iLembe DM’s requirements for supply Ballito, Umhlali and parts of Ndwedwe. Restrictions were lifted after Hazelmere Dam began filling rapidly because of good rainfall. The dam is currently at 68%, an increase of 42% from November 2015. From mid-2014 to June 2016 the supply area of Hazelmere Dam was in a state of drought which necessitated the introduction of 40% water restrictions.