Due out in mid-September, the “State of the Roaring Fork Watershed” report contains a number of interesting facts about the watershed that shapes life in the local region.

“A watershed is an area of land where all the water flows to one place,” according to the Roaring Fork Conservancy, which also has information about the watershed on its Web site.

The Roaring Fork River watershed includes all the rivers and streams that eventually flow into the 70-mile-long Roaring Fork River, which in turn flows into the Colorado River in Glenwood Springs.

The headwaters of the Roaring Fork River are in Independence Lake at an altitude of 12,490 feet, above the upper Lost Man trailhead near Independence Pass.

The Roaring Fork River is the second largest tributary of the Colorado River in the state, yielding an average of almost 1 million acre feet of water, or 306 billion gallons, per year. An acre foot is the amount of water required to cover one acre of ground to a depth of one foot.

The watershed, comprised of 1,962 miles of rivers and streams, encompasses 1,451 square miles (about the size of Rhode Island) and includes most of Pitkin County and parts of Eagle, Garfield and Gunnison counties.

The highest point in the watershed is 14,265-foot Castle Peak about 15 miles south of Aspen. The lowest point is at 5,800 feet at the confluence of the Roaring Fork and Colorado rivers in Glenwood Springs.

The draft report notes that “76 percent of the watershed is federally managed, but public land within 150 feet of the streams and rivers decreases that number to 32 percent, which means that the majority of the watershed’s riparian corridor (is) in private or local government ownership.”

Generally, about 75 percent of the land in the watershed is public and 25 percent is private.

The watershed can be divided logically into nine sub-watersheds, including four on the Roaring Fork River itself.

The Fryingpan sub-watershed has the most stream miles — 279 — and the Crystal River sub-watershed is the largest, at 325 square miles.

The major rivers and streams in the watershed include, in addition to the Roaring Fork River: Maroon and Castle creeks, Snowmass and Capitol creeks, the Fryingpan River, the Crystal River and Cattle Creek. Other significant streams include Lincoln Creek, Hunter Creek, Brush Creek, Woody Creek, Four Mile Creek and Coal Creek.

The estimated population of the watershed in 2005 was 40,000.

— Brent Gardner-Smith