The Hetch Hetchy valley, which in the eyes of many rivals Yosemite in sheer drama and beauty, was flooded in the 1920s to supply water and power to California residents. Now environmentalists are bolstered by a recently released government report stating that the restoration of the valley would be both viable and potentially desirable.

The dismantling of the dam in Hetch Hetchy would represent a symbolic act of renewal while providing an invaluable learning opportunity to test best practices for environmental reclamation in a living, breathing laboratory.

At the moment we really don't know what exactly will work best unless we give it a go,' said Joy Zedler, an ecologist at the University of Wisconsin, who has created a phased restoration plan. Scientists hope to learn much about how to restore a landscape from what is likely to be little more than a moonscape of mud when first revealed. That knowledge will boost reclamation projects around the world. Zedler believes they will amass information that will be used globally

The proposed project has gained widespread support, including that of Harrison Ford, who was involved in making a documentary that backs the plan. However, cost remains the biggest hurdle to the successful implementation of the project, with estimates ranging from $1 billion to $10 billion all in.

Despite the cost hurdles, the plan is not without precedent. In the Florida Everglades over $10 billion has been set aside to restore threatened wetlands. A similar effort in densely populated California would present a startling message of environmental values that would be sure to gain the attention of citizens and policy makers the world over.