After heavy rain in September, which resulted in the Kouga Dam overflowing for the first time in eight years, on October 4 the Department of Water and Sanitation announced water restrictions on the Kouga-Loerie Sub-System had been lifted.
Water restrictions on the Groendal Sub-System in the Nelson Mandela Bay Municipality have also been lifted.
Rienette Colesky, CEO of Gamtoos Irrigation Board, said that each year an evaluation is completed by an independent modeller who is contracted by the Department of Water and Sanitation.
As part of the evaluation process, she said that the modeller looks at the demand for water, the availability, and how to meet that demand to determine the water restrictions imposed on the Algoa Water Supply System.
Colesky said that the first restriction of 60 percent was imposed on the Kouga Dam in 2017, when the dam was at 18.65 percent on June 31, 2017.
She said that since then the restrictions have remained in place with the percentage of restrictions fluctuating each year.
Fortunately, after heavy rain during the month of September, the Kouga Dam rose rapidly with the dam level rising from 62 percent on September 26, to overflowing just three days later, on September 29.
As a result of the increase in dam levels, the Department of Water and Sanitation have lifted the water restrictions on the Kouga-Loerie Sub-System and Groendal Sub-System, which have both exceeded 100 percent.
Wisane Mavasa, the spokesperson for the Department of Water and Sanitation, said that the water restriction on these two sub-systems was lifted due to improved storage levels in these dams, up until the next decision date in November.
She further said that the recent rainfall had brought significant relief from the protracted period of drought experienced in the Algoa Bay region, with a significant recovery in dam levels to the extent that the Kouga Dam has recorded its first overflow since 2015.
“This catchment is of strategic importance to the western parts of Nelson Mandela Bay Metro, Kouga Local Municipality, as well as the agricultural sector in the Gamtoos Valley,” said Mavasa.
She said that on May 15 the Algoa Water Supply System recorded a combined storage level of only 13.3 percent, with the Kouga Dam at 14.57 percent.
As of October 11, Colesky said that there were 33 380 litres per second of water measured flow ing over the Kouga Dam wall, 14 460 litres per second over the Stuur manskraal measuring weir, and 21 35 0 litres per second flowing in the Groot River.
The current dam level is 101.25 percent.
She said that as per the department’s policy, the dam level will be reviewed on November 1, but looking at the volume of water within the Kouga Dam and the total balance of the Algoa Water Supply System, which is currently more than 70 percent, it would not make sense to impose restrictions at this time.
“We do not expect any restrictions on the Kouga Dam at this time,” said Colesky.
Even though the dam is currently full, with the restrictions being lifted, she said that they do expect the dam levels to drop.
“The water in the dam is allocated to catalyse economic growth for the Metro and for agricultural use. For this reason, the dam level will drop,” said Colesky.
Colesky said that the main problem is that the water users in the Metro have allegedly not abided by the previous restrictions.
“The Metro did not abide by any of the water restrictions imposed on the dams over the last few years which is problematic, because how do you preserve a water source if your water users do not adhere to restrictions,” said Colesky.
Thankfully, she said the agricultural users have always abided by the water restrictions regardless of how difficult it has been.
“Water is survival for the agriculture user. If they do not have water, they cannot produce and farm,” said Colesky.
“The agriculture sector has a lower assurance of supply and that is why it is critical if their water is cut.”
Due to low water balances on the Western side, which include the Kouga, Churchill, and Impofu dams, and the alleged mismanagement of water by the metro, Colesky said that the assumption was that agricultural users had received lower water allocations to “bail out the Metro”.
Despite the lifting of water restrictions, Mavasa said that the department’s Water Resource Management Planning processes are based on hydrological trends; hence there will be continuous monitoring of the accumulation of rainfall-generated run-off throughout the remainder of the hydrological year (period of monitoring) in this catchment.
She further said that restrictions in the Kromme Sub-System, comprising Churchill and Impofu dams and upstream catchment, remain in place until the next decision date in November.
Mavasa said that climate experts have warned that there are indicators of a strong El Niño developing which could coincide with warmer temperatures and lower rainfall across South Africa (CSIR, 2023).
“The full impact of the anticipated El Niño effect is not known; hence the department’s hesitancy to confidently declare that the protracted drought period has ended. The analysis over a longer period will provide for a more accurate climate and hydrological trend. This analysis will enable a decision to be made in November regarding the annual restrictions to be imposed on the region,” said Mavasa.
She said that in the meantime, the hydrological recovery of the Algoa Water Supply System has allowed the department to favourably consider the upliftment of the restrictions for the area.
“This relaxation of water use will contribute to the economic recovery in the domestic, agricultural, and industrial sectors in the area,” said Mavasa.
As of October 10, according to the Nelson Mandela Bay Municipal ity, the dam levels for the re maining dams are as follows, Church ill – 100 percent, Impofu – 29.37 percent, Loerie – 100 percent, and Groendal – 100 percent.
