CHAPTER 4 RESULTS AND DISCUSSION
4.3 Results from questionnaire (quantitative and qualitative) analysis
4.3.2 Section B: Background on irrigation practices
4.3.2.1 Water for irrigation purposes
98 4.3.1.3 Agricultural sector(s) (QA4F)
Participants in the Farmers group were asked to indicate in which agricultural sector(s) they fall (QA4F). The responses indicated that the dominant crop type (73%) was grapes (table and wine grapes) with fruit (citrus, apples, peaches etc.) and grain (including animal feed and canola) each 7% with mixed farming selected by 20% of participants. Mixed farming included dairies and other minor crops.
99
Breede River sections was important as these sections were highlighted as areas of concern regarding water quality as highlighted earlier in section 4.2.
Figure 4-21a: Distribution of participants of the Farmers group throughout the BGWMA relevant to the study (QB1F).
Figure 4-21b: Distribution of participants of the Expert group throughout the BGWMA relevant to the study (QB1E).
Farmers were asked if they make use of any form of irrigation on the farm (QB3F) to be able to screen out those where no irrigation from the surface water in the BGWMA occurred. Of the 15
0%
5%
10%
15%
20%
25%
30%
35%
40%
45%
50%
A. Upper Breede River section
B. Middle Breede River section
C. Lower Breede River section
% of participants
section of Breede-Gouritz Catchment Management Area
Breede-Gouritz Catchment Management Area (Farmers)
0%
10%
20%
30%
40%
50%
60%
70%
A. Upper Breede River section
B. Middle Breede River section
C. Lower Breede River section
% of participants
section of Breede-Gouritz Catchment Management Area
Breede-Gouritz Catchment Management Area
(Experts)
100
Farmers interviewed only one (1) did not make use of irrigation but mainly relies on rainfall with augmentation from ground water as emergency supply during extended droughts. It was important to also include the views of this Farmer as a control in the sample of irrigation Farmers.
Farmers and Experts were asked to indicate the main source of water for irrigation purposes (QB2E/QB2F). The majority of Farmers (14) (93%) indicated that they make use of surface water as main source of water with rainfall identified as the main secondary source of water (9) (60%) with only (5) 33% of Farmers indicating that they make use of ground water as a secondary source of water (Figure 4-22). The Experts group, however, identified ground water (8) (62%) and rainfall (5) (39%) as the most dominant secondary sources. Ground water is more often utilised in the Upper Breede River section as a secondary source of water (75%) compared to the Middle Breede River section (29%) and Lower Breede River section (0%) (Figure 4-23).
Figure 4-22: The distribution of the main and secondary water sources identified by Farmers (QB2F).
This corresponds to findings by previous studies which showed that ground water originating from the TMG fractured aquifer in the mountainous areas (Upper Breede River section) were good quality, low salinity water whereas the ground water in the valley bottoms (Upper and Middle Breede River sections) had the highest salinity, attributed to the argillaceous (shale-rich) host rock of the Bokkeveld Group (Murray, Biesenbach and Badenhorst Inc. 1989; Kirchner et al. 1997;
DWAF, 2003).
93%
0% 7%
0%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
A. Surface water B. Ground water C. Rainfall D. Municipal
% participants
Source of water
Main source of water (Farmers)
101
Figure 4-23: The distribution of the main and secondary water sources identified by Experts (QB2E).
These studies also confirm that, based on the high salinity levels, ground water was not an important source of water for irrigation purposes in the BGWMA. Farmers were asked to select the main irrigation water distribution infrastructure from which they receive water (QB3E/QB4F).
The majority of Farmers indicated that they received water from the Breede River (40%) or the tributaries thereof (13%) compared to 27% of Farmers indicating that they receive water for irrigation mainly from the irrigation canals as the primary source (Figure 4-24).
Figure 4-24: Distribution of main water source used in irrigation indicated by Farmers (QB4F).
100%
0% 0% 0%
0%
62%
46%
0%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
A. Surface water B. Ground water C. Rainfall D. Municipal
% participants
Sources
Sources of water (Experts)
Main source of water Secondary source of water
40%
13%
27%
0%
0%
0%
13%
0% 5% 10% 15% 20% 25% 30% 35% 40% 45%
A. Directly from Breede River B. Directly from tributaries C. Irrigation canal D. Irrigation dam E. Ground water F. Rain fed irrigation dams G. Other
% participants
Water source
Main irrigation water source (Farmers)
102
The second most dominant source of irrigation water were indicated as either irrigation canals or irrigation dams with only 14% of Farmers indicating that the second most dominant source were ground water. Experts agreed with these findings that indicate irrigation directly from the Breede River (69%) is the main source of irrigation water distribution with the tributaries the second most dominant source of irrigation purposed water (62%).
The main irrigation source changes as one moves from the Upper to the Lower Breede River as indicated in Figure 4-25. In the Upper Breede River section the main source is spread evenly between the surface streams (Breede River and tributaries) and irrigation canals. The majority of Farmers (57%) in the Middle Breede River section selected irrigation directly from Breede River and irrigation canals (43%) as the main irrigation sources and 57% as the second most dominant source (Figure 4-25). The Breede River is again indicated as the main source (67%) in the Lower Breede River section. These findings are in agreement with previous studies which showed that the Middle Breede River section has a larger network of the irrigation infrastructure compared to the other section (DWAF, 2003a).
(a)
0%
20%
40%
60%
80%
100%
A. Directly from Breede
River
B. Directly from tributaries
C. Irrigation canal
D. Irrigation dam
E. Ground water
F. Rain fed irrigation
dams
G. Other
Upper Breede River section
Dominant (1) Moderately high dominance (2 &3) Neutral dominance (4) Moderately low dominance (5 &6) Least dominant (7)
103 (b)
(c)
Figure 4-25: Distribution of main irrigation source across categories per Breede River section (QB3E/QB4F).
The intention behind the inclusion of this detail was to determine from which source the irrigation water was received to be able to determine which irrigation water distribution infrastructure was the main conveyor of the potentially contaminated water identified earlier in section 4.2; to be linked with section 4.3.4 and 4.3.5. The level of knowledge of the Farmers and Experts related to the water quality in the different sections of the BGWMA will also be important in the evaluation
0%
20%
40%
60%
80%
100%
A. Directly from Breede
River
B. Directly from tributaries
C. Irrigation canal
D. Irrigation dam
E. Ground water
F. Rain fed irrigation
dams
G. Other
Middle Breede River section
Dominant (1) Moderately high dominance (2 &3) Neutral dominance (4) Moderately low dominance (5 &6) Least dominant (7)
0%
20%
40%
60%
80%
100%
A. Directly from Breede
River
B. Directly from tributaries
C. Irrigation canal
D. Irrigation dam
E. Ground water
F. Rain fed irrigation
dams
G. Other
Lower Breede River section
Dominant (1) Moderately high dominance (2 &3) Neutral dominance (4) Moderately low dominance (5 &6) Least dominant (7)
104
of key drivers of and risks posed by the water quality and will be important in the discussions in sections 4.3.4 and 4.3.5.