JOHANNESBURG South Africa's Karoo, a vast arid wilderness, may contain gas reserves that could solve the country's energy problems -- but only through an extraction process called fracking that has greens seeing red.
The sprawling and ecologically sensitive region, home to rare species such as the mountain zebra and riverine rabbit, may hold vast deposits of natural gas in shale rock deep underground.
Once unobtainable, such reserves can now be exploited with new techniques and could serve as a badly needed energy source for Africa's largest economy, which is heavily reliant on coal.
Petrochemicals group Sasol, Anglo American and Falcon Oil and Gas are among those eyeing shale gas in the region, although oil giant Royal Dutch Shell is leading the pack with exploration rights to 90,000 sq km (34,750 sq mile).
But farmers and conservationists are opposed to shale gas development in a parched region famed for its succulent lamb, big skies and rare plant and animal life.
Public concern focuses on hydraulic fracturing or "fracking," in which drillers blast millions of liters of water, sand and chemicals at high pressure into underground rock to create cracks for gas and oil to escape.
A local environment group has vowed to take the matter to court if Shell or anyone else gets the green light.
"We will pursue an interdict against the government and or any other applicable party to reverse any decision to award an exploration license," Jonathan Dean, coordinator of the Treasure the Karoo Group (TKAG), told Reuters.
Environmentalists say natural gas helps reduce carbon emissions as it burns more cleanly than coal or oil.
But the anti-fracking lobby says the technique may well violate parts of South Africa's constitution that enshrine the rights to water and "ecologically sustainable development."
Energy attorney Luke Havemann, who compiled a report presented to President Jacob Zuma this week, told Reuters South African legislation "simply does not allow for the advent of fracking."
The report said Shell's 24 proposed exploration boreholes could use up to 144 million liters of water, putting the company in competition with farmers and wildlife in the Karoo.
But the multinational insists it will not be taking other people's water, even if the exploration leads to more wells being sunk to extract gas on a commercial basis.
"Nobody will go short of fresh water because of our operations, either in the exploration phase, or if there is any further development," spokesman David Williams said in an e-mailed response to questions.
Shell was developing plans to find its own water and would and help meet any community shortages, he added.
The company would also submit an environmental management plan to the government by an agreed April 14 deadline, he added, despite calls for a delay to allow more time for public comments.
Opponents of fracking argue that it produces leftover wastewater containing cancer-causing substances. Supporters insist the practice is safe, noting that it is done much deeper below ground than most water sources.
The U.S. Environmental Protection Agency (EPA) is currently studying the impacts of fracking on drinking water. Initial results are scheduled for release in 2012.
(Reporting by Ruona Agbroko, editing by Ed Stoddard/Ruth Pitchford)