Watershed Ways
Perhaps you've noticed the Russian River Watershed signs newly installed along Highways 128 and 253. You are actually leaving the Navarro watershed when you see those signs--because watershed boundaries are most frequently along ridge tops in our neck of the woods. Some people may ask what the heck does the word Watershed even mean? A good way to think of a watershed is simply as one complete drainage basin, from the ridge tops down to the creeks that flow in the valley bottoms, which flow together to become a river that ultimately drains into the ocean. The Navarro is the largest watershed in Mendocino County. In total it encompasses 315 square miles. There are 5 main drainage basins or sub-basins in this watershed.
There is Rancheria Creek Sub-basin, which starts way up in the hills South of Yorkville and you see running alongside Highway 128 until you get past Fishrock Road. It then continues on it’s way winding through the hills up above Boonville and crosses Mountain View Road where it continues it’s meandering through the hills until it drops down around Philo. Then there is Anderson Creek Sub-basin which comes in from the hills to the right of RT 253 on the way to Ukiah and towards Yorkville. You cross over it just as you drop down into Boonville on your way back from Ukiah. You cross it again as you are leaving Boonville on your way to Philo. It continues it’s journey along the open flood plain in the Valley bottom between Boonville and Philo. And then there is Indian Creek Sub-basin, which starts way back in behind Peachland Road and Indian Creek Road in Philo. You cross over it as you enter into the town of Philo. These 3 creeks come together in Philo down near the end of Rays Road. At this point it becomes the Navarro River. Where a watershed's creeks or river actually begin is called the headwaters. One way of remembering the order in which these streams run together is to think RAIN; Rancheria, Anderson, Indian creeks come together to form the Navarro River.
There are two other major sub basins that continue to feed into the Navarro River as it makes it’s way to the Ocean. There is the Mainstem Navarro Sub-basin that includes Mill Creek that comes down from around Nash Mill Road and Holmes Ranch Road that feeds directly into the Navarro River. The Mainstem Navarro Sub-basin also includes all the area to the South that drains off of this side of Greenwood Ridge. And finally, there is the North Fork of the Navarro Sub-basin that comes in from way up towards Comptche and includes Flynn Creek and the North Fork of the Navarro. The North Fork Navarro is actually what we are seeing as we drive along highway 128 from Flynn Creek Road until you see that open up and empty back into the main stem of the Navarro River. The Mainstem Navarro is actually quite a few miles away to the South of the Highway winding it’s way through the hills. You might get close to it if you were to drive all the way out to the end of Gschwend Road. The North Fork Navarro enters into the Mainstem Navarro about the time we reach Paul Dimmick State Park.
In a few more miles we reach the upper reaches of what is known as the Estuary. This is a very important part of the river system where the ocean’s salt water mixes with the fresh water of the River to form what is known as brackish water. The estuary provides a "nursery' environment for young fresh and saltwater creatures and only certain types of plants grow here. The tides of the ocean, and the freshwater seasonal flows have their effect on this area as well.
All of the different parts of a Watershed serve important functions ecologically. Those details and more on the Navarro Watershed will need to be saved for another time, however. In the meantime, I encourage all of us to look at the watershed as a whole. It can help us to understand and appreciate the dynamics of this beautiful place many of us call home, The Navarro River Watershed.
Written by Linda MacElwee. Email at lsmacelwee@hotmail.com