Runoff from Phoenix Lake above Ross

The slopes and ridgetops of Marin County's watersheds don't just provide dramatic scenery. They also delineate the borders of basins where rainwater, brought ashore by winter storms, is stored and eventually released, either naturally or by human design, to all of us -- plant or animal -- living in their shadows.

Aside from winter rain, the watersheds on the western slope of Mount Tamalpais are crowned with grand stands of primordial redwood forests blessed by summer fogs from which these old-growth trees, including bay laurel, distill water. That process provides ground moisture, filling springs, streams, and creeks.

Water, from rain and fog, is the lifeblood of countless thousands of plants; animals, both wild and domesticated; and, of course, humans. In the early days, when the county's watersheds were free to flow as nature dictated, the cold, clean water spurred anadromous fish - those that migrate -- like steelhead trout and coho salmon, to spawn.

So What Is a Watershed?

John Parodi, a watershed education coordinator with the Novato-based Bay Institute, often tells the elementary school students he leads on field trips to cup their hands and imagine that the bowl they've created is filled with water. Then he encourages them to envision that water running out through their fingers and into the sea.

"That's pretty much what the rain does when it falls on the county's hillsides and slopes," he said during an outing along Mill Valley's Old Mill Creek with a group of local youngsters.

Others have different ways of explaining watersheds. "Simply put," says Todd Steiner, executive director of the Forest Knolls-based Salmon Protection and Watershed Network (SPAWN), which is a project of the Turtle Island Restoration Network, "a watershed is a drainage basin usually named by the waterway in which the falling precipitation drains."

Trouble in Paradise

West Marin watersheds are unexcelled in their beauty and biological diversity. The Tomales Bay watershed alone has nearly 900 species of plants and 490 species of birds. And while the connecting Lagunitas Creek watershed today has the largest documented population of endangered wild coho salmon left in California -- a success story related to years of environmental actions -- there is trouble in this paradise, its protectors claim.

The Lagunitas Creek watershed, advises Steiner, "is critical to the survival and recovery of wild salmon along the Central California coast," but Steiner believes it remains "under significant assault from current development plans." Growth weighs on his mind. "It feels like we are losing ground. All the restoration in the world won't protect the salmon and its critical habitat if legislators allow new developments that destroy additional habitat at a pace faster than we can fix the problems of the past."

Also causing problems for the natural flow of water: impermeable surfaces associated with houses, roads, and parking lots, which, says Steiner, "have interrupted the hydrological cycle, causing the water table to drop and erosion and sedimentation to increase."

A Creek Runs Through It

Lagunitas Creek notwithstanding, almost half of western Marin County is publicly managed for resource protection, and this area of small rural communities, grazing cattle, and vast stretches of undeveloped land stands in sharp contrast to the county's busy eastern section.

Sitting in the middle of the urbanized core of the county is Corte Madera Creek and its watershed, which reaches from San Francisco Bay into the foothills of Mount Tam. Some 44 miles long, Corte Madera Creek has approximately 29 named tributaries - and the creek and its watershed represent an example of both the promise and the challenges facing the county's watersheds, particularly in intensely developed areas.

"A watershed integrates everything that is happening in a region," says Sandra Guldman, Friends of Corte Madera Creek board president. "It reflects the land use and the type of soils, and is a history of the watershed and its uses, past and present." Like Steiner, Guldman maintains that one of the major problems is the inability to get enough water into the system because of impermeable surfaces.

Another major problem: Most of the restoration work has been on public property. "The local city governments have been helpful and easy to work with," Guldman says. "Not so with many of the private landowners, even though there are some major projects that, if we had the cooperation, would really improve our watershed."

Still, for the past 11 years, the nonprofit Friends, with 10 board members and about 40 volunteers, has been tireless in its efforts to fix the things that ail the waters of the watershed.

Among its projects on the creek's behalf -- building up eroded culverts that impair remaining salmonid runs; removing physical barriers in the stream that also impact fish; planting riparian vegetation and working on creek banks to keep them from falling into streams, for erosion control; and conducting surveys on the watershed streams, including water quality sampling.

FOR MORE INFORMATION

SPAWN: www.spawnusa.org

Friends of Corte Madera Creek: www.friendsofcortemaderacreek.org

Work is under way to help protect the Miller Creek watershed in the Lucas Valley/Marinwood area north of San Rafael. To learn more, visit the Miller Creek Watershed Stewards page, hosted by the Marinwood Association, www.marinwoodassociation.org