Water supply situation
Lerato Maleke | Friday August 8, 2014 14:57
He however, highlighted a few which include the Lobatse dam, and the support infrastructure, which he said currently supplies 22 villages in Tswapong North; the Maun water treatment plant, which moved Maun from water supply deficit to surplus; the Malwelwe water augmentation scheme which moved Molepolole from water supply deficit to surplus; the Goodhope water supply augmentation, which he said has significantly improved water situation in Goodhope; the Middlepits cross border supply which he said has improved water supply situation in the Middlepits cluster and finally the connection of an additional borehole at Selokolela and has improved water supply situation in Kanye and Moshupa villages.
However, the minister said that the greater Gaborone area is experiencing a serious drought due to poor rains in the region over the past two to three seasons, resulting in Gaborone dam levels declining to a very critical and unprecedented low level of 10%. He said that the decline of the dam level has invariably resulted in a huge reduction in the rate of abstraction from the nominal 84 million litres a day to 48.
“Under the circumstances given the anticipated increased decline of the dam level due to the eminent summer season, which is characterized by high evaporation rates and water demand, the likehood of pump failure as increased and might result in a total dam failure” he revealed. He said that it must be noted that under normal operating conditions, with all systems available, the greater Gaborone area water supply is in surplus. He however said that following the drought situation obtaining in the area, his ministry has since imposed the more stringent level 2 water restrictions, complimented by a three-day-weekly water rationing plan, with a view to achieving a reduction in demand of 30% from the average daily demand of 125 ML/day, which is premised on a supply scenario devoid of Gaborone dam, assuming its imminent failure.
The minister said that without any significantly inflows, the Gaborone dam is anticipated to fail within the next two or three months and that this scenario calls for urgent action by the ministry and key stakeholders including the water consumers. Mokaila argued that Botswana is a scarce country and that water conservation should be Batswana’s lifestyle, adding that under the scenario of an imminent failure of the Gaborone dam even more effort towards water conservation is called for and that more of the water rationing or shedding is necessary.
Therefore he said that in the coming days, the Water Utilities would advise the nation on water restrictions and rationing measures being imposed to mitigate the situation. However, he said that over and above the water restrictions and rationing measures that have been enforced, the ministry has come up with initiatives to mitigate the situation. These include Masama wellfield development to augment the water supply for the greater Gaborone; Ramotswa wellfield refurbishment and treatment plant to augment the water supply to Ramotswa and Lobatse; construction of the North-South Carrier 2, currently construction up to Palapye is ongoing with the Palapye to Mmamashia planned for the National Development Plan 11 period and finally the refurbishment of the PS3 Pumpstation.
Mokaila said that under the current drought situation water supply augmentation through the North South Carrier (NSC), which now accounts for over 50% of the supply to the area, has become more eminent. “It follows therefore given the critically of the scheme that its availability and reliability are of the essence, this notwithstanding the NSC continues to experience consistent pipeline failures, especially at the weak 26 km upstream of Palapye”, he lamented. However, the minister said that this scenario, coupled with the likely failure of Gaborone Dam in the next two or three months has warranted the acceleration of remedial works at the 26km pipeline section, which he said basically entail the inter-connection of a more robust steel pipeline, as part of a parallel line from Moralane Pump Station to Palapye.
He said that the construction of the section is complete and that its inter-connection to the existing NSC1 pipeline requires a 21-day shutdown, which is scheduled for August 7 to 28 2014.
He said that during this time and the temporary absence of NSC water supply, the greater Gaborone area supply will be met from Gaborone, Bokaa, Molatedi, Ramotswa wellfield and Nnywane dams, with a combined supply capacity of about 103ML/day, and a deficit/shortfall of about 20MI/d. “This will warrant the intensification of the water rationing plan to reduce demand” said the minister.
Although government endeavors to develop and implement effective plans to augment water supply, Mokaila said that it must be noted that water supply sources are finite and vulnerable to drought and infrastructure related factors. Therefore the minister said that it is prudent to exercise water demand management and conservation as a more sustainable modality to manage the scarce water resource.