29
30
31
32
25
26
27
28
33
34
21
22
23
24
17
18
19
20
13
14
15
16
9
10
11
12
5
6
7
8
1
2
3
4
Supplementary Materials (Pfautsch et al., 2014)
Detailed description of the hydrogeological setting
The study focused on riparian E. victrix along the upper and mid-section of Weeli Wolli
Creek, 80 km northwest of Newman (Fig. 1). The lower section, a broad outwash into the
Fortescue River Plains was not part of this study. A narrow gorge in the Packsaddle Range, which is part of the Brockman Iron Formation, marks the boundary of the first and second creek sections. Here the parent rock material acts as natural dam for upstream groundwater flows, forcing them to the surface where they feed a series of perennial springs. Under natural conditions, surface flow from the spring zone continues for about 2 km before disappearing under ground, contributing to recharge of the aquifer under the mid-section.
The aquifer underneath the upper section of Weeli Wolli Creek is highly stable. Data from 13 monitoring bores (Fig. 1, manually dipped every fortnight) indicated that mean groundwater depth across these bores fluctuated 0.6 m ( SD ± 0.47) between 2000 and 2005, despite varying volumes of recharge during wet seasons. Due to local variation of bedrock material and the presence of paleo-channels, actual depth-to-groundwater at individual bores ranged from 1 to 49 m. According to data from monitoring bores, depth-to-groundwater in the midsection of the creek prior to groundwater extraction was also stable.
Abstraction of groundwater from the upper aquifer commenced early 2007. In 2010, abstraction exceeded 35 GL. During that time groundwater fell approximately 50 m at the center of the cone of depression (Fig. 1). According to interpolated data from monitoring bores, the eastern hydraulic head stabilized close to the well field causing a steep base slope
(Fig. 1 & S1). Towards the south, no geological barrier limited extension of the cone, resulting in less pronounced base slope inclination and progression of the hydraulic head further away from production bores (Fig. 1). Dewatering could potentially halt groundwater flows towards the Weeli Wolli Springs, an area of ecological and cultural significance. To prevent drying of these springs, a chain of discharge spurs was installed beyond the eastern hydraulic head. Spurs continuously discharged groundwater into the creek (9.1 GL in 2010,
2.2 GL during our study period), maintaining sub-surface flows towards the spring zone.
Additional groundwater (23 GL in 2010, 6.1 GL during our study period) was discharged below the spring zone via a gabion. Location of the spur-system and the gabion is indicated in Figure S1.

35
36
37
38
39
Table S1: Key physical properties of Eucalyptus victrix used for water use measurements.
Tree diameter 130 cm above ground (DBH) was measured 1.3 m above ground; sapwood depth ( D
S
, n = 4) and bark depth ( D
B
, n = 4) is shown for each tree with SD in parenthesis.
Sapwood area of the outer sapwood band ( A
Sob
, 0-14 mm D
S
) is also given.
Site name Tree Height DBH D
B
(m) (mm) (mm)
D
S
(mm)
A
Sob
(m
2
)
Control
29
1
2
Drawdown 3
4
5
1
2
3
4
5
Control
6
Surplus
1
2
3
4
5
1
2
3
4
5
28.7
24.5
18.1
18.5
12.2
12.3
11.0
20.6
23.4
21.1
20.5
13.3
12.5
641
262
18.0 370 19.0 (0.4) 25.9 (4.6) 0.0130
19.5 301 18.3 (1.1) 31.2 (0.3) 0.0105
252
509
284
317
358
398
744
372
355
275
282
16.8 (0.9)
12.5 (0.3)
13.5 (0.5)
16.8 (1.3)
18.5 (1.7)
27.0 (0.7)
22.3 (1.3)
14.5 (1.0)
20.4 (0.9)
17.8 (1.0)
19.3 (0.3)
11.8 (0.9)
13.3 (1.6)
22.8 (2.1)
17.7 (0.9)
17.0 (1.7)
16.0 (1.5)
18.5 (1.7)
24.4 (3.1)
30.6 (0.6)
21.5 (3.1)
18.0 (1.1)
22.1 (2.9)
20.2 (1.0)
20.4 (5.5)
15.6 (0.4)
0.0260
0.0116
0.0124
0.0230
0.0145
0.0103
0.0123
0.0143
0.0345
0.0130
0.0124
0.0092
0.0124
17.3 452 17.0 (1.3) 12.2 (0.7) 0.0155
13.4 257 15.1 (1.2) 16.8 (0.2) 0.0112
12.4 409 15.8 (0.7) 9.9 (1.7) 0.0097
9.6 213 12.5 (0.4) 16.9 (0.1) 0.0092
15.3 413 14.0 (0.6) 12.5 (1.3) 0.0132

40
41
42
43
44
45
46
47
48
49
Figure S1: Schematic cross section for position of historic (dashed line, Jan 2007) and modified (solid line, Nov 2010) groundwater table from the dewatering bore field towards the spring zone of Weeli Wolli Creek, including location of two research sites (Drawdown,
Contol
6
). Elevation of groundwater is given in meters Australian Height Datum (m AHD).
Discharge spurs are represented as single-crossed dots. Double-crossed dot shows position a large permanent discharge outlet (gabion).

50
51
52
53
54
55
Figure S2: Relation between tree diameter (DBH) and sap velocity ( J
S
) of individual
Eucalyptus victrix trees (n = 5 site
-1
). Data was averaged for the period of 1 Sep-30 Nov 2010 and represents J
S
in the outer sapwood band (2-12 mm). Error bars show SD .

56
57
58
Figure S3: Control
29
site, Weeli Wolli Creek, October 2010.

59
60
61
Figure S4: Surplus site, Weeli Wolli Creek, September 2010.

62
63
64
65
66
67
Figure S5: Drawdown site. Weeli Wolli Creek, December 2010.