RESEARCH ADVANCES IN IRRIGATION METHODS FOR EFFICIENT WATER APPLICATION: SOUTH AFRICA - Management, Performance, and Applications of Micro Irrigation Systems - page 52

TABLE 2 Irrigation schemes where fieldwork took place and system components were
assessed [11].

Irrigation
system (ap-
plication)

Irrigation
management
(Soil storage)

Irrigation
scheme

Bulk con-
veyance

On-scheme
distribution

On-scheme
return flow

Breede River X X X X

Dzindi X X

Gamtoos X X X

Hartbeespoort X X

Hex River X

KZN scheme X X X X

Loskop X X

Nkwalini X X

ORWUA X X X X X

Steenkoppies X

Vaalharts X X X

Worcester East X

Acceptable ranges need to be set, and agreement obtained with the Department of
Water Affairs (DWA) as to where in the system provision should be made to cover
losses. The fieldwork undertaken in the course of the WRC project, 'Water Use Ef-
ficiency from Dam Wall Release to Root Zone Application' [11], comprised various
approaches and strategies applied at each of the irrigation schemes that were investi-
gated (Table 2) aimed at quantifying some of the water-use components mentioned.
As the application of water-balance approach was an outcome of the research rather
than anticipated solution at the outset, the fieldwork was not initially designed to pro-
duce results to which the water- balance approach could be readily applied. However,
at many of the schemes where fieldwork was undertaken, at least some of the system
components could be assessed using the water- balance approach. The research activi-
ties undertaken and the outcomes implemented were done in four phases:
1.

Baseline study phase: The various performance indicators previously avail-
able were reviewed, and irrigation systems evaluated to obtain information
on the current status of irrigation schemes and systems. The outcome of this
phase was a decision to introduce the water-balance approach in which the
frame- work components have to be defined and quantified for the boundary
conditions selected, using standardized measurements rather than the perfor-
mance-indicator approach.

Assessment phase: During this phase, existing best management practices
were used to assess the current status of irrigation schemes and systems and
to identify which components of the water- balance framework improvements

2.