Perth media runs this story – Utility pleads for more water
I have written on this subject for more than a decade – here are just two landmark examples.
[A] There never was a rain shortage to justify seawater desalination for Perth’s water supply – Dec 2007 download my 200KB 3 page pdf “Perth water supply catchments rain report Nov 07” Still covers main issues.
[B] Ongoing decline in efficiency of Perth Dam catchments – reply from WA Minister – May 2013 – Read what I wrote to Minister Marmion and his reply – he could not contradict my point that catchment management would increase runoff to dams.
Updating to 2015 rainfall the 5 year average rain 2011-2014 is about 850mm. Below is the latest chart of Perth catchments rainfall May-Oct rainfall 1980-2015 which shows CE (Catchment Efficiency) plunging to under 2%.
What the West Australian Government (and Labor Opposition) should be doing in respect of Perth water supply policy.
1. Over-ride Green objections and manage catchments as they were in the mid 1990’s thus increasing dam inflows by an amount of water about equal to production from two desalination factories (=90 GL Per year). See graphic of declining catchment yields above. Thinning of catchment bush can be done by experts with negligible adverse effects on wildlife values. Download 1 page pdf with chart showing results of thinning the Higgins catchment near Dwellingup – from 2005 Water Corporation report.
2. Cut the Gnangara pines forthwith – the value of the trees is way less than the value of the water they are suppressing. Sell the lumber and use the land for well planned urban areas – make a huge profit from well planned new suburbs and increase underground water pumping potential by about 100 GL per year, (UWA figures from 2002). Let both mounds recover over the decades ahead. GoogleEarth images show that between 2004 and 2015 significant areas of the pines have been cleared – that will assist recharge of the Gnangara mound underground water.
3. Abandon the risky plans to pump treated waste water into your precious shallow aquifers.
4. Take on board the Agritech proposal to desalinate brackish Wellington dam water but examine augmenting it to 100 GL per year by adding similar brackish water from the Murray or Avon where hundreds of GL flow to the sea every year.
5. After seeing the benefits from 1, 2, 3 & 4 above, progressively mothball both seawater desalination factories and save taxpayers mega $’s’.
6. Engage an expert US group to trial cloud seeding for a few run-off seasons – the cost is low compared to the large value of any incremental water in dams.
7. Stop lying to the public about rainfall – let the slogan “Our drying climate”pass into history where it belongs. Instruct Water Corporation to quote catchments rainfall on their www pages and NOT Perth rainfall which does not run into dams.
8. Instruct Water Corporation to get on with their job of harvesting available falling-from-the-sky-free natural water at the lowest cost possible for the benefit of the Perth and WA public.
9. If CE (Catchment Efficiency) was increased to 5.6% – hypothetically the 19 years 1997 to 2015 would have produced an extra 64GL each year on average – taking out the 4 poor years, 2001-2006-2010-2015.
If you take the last group of good years 2011-2014 incl. the loss is worse and 116GL PA is being lost. Now what is the value of this lost water? Is it near a $Billion PA?