Salinity situation statement Tweed River and Gnowergerup Brook

Water Resource Technical Series Salinity situation statement: Tweed River and Gnowergerup Brook WRT 41
Base case - 2007 land use
Scenario 1
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 ) 0 0 0 0 0 0 0 0 0 0
Total 2007 trees (%) 0 0 0 0 0 0 0 0 0 0
Total 2007 cleared area (km 2 ) 97 265 112 57 69 32 52 27 14 398
Total 2007 cleared area (%) 41 70 76 52 76 86 52 36 26 60
Total 2007 perennial pasture (km 2 ) 0 0 0 0 0 0 0 0 0 0
Total 2007 perennial pasture (%) 0 0 0 0 0 0 0 0 0 0
Average for 2030 a
Annual rainfall (mm) 590 551 551 580 548 521 576 621 568 568
Streamflow (GL) 5.17 14.38 7.00 2.37 3.43 1.51 2.93 1.92 0.88 21.86
Runoff (mm) 21.92 39.07 47.31 22.03 37.60 41.26 29.00 25.54 16.57 33.07
Salt load (kt) 16.28 66.68 32.47 9.47 16.64 9.38 10.42 5.13 1.68 88.98
Salinity (mg/L) 3150 4636 4638 3987 4853 6197 3561 2675 1922 4071
Groundwater discharge to stream zone 4.99 14.58 14.44 6.27 16.60 12.40 6.83 5.08 2.25 9.15
Baseflow (mm) 4.27 2.09 2.07 7.85 0.29 3.73 0.17 2.15 0.00 2.32
Average for 2060 b
Annual rainfall (mm) 590 551 551 580 548 521 576 621 568 568
Streamflow (GL) 5.03 13.95 6.90 2.37 3.30 1.46 2.79 1.83 0.83 21.27
Runoff (mm) 21.33 37.89 46.61 22.00 36.16 39.75 27.63 24.32 15.72 32.18
Salt load (kt) 15.14 64.35 31.38 8.71 15.84 9.16 10.13 4.79 1.64 85.63
Average annual salinity (mg/L) 3011 4613 4549 3672 4803 6275 3632 2624 1977 4026
Groundwater discharge to stream zone 4.71 14.29 14.16 5.80 16.45 12.15 6.88 4.89 2.23 8.94
Baseflow (mm) 4.28 2.09 2.07 7.88 0.29 3.69 0.18 2.13 0.00 2.32
Department of Water 67
a annual mean for the period 2025 – 2035
b annual mean for the period 2055 – 2065