Salinity situation statement Tweed River and Gnowergerup Brook

Water Resource Technical Series Salinity situation statement: Tweed River and Gnowergerup Brook WRT 41
Strategic trees and perennials to 5m rooting depth
Scenario 12
Entire area modelled
(Tweed/
Gnowergerup+ area
outside)
Kingston
Rylington
Scotts Brook
Kenninup
South Kulikup
Dwalganup Brook
Mayanup
Gnowergerup Brook
Tweed River
Area (km 2 ) 236 377 148 108 91 37 101 75 53 661
Lake area (km 2 ) 0 0 0 0 0 0 0 0 0 0
Total 2007 native forest (km 2 ) 139 112 36 51 22 5 49 48 39 263
Total 2007 native forest (%) 59 30 24 48 24 14 48 64 74 40
Total 2007 trees (km 2 ) 32 180 92 32 36 32 21 0 0 212
Total 2007 trees (%) 14 48 62 30 39 86 21 0 0 32
Total 2007 cleared area (km 2 ) 0 0 0 0 0 0 0 0 0 0
Total 2007 cleared area (%) 0 0 0 0 0 0 0 0 0 0
Total 2007 perennial pasture (km 2 ) 64 85 21 24 33 0 31 27 14 186
Total 2007 perennial pasture (%) 27 23 14 22 37 0 31 36 26 28
Average for 2030 a
Annual rainfall (mm) 590 551 551 580 548 521 576 621 568 568
Streamflow (GL) 2.13 3.83 1.71 0.63 0.92 0.22 1.07 1.00 0.51 6.73
Runoff (mm) 9.05 10.41 11.56 5.83 10.06 5.89 10.62 13.30 9.58 10.18
Salt load (kt) 1.24 3.71 1.47 0.15 1.32 0.10 0.79 0.69 0.39 6.23
Salinity (mg/L) 580 968 859 381 1434 473 736 693 778 926
Groundwater discharge to stream zone 0.39 0.80 0.81 0.00 0.15 1.34 0.71 0.81 0.60 0.79
Baseflow (mm) 1.42 0.35 0.36 1.71 0.52 0.89 0.11 1.99 0.00 1.20
Average for 2060 b
Annual rainfall (mm) 590 551 551 580 548 521 576 621 568 568
Streamflow (GL) 2.03 3.47 1.60 0.65 0.80 0.20 0.96 0.92 0.46 6.12
Runoff (mm) 8.60 9.41 10.81 6.05 8.76 5.34 9.52 12.19 8.71 9.26
Salt load (kt) 0.92 2.03 0.77 0.23 0.65 0.08 0.53 0.47 0.22 3.35
Average annual salinity (mg/L) 456 585 484 432 812 425 548 518 486 546
Groundwater discharge to stream zone 0.20 0.34 0.35 0.00 0.00 0.53 0.44 0.48 0.21 0.34
Baseflow (mm) 0.00 0.22 0.21 -1.13 0.00 0.37 0.10 1.62 0.00 0.42
Department of Water 77
a annual mean for the period 2025 – 2035
b annual mean for the period 2055 – 2065