Water-The Third Rail Part XXIII

Are the political leaders in the city of Perth, Australia smarter than the
political leadership in San Diego? Likely not, but comparing how Perth has
managed their water issues compared to San Diego, it appears to be a matter
of political will and backbone.

The City of Perth, in Western Australia is on the Indian Ocean with a
population about two thirds that of San Diego, consuming about half of the
water used by San Diego County residents. The mean temperatures are a
maximum of 76F in the summer (our winter) and 55F in the winter (our
summer). Perth came in ninth in the Economist Intelligence Unit list in
August 2012 of the world’s most livable cities. San Diego did not make the
list.

In years past, Perth has relied on rainfall and storage to supply the city’s
annual use of 243,019 acre-feet of water (San Diego’s uses 500,000
acre-feet). Did they build more storage to catch more of an average annual
rainfall of thirty-three inches? That’s what San Diego County water leaders
are doing.more storage. No, as the climatic conditions changed in Western
Australia, the leadership began building the most energy efficient
desalination plants in the world. They may have considered potable
recycling, but for reasons unknown chose to go the desal route.

In 2006, the Kwinona Desalination plant started delivering water (excesses
are stored behind the dams they do have) at the rate of thirty-three million
gallons per day, about two thirds of the Carlsbad plant. Then a couple of
years later the Southern Seawater Desalination Project was developed. It now
delivers seventy three million gallons per day, so the total of both plants
is over one hundred million gallons per day. Although the historical average
rainfall in Perth is three times that of San Diego, they know they can’t
count it to supply a growing population, and a climate that is becoming
dryer.

In the links provided in this blog the units are metric (mm of rainfall,
gigaliters of capacity, etc.). They have been converted to English units for
comparative purposes.

A recent Twitter posting included in this blog was a warning that Perth’s
rainfall did not exceed 5.8 inches the last month of their rainy season. San
Diego would have been delighted to get that much rain in a month. That’s
about all we got last year. And they don’t pussy foot around with their
residents. Mandatory limits are in effect. That’s why, despite having 2/3 of
the population of San Diego, they use half the water.

Instead of anxiously looking westward for signs of an El Nino-like saving
rain like our water leaders in San Diego are doing, their peers in Perth
actually met the water issue head-on. Now if it rains fifteen inches instead
of thirty in Perth, everyone can relax. Not so in San Diego as we look to an
even dryer future. Are Western Australians smarter? No, but they know
kicking the can down the road is a fool’s errand.

Desal plants have their own naysayers and problems, particularly with the
intakes and disposal of the brine, that’s why potable recycling is usually
better. It is more energy efficient and cheaper all around. Why aren’t we
taking action like the City of Perth has done? Ask the Mayor, the City
Council, the San Diego County Water Authority’s thirty-six directors, and
the sixteen managers of our twenty-four water districts.

Milt Burgess