Water Resource Management

The National Water Resources Strategy (NWRS) presents water balances for the water management areas (WMAs).

In drier parts of Southern Africa, water reservoir releases into riverbeds often lead to significant losses of flow volumes (river losses) and result in supply shortages for downstream water users.

The DWAF Directorate: National Water Resource Planning has commissioned five studies on the Mhlathuze, Inkomati, Berg, Crocodile (West) and Olifants river systems, for the purpose of assessing the available water resources in support of the eminent process to license water use.

The WQT salinity modelling system was developed in the late 1980s for the Department of Water Affairs and Forestry and has been used successfully throughout South Africa for Total Dissolved Solids (TDS) modelling.

The purpose of this assessment was to determine general and drought curtailment rules for the major dams situated within the Great Marico River System.

Recent studies have indicated that water allocated to users in the Mhlathuze River catchment exceeds the available yield of the system.

South Africa has one of the most complicated and integrated water resource systems in the world involving numerous interlinked river systems and major interbasin transfer schemes.

Reconciling the available water resources of the Vaal River System with the future expected water requirements of the system is an essential and continuous management activity of the Department of Water Affairs and Forestry (DWAF).

In the latter part of the previous decade as well as the early part of this decade considerable time and effort have been spent developing a hydraulic model for the lower reaches of the Orange River (approximately 1 400 km from Vanderkloof Dam to the river mouth) during two Water Research Commission (WRC) managed studies.

The operating costs (in particular pumping costs) of the various water resource systems in South Africa amounts to hundreds of millions of Rands per year and much effort is invested by water resource planners to implement cost saving operating rules that do not jeopardize the long term assurance of supply.

In the context of the challenges facing water resource management in South Africa and given the status of the prevailing analysis techniques, an evaluation of constraints and opportunities are presented to serve as background for a proposed framework for future water resource analysis in the country.

The purpose of this development was to produce simplified curtailment curves that can be used to decide when and how severe curtailments need to be in periods of water shortage.

The Crocodile (West) River catchment, measuring approximately 29 300km² in extent, is a densely populated, substantially urbanised and industrialised catchment.

Understanding and managing leakage in potable water distribution systems has always posed interesting and often difficult problems to the water supply authority.

The Department of Water Affairs and Forestry (DWAF) developed the Water Situation Assessment Model (WSAM) as a macro-scale water resource planning tool.

Under natural conditions approximately 50% of all the flow in the Schoonspruit catchment, comes from the Schoonspruit Eye, emphasizing the importance of the correct simulation of the eye flows.

It is perceived that some uncertainty currently exists regarding the appropriate procedure that should be followed to lump small dams for the purpose of undertaking water resources modelling.