Water flow experiment begins at Grand Canyon

Interior Secretary Ken Salazar opened the river outlet tubes at noon and called it "an historic milestone" and "a new era in which we realize that the goals of water storage, delivery and hydropower production are compatible with improving and protecting the resources of the Colorado River."

The peak flow will last 24 hours from Monday night into Tuesday, and the river will run high for five days.

The heavy rush of water down the river at Glen Canyon Dam is part of a government program to restore the Grand Canyon's ecosystem.

The goal is to wash millions of tons of sediment downstream to create beaches and improve habitat for plants and animals, and protect archaeological sites.

Grand Canyon National Park officials have contacted visitors with backcountry or river permits and advised them to camp on high ground this week, according to The Arizona Republic.

The experiment that could hurt next year's fishing — and complicate hydropower production and water storage — in the name of a more environmentally correct river.

The rush of water churning up sand for new beaches and backwater sandbars was welcomed by many environmentalists and park managers. It's the fourth experimental flush since 1996, and the first since Salazar in May decreed them routine in a 10-year protocol that, weather permitting, could mean mini-floods every year.