As directed by Laura Dunn, "The Unforeseen" unfolds like a mournful whodunit, with the Earth itself being the victim of the crime.

Taking its title from the poem "Santa Clara Valley," read in voice-over by the poet Wendell Berry in his best angry, Old Testament prophet style, "The Unforeseen" skirts the danger of being simply a tree-hugger movie.

Instead this film, which took the truer than fiction prize at Film Independent's recent Spirit Awards, honors the intricacies of a complex subject. It depicts the battle between the competing interests of developers and environmentalists as it played out over a 30-year period in the area around Austin, Texas, and turns it into a convincing microcosm for land use issues everywhere.

The film favors an indirect approach, burying its aims and easing into its subject matter.

So "The Unforeseen" begins with gnarled old men talking about how difficult farm life can be. Then another, somewhat younger man describes the way the harshness of rural living, the dependence on the sometime beneficence of an often-harsh nature, led him to leave the farm and move to Austin, where he began a career as a developer.

That man is Gary Bradley, someone who can talk almost poetically about development as "painting a picture on a canvas." When he came to Austin in 1972, he considered it "the perfect place to develop" and began putting together what was to be the 4,000-acre Circle C Ranch subdivision.

"The Unforeseen's" refusal to demonize Bradley, whom the press notes refer to as "one of the most controversial real estate developers in central Texas," is one of its strengths. Instead, director Dunn adopts the attitude of veteran political writer William Greider, who says "there's something appealing about developers. They say, 'We're going to reshape the future, we're going to have fun, and we're going to get rich.' They end up wondering 'where did it go off the rails.'" Which is exactly what happened with Bradley.

The first hitch Bradley faced was the savings and loan crisis, which led to the bankruptcy of his company. That was an opening for bigger players like international developers Freeport-McMoRan to enter the Austin scene as his partners.

That company's sketchy environmental record, plus the fact that the Circle C development threatened the health of Barton Springs, a locally beloved spring-fed swimming area, led in 1990 to a tidal wave of public disapproval that killed the project and led Austin's city government to pass a radical anti-growth ordinance.

That, however, was not the end of the story. As related by veteran lobbyist Dick Brown, the state Legislature got into the act and, in effect, overrode the Austin ordinance. As an offshoot of this struggle, a young man named George W. Bush halted Texas Gov. Ann Richards' bid for re-election and ended up in the White House.

As before-and-after footage starkly reveals, everyone's worst fears about Barton Springs came to pass: Runoff from all that development turned it into, says one disgusted observer, "a drainage ditch instead of a stream."

Dunn is too capable a filmmaker, however, to leave it at that. Though "The Unforeseen" has a few too many clips of Robert Redford, its environmentalist executive producer, its strength is its realization that these unforeseen developments are making few people happy. Not the people who move into the new houses, who end up lamenting the crowded sameness of it all, and certainly not developer Bradley, whose life turned out nothing like what he expected. No one who sees this intriguing documentary will want to argue with Greider when he forcefully insists, "We need a more mature regard for the future."