Mega litres of water needed to remove thirsty trees

Posted by: Saving Water SA (Cape Town, South Africa) – partnered with Water Rhapsody conservation systems – 24 July 2010

The biggest challenge facing Grahamstown’s innovative R60 million proposal to turn invasive plant species into much-needed electricity is finding 75000 litres of a water a day to keep the 20-year project going.

A thirsty gum tree sucks up 1000 litres of water or more a day

With the City of Saints currently in the grip of a severe drought, local residents on Thursday night (July 22) expressed concern that there would not be enough water for everybody.

With the scheme aimed at saving water by chopping down and burning thirsty, illegal invasive trees, the irony of using large amounts of water to save even larger amounts of the precious liquid was not lost on the 20-strong crowd of interested and affected parties.

Responding to a question about “creating a dangerous situation” by expecting existing Grahamstown residents and businesses to “use less water” in dry times to keep the project going, Coastal and Environmental Services expert Dr Kevin Whittington-Jones admitted the issue had been discussed for “several months”.

He said the project – funded by the Nollen Group, an international environmental finance company with projects all over the world – was “well aware” that the industrial area where the wood burning facility would be situated “had been experiencing water shortages for several months”.

Nollen Group representative Charlie Cox said the project did not need “clean water from Grahamstown”, thanks to installing its own reverse osmosis system to demineralise water before use.

The water was crucial to cool the equipment that would be used to produce 3MW of power a day.

Project supporter Dr Garth Cambray – who is at the forefront of local green energy initiatives – said upgrades to the present water situation included building more storage reservoirs and tapping into water from the Orange River.

Cox said it was hoped these upgrades would be in place before the facility was up and running by its earliest opening date in 2012.

He admitted, however, “we cannot shut down” the multi-million- rand facility – even if the water situation reached crisis levels.

Another concern revolved around the impact of heavily loaded trucks on local roads, especially dirt ones in outlying areas, trying to deliver six-ton loads of wood to the furnace around the clock.

Cox said there would be short- term relief on strained water resources because the project backers had to cut and store more than two months’ supply of wood before they could even fire up the furnace.

About 400 tons of alien wood had to be harvested from within a 60km radius of Grahamstown every month for the project to survive.

According to one unidentified local expert, as much as 23 percent of South Africa’s water was lost to alien vegetation consumption.

“The more alien vegetation we can get rid of, the better.”

According to Dr Kevin Igbinigie, the CES scientist who gave the presentation, a basic assessment report would be compiled based on the input during Thursday’s public participation process.

Although the bulk of the small but knowledgeable crowd supported the project proposal, other concerns included how the funders would prevent potential stock theft losses on farms that were contracted to supply alien vegetation.

Smoke emission would comply to strict EU standards and ash from the burnt wood and leftover brine from the water treatment would be reused on citrus farms as close as the Sunday River’s Valley.

“If we clear 10000 hectares of invasive woodland we will release a significant amount of water into the catchment area.”

With a thirsty single gum tree sucking up 1000 litres of water or more a day, and pines accounting for at least 500 litres , it is easy to see why removing the trees is a government priority. Finding the water to keep the facility going is still, however, the biggest concern.

By: David MacGregor
Source: Dispatch Online

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