2011 update 37 year Perth dams catchment rainfall trend – nearly a Thousand GL of water wasted over 15 years by not managing catchmentsJanuary 1st, 2012 by Warwick Hughes
In 2011 the Perth region has enjoyed an above average rain year – as shown in my graphic of 37 years of Perth dams catchment region May-October rainfall.
This second graphic shows the constant decline in “catchment efficiency” CE since the late 1990′s – which was about the last time water authorities did much to control understorey regrowth in catchments which drastically cuts back inflows to streams. A calculation for each of the last 15 years – assuming that a CE of 5.6% could easily be achieved without harming wildlife values – shows that a total of 998GL has been lost from 1997-2011. I have not costed this – but the extra 66GL PA would have made it unnecessary to embrace seawater desalination in such a rush.
2010 update 36 year Perth dams catchment rainfall trend
Stunning ignorance and lies surround Perth water supply policies
2009 update – Perth dam catchments rainfall still normal, Govt building $Billion seawater desalination plant #2
There never was a rain shortage to justify seawater desalination for Perth’s water supply