Many rivers are more valuable without their dams.  Years ago it was unthinkable, but now dams are scheduled to be removed on the Klamath River.  Robert Service writes in Science News (Nov 13) Four Dams to Come Down:

A tentative agreement has been reached to begin decommissioning four dams on the Klamath River, an issue that has been a hotbed of controversy in recent years. The news was announced today by top officials with the U.S. Department of Interior, the states of California and Oregon, and the utility company PacifiCorp. If the deal goes through, it’s expected to mark the largest dam-removal project ever undertaken.

The agreement marks a major shift in bitter battles over water that have racked the Klamath Basin in recent years and often placed scientists in the center (see Science, 4 April 2003, p. 36). PacifiCorp had been seeking to relicense its dams, and the Bush Administration has long opposed dam removal. The Klamath, which flows from the central portion of southern Oregon to the coast of northern California, is the third most important river for salmon in the West behind the Columbia and Sacramento rivers. Dams along the river provide cheap renewable energy, as well as vital irrigation water for farmers. A drought in 2001 led federal officials to shut off irrigation water, a move that sparked widespread conflicts among farmers, fishermen, and conservationists. With irrigation restored the following year, low river levels contributed to a disease outbreak that killed at least 33,000 salmon, according to a 2004 report by the California Department of Fish and Game.

In the NYTimes, Felicity Barringer writes:

All the parties had coped with worst-case situations in the past decade. In 2001, irrigators had their water shut off, crippling agricultural production. In the dry year of 2002, the Interior Department ordered water distributed to irrigators and tens of thousands of salmon in the Klamath died; in 2007, low salmon populations in the Klamath led to sharply curtailed commercial fishing.

“After living through moments that would tax the character of most anyone, the good people of the basin came together,” Mr. Kempthorne said.

…

The agreement also sets out a requirement for several years of scientific analysis of how removing the dams would affect water quality and fish habitat. The aim is to ensure that the environmental impact of the release of sediment would not be worse than leaving the dams in place. The oldest dam was installed more than a century ago.