Know your watershed

by Rick Coates

I am amazed at the number of blank stares that I get in response to the question “What is your watershed?” If I had asked what neighborhood they lived in or what street they lived on, they would answer immediately. Yet a question about water, an absolute necessity for life, elicits perplexity.

In some cases it is the word “watershed” that they do not know. Your watershed is the entire upland area, from ridge top to ridge top, that collects, stores and releases rain water surrounding your home together with the creek or river that drains that area. Watersheds are usually named by the creek or river that drain them such as the Santa Rosa Creek Watershed, but they include all of the surface land that drains to that watercourse.

City folks often know not their watershed because it is underground. Rain flows from their roofs to the curb and down the culvert drain. Out of sight, out of mind. No visible creek and the related watershed disappears. Or their waterway no longer bears the name of a creek. Instead it is called a “flood control channel” and is straight as a city street. Most likely, though, most folks have never thought of how important the watershed is to them and how they effect it. Until a flood washes through their living room. You can bet that the citizens of Guerneville know their watershed. Or until gasoline bubbles up in the bathroom tub as happened in the Roseland neighborhood of Santa Rosa. Or until their well runs dry. Or until the salmon disappear.

Take some time to get out a map, locate your home and note the creek or river closest. Thomas guides or Google Maps show greater detail but topographic maps better define the drainage area. Actually you live in several watersheds. The “highest” order watershed is the headwaters or tributary of the nearest creek. Each time the creek flows into another larger creek it drains an even larger watershed. The final and largest “first order” watershed drains to the sea.

For example, consider Santa Rosa Creek Watershed, a fifth order watershed. Santa Rosa Creek, which starts in the Mayacmas Range east of Santa Rosa, flows south to the juncture of the Valley of the Moon and Rincon Valley. Along with the water flows pesticide and herbicide residues washed off the nearby vineyards. Along the way Brush Creek joins Santa Rosa Creek. Therefore those who live in the Brush Creek watershed also live in the Santa Rosa Creek Watershed. At E street in downtown Santa Rosa, Santa Rosa Creek dives underground flowing beneath the Santa Rosa City Hall hidden from life-giving sunshine. When it emerges just west of Highway 101 near Days Inn it has become the “Santa Rosa Flood Control Channel”, straight and true. By this time the drainage from city streets and parking lots has joined the flow. It caries nice additives like garden pesticides, gasoline, oil, and detergents. Soon thereafter, near Llano Road, it joins the effluent from the Regional Wastewater Treatment Plant falling into the Laguna de Santa Rosa Flood Control Channel, a fourth order waterway which meanders sluggishly and darkly through the Laguna de Santa Rosa Watershed. It is here that animal waste tea joins the soup. The Laguna is a third order Watershed. The water and its pollutants then join the waters of Mark West Creek, a second order watershed. Mark West Creek together with its load of treated sewage effluent joins the Russian River Watershed just downstream of the Sonoma County Water Agency’s drinking water intake. The Russian River is a first order, if not a first class, watershed. It is fed by many smaller watershed some contributing agricultural fertilizers and pesticides and some contributing silt from logging operations.

Its pretty obvious that what happens upstream of the drinking water for most of Sonoma County is important. Its important for the fish too. Pesticides from home and farm wash into the stream. Many pesticides aside from being toxic themselves contain a wetting agent known as nonyl phenol. Many detergents also contain nonyl phenol. Nonyl phenol, an estrogen mimic, has been shown to effect the salmonid reproductive cycle. Salmonids must readjust to salt water when they return to the ocean. Unfortunately, small concentrations of nonyl phenol can damage their ability to properly adjust to sea water. The result: these salmon fail to thrive and seldom return to spawn. Excess silt running off denuded hillsides can actually confuse migrating salmon and steelhead causing them to end up in a creek for which they are genetically unsuited.

Forests, both upland forests and riparian forests, play an important role in cleaning the creaks and rivers of silt and pollutants. What is upstream in your watershed matters. Forests hold water and release it slowly throughout the year, reducing flooding. Trees, especially redwoods, filter prodigious quantities of water trapping pollutants in their trunks. The transpired water gets recycled to the forest by fog precipitation. Consequently, it is important to monitor the forest condition within your watershed.

What’s downstream matters too. Pollutants carried by tributaries into the main stem below your watershed can kill fish before they ever reach your stretch of the creek. More and more salmonids must “run the gauntlet” before reaching spawning habitat. After spawning, salmon die and their decaying bodies provide necessary nutrients and food for other creatures. Wildlife require riparian corridors up and down the length of the watershed (including within cities!). It is particularly important that wildlife have access to clean drinking water. Zoning should provide development setbacks from the creek to protect wildlife habitat and provide sufficient riparian forest and wetland to cleanse the runoff waters.

A healthy watershed provides a year round source of water for forests. Forests provide an even, year-round flow of water to the creeks and rivers. Watersheds are crucial to the health of forests. Forests are crucial to the health of the Watersheds.

Does your watershed have an active group of citizens that monitors and protects it? If not, Forest Unlimited would like to help you organize one. If you do, Forest Unlimited would like to provide your group with a forest protection training. Forest Protection Workshops, custom scheduled for your group’s convenience, provide an understanding of the political and legal tools your group can used to prevent abusive logging or riparian damage in your watershed. For more information contact us at 707-632-6070 or visit