Being a new parent is a rude awakening. Being a new parent for the second time around leaves one feeling like a stream in a Karoo drought. As new fathers, Jason, a mate of mine, and I hightailed it one evening to a local hang-out den for rain. After several minutes of preferred silence, and sipping gummy berry juice, we both observed that, of the 150 or so patrons, most were Mandela's children dressed to the nines - middle upper-class young professionals. Even to the untrained eye, ours was the solitary conspicuous multicultural table. Jason is of European descent. Every other table comprised single race groups - there were several Black tables, White tables, and a Coloured table, spiced with a few Indian tables.
The Usutu Water Scheme in the Mpumalanga Province of South Africa supplies raw water to various coal-fired power stations and towns. The DN1300 mm, pre-stressed concrete non-cylinder pipe (PCP) between the Rietspruit and Davel Reservoirs (36.5 km), and between the Davel and Kriel Reservoirs (54.4 km) was completed in the late 1970s and forms a strategic link in the scheme.
Floods in South Africa in the 2013/2014 rainy season caused at least 50 fatalities and affected about 50 000 people. In addition to loss of life and injuries, people were evacuated from their homes, and/or their homes were damaged or destroyed. An indication of the damage is depicted in the map below (based on articles on floodlist.com).
Th e National Water Resources Strategy (2013) states: "For water to play an optimal role in poverty eradication, the reduction of inequality, inclusive growth and development, and building a just and equitable society, water resources planning must be integrated into national, provincial and local planning, and must be addressed in all growth and development strategies."
As a result of a collective effort from public and private entities, about 6.8 million m³ of water, and in the order of R37 million was saved in Emfuleni - one of South Africa's largest local municipalities - by implementing a range of comprehensive water-loss reduction measures. This article outlines how this was possible and what needs to be considered when implementing similar approaches elsewhere.
On-site water conservation and leak repair by municipalities in private properties is one of the strategies that can be employed to reduce water consumption. Lugoma et al (2012) highlighted some studies that have been done on on-site leakage. They also highlighted some South African projects that realised water consumption reductions of between 20% and 38% due to on-site leak repair. Even though on-site water conservation and leak repair have been shown to be successful, and the benefits can be achieved in a relatively short period, it is not being done by most municipalities, because municipal policies and/or bylaws do not allow leaks to be repaired by municipal personnel on private properties (Wegelin et al 2009).
The City of Tshwane (CoT) Water Resources Master Plan concerns the possible upgrading or extension of the CoT's own water resources, with a view to reducing the dependence on imports from the Vaal River basin (via Rand Water). It also concerns the Olifants River basin and the Crocodile River basin, which receive significant sewer return flows from the CoT, influencing the yields of the local water resources and water allocations to downstream users.
On 31 March 2015 the Minister of Water and Sanitation, Nomvula Mokonyane, unveiled Bloemwater's conduit hydropower facility at the Brandkop Reservoir, and celebrated the major scientific and engineering achievements made by the team of researchers.
The abstraction of water at mines is an ongoing challenge requiring innovative solutions in order to have little or no impact on mining production. Pump stations often need to be demolished and rebuilt as mining activities move around. Construction on mining property is, however, becoming more and more challenging due to regulations. Contractor health and safety inductions, amongst others, have become a lengthy and expensive process which directly impacts the construction phase.
South Africa is a rapidly urbanising country with complex water management challenges, including significant resource shortages, fragmented institutional structures, as well as associated negative impacts on the quality of surface and groundwater resources. Alternative approaches to conventional water management, which aim to facilitate a change from 'water-wasteful' to 'water-sensitive' environments, are required if serious economic and socio-political threats are to be averted. Water Sensitive Urban Design (WSUD) is such an approach. It reflects a paradigm shift in the way urban environments are planned and designed so that issues of water sustainability and environmental protection are paramount, together with the provision of multiple benefits and opportunities to overcome specific challenges of water management.
Aerobic granular sludge has been developed as an alternative to the activated sludge systems that are commonly applied for municipal and industrial wastewater treatment worldwide (including in South Africa). Activated sludge systems use flocculent biomass which has relatively low settleability, necessitating large secondary settling tanks and low reactor biomass concentrations (3-5 gMLSS/ℓ). In turn, activated sludge systems have a significant footprint (space requirement) and require a relatively large energy input (aeration and recycle pumping). In contrast aerobic granular sludge comprises more compact and dense bio-granules that result in improved sludge settling characteristics (up to > 10 m/h). Aerobic granular sludge is formed by applying specific process conditions that favour slow-growing organisms such as PAOs (polyphosphate accumulating organisms) and GAOs (glycogen-accumulating organisms), and suppression of the growth of flocculent biomass, together with selective wasting whereby slow-settling floc-like sludge is discharged and faster-settling biomass is retained.
The signing of the Lesotho Highlands Water Project (LHWP) Treaty between the governments of the Republic of South Africa and Lesotho on 24 October 1986 heralded the start of the largest international water project yet undertaken in southern Africa.
The Swaziland Water Services Corporation awarded Inyatsi Construction a tender to construct a Wastewater Treatment Plant and Outfall Sewer located on the outskirts of Matsapha in Swaziland. When operational, this plant had to be able to process up to 20 Mℓ of wastewater per day. Practical completion was awarded in September 2014.
The South African National Committee on Large Dams (SANCOLD) was formed in 1965 when it joined the International Commission on Large Dams (ICOLD). At that stage there were only 45 member countries in ICOLD compared to the current 97, and six African Member countries compared to the 22 at present. When joining ICOLD, the proposed National Committee must form the organisation and prepare a constitution, as well as submit a register of its large dams, generally defined as having a height of more than 15 m. The current Register of South African Large Dams is on the SANCOLD website. The original initiative to form SANCOLD was driven by the then Department of Water Affairs. It is interesting to note that the SAICE Water Engineering Division also celebrates its 50th anniversary this year. Over the years there has been close collaboration between the two bodies.
SAICE's Water Engineering Division celebrated its 50th anniversary during National Water Week on 20 March 2015. The stylish event was attended by the who's who in the industry and was held at the Johannesburg Country Club in Auckland Park.
This article is the fifth in a series on the economic pricing of services and the beneficial effect this could have on the economy and the everyday lives of people. The first four articles appeared in the October 2014, November 2014, March 2015 and April 2015 editions of Civil Engineering.
Vacuvent has recently developed a smarter, more sophisticated anti-shock orifice for air release valves. Vacuvent's new, smart anti-shock nozzle opens under pressure should a large bubble of air enter the air valve. Th is largely solves the problem of air entrapment and dynamically limits the outflow of air during all pipeline phases.