Technology is at forefront of water managers' adaptation schemes

The question is whether adaptation strategies can be put in place quickly enough to stave off major disruptions in water supplies and distribution, international experts said at the American Water Works Association's annual meeting here this week.

Utility managers, regulators, consultants and others at the trade group's conference focused on global warming's impact on water resources -- a concern that just a few years ago was seen as the stuff of science fiction.

"The costs for doing nothing far outweigh the costs of mitigating" global warming's damage, said Henk van Schaik, director of the Co-operative Programme on Water and Climate, a research group based in Amsterdam, the Netherlands, where rising seas threaten to inundate more than half of the country's dry land and 60 percent of the Dutch population.

Australia, meanwhile, is bracing for changes of the opposite extreme, said David Garman, executive director of the Environmental Biotechnology Cooperative Research Centre in New South Wales.

While Australia's northern desert regions have experienced a 10 percent increase in rainfall over the past several years, the southeast and Gold Coast regions -- home to Sydney, Melbourne and Brisbane -- have witnessed a 20 percent drop in precipitation since the early 2000s, leading to dire water shortfalls.

"The modeling shows that we're going to continue to get big changes," said Garman, who served 13 years on Australia's National Water Commission and is also president of the International Water Association.

"These are not just increases in temperatures, these are increases in variability," Garman added. "We have to be careful about this, because in some basins we'll have floods, and in the next basin we'll have droughts."

Emphasis on technology, innovation

Such changes will require a new wave of utility innovation, including the development of new technologies and overhauls in system management for both water supply and wastewater.

Wastewater recycling, for example, will become necessary in inland regions where rising temperatures and shifting precipitation patterns conspire to deplete water resources. Similarly, desalination of ocean water will make up an ever larger component of water supply in densely populated coastal zones.

Australia, for example, is developing desalination plants, starting with a West Coast facility that would produce 40 million gallons a day, 20 percent of Perth's drinking water. A second, larger desalination plant is being built in New South Wales and is expected to open in 2010. "Australia is lucky because most of its urban population is close to the ocean," Garman said.

Holland's primary freshwater source -- snowmelt from the Swiss Alps that drains to the Rhine River -- could be compromised by rising temperatures and quickening melt rates in the mountains, which would send greater volumes of water downstream in early spring, when it is least needed, and rob the country of freshwater in summer and fall.

Such conditions have led the Dutch government to pursue a nationwide "climate proofing" strategy, characterized by public and private investment in new water management tools and programs, including efforts to expand the country's capacity to store water.

Such adaptations, including the possible conversion of thousands of square miles of coastal farmland into catch basins for water, are included in what the Dutch government has estimated to be a €300 million to €10 billion investment over the next 50 years.

In Southeast Asia, Singapore is similarly bracing for the hazards associated with warmer temperatures and rising seas. The city-state of 4.7 million people is surrounded by ocean on three sides, and is severed from the Malaysian peninsula by the densely developed Singapore River.

Chang Wui Chain, an executive with Singapore's Public Utilities Board, said water managers are preparing for a 21- to 48-centimeter rise in sea levels that would inundate low-lying coastal areas and allow saltwater to infiltrate drinking water, most of which is stored in surface reservoirs. Evaporation rates from surface reservoirs are also expected to increase as temperatures rise.

Wastewater reuse in Singapore

But, Chain said, "The main concern for Singapore is flooding," which could damage or destroy critical infrastructure, including the city's bustling downtown and commercial districts.

The government has considered erecting massive seaward dikes modeled on the Netherlands' flood control system, but funding and technological hurdles remain.

And despite Singapore's average annual precipitation of 100 inches, rapid population growth and urbanization are beginning to seriously strain existing freshwater supplies.

To meet such challenges, Singapore has turned to technological innovation. It operates one of the largest desalination plants in Southeast Asia and has developed one of the world's most advanced water reuse programs.

The reuse program, called "NEWater," relies on advanced microfiltration, reverse osmosis and ultraviolet exposure to clean and treat wastewater for potable consumption.

NEWater has been recognized as an international model for innovation in water management, most recently winning the "Environmental Contribution of the Year" award from the London-based group Global Water Intelligence.