When the chinook salmon come back to the San Joaquin River, it will be a miracle. But the wonder of the river's restoration won't be in the biology involved, which is well established. Or the engineering needed to bring the river back to life. Most of what is required has been done before.

It's the politics that make this project so remarkable.

Few issues in California, or anywhere in the West, cause as much bitter division as water. Yet in the foothills east of Fresno and the flatlands stretching toward the Sacramento-San Joaquin River Delta, the warring parties have finally put down their arms and are working together on a project that should benefit the environment, the fishing industry and the local economy. Even the farmers at the heart of it all have signed on to the deal, though many of them still wish they could remain set in their ways.

Thanks to recent changes in federal law and a commitment of federal money to the project, the San Joaquin River restoration, debated for nearly 20 years, is about to begin in earnest. The first water for the newly re-created river will flow through Friant Dam in October, if all goes according to plan, and it will then flow into parts of the river that have been dry for decades. Within a few years, thousands of salmon should be swimming upstream through what is now a parched valley landscape.

"When we're done, we'll have a river that can safely convey the flows necessary to restore salmon and other native fish to the river," Monty Schmitt, a biologist with the Natural Resources Defense Council, who has been working on the project for nine years, told me last week. "It means the San Joaquin River is providing fresh water downstream, to the lower San Joaquin and the Delta, stretches of the Central Valley that have water quality issues. We'll actually have a living, connected river.

"In these years when the salmon populations have been crashing throughout California, when the commercial fishery is closed again, restoring salmon to the San Joaquin River is one of the greatest steps we can take to hopefully revive the commercial salmon industry," Schmitt said.

Much of what used to be a wild, scenic river has been transformed over the years into a series of channels and canals, with water moving this way and that to irrigate some of the most productive cropland in the country. Citrus, stone fruit, grapes and nuts are grown there now, along with forage crops for the cows that make Tulare County the No. 1 dairy county in the nation.

Those farms stand to lose as much as 20 percent of their water as the river is restored. But the restoration plan makes it a priority to help them get most of that water back in one way or another. The water district will be allowed to capture more water in flood years and save it for dry years. Canals will be improved and new levies built. New land and new techniques will be employed to store reserves as groundwater that can be pulled back to the surface with wells and pumps.

There is even a plan to recycle water by taking it back out of the California aqueduct south of Fresno after it flows down the river, through the Delta and becomes part of the state's water system. The same water that restores the salmon could then be pumped back uphill and used again, this time for irrigation.

"We hope to get double duty out of that water by taking it the long way around," said Ron Jacobsma, general manager of the Friant Water Authority. "We really need to focus on getting that water back. The project has been in operation for over half a century, and the whole fabric of the community here has been built on having those reliable water supplies."

There's a lesson here for combatants on other contentious issues large and small: It's usually better for everyone involved to settle their differences rather than fight to the death.

At first the farmers fought the lawsuit that sought the river's restoration. After all, it challenged their right to use the water they had been claiming for decades. But once the courts ruled that the river's diversion had endangered the salmon, it became clear that a decision would be issued at some point ordering the restoration. Facing that prospect, the users eventually decided it would be better for them to help shape the plan than to merely suffer its consequences.