Posts Tagged: watershed
I have the privilege of engaging California's communities with the aspiration of safeguarding the sustenance and well-being that its oak-woodland watersheds and the people that are a part of them provide. This millennia-long integrated relationship of humans and land has parallel histories in other Mediterranean parts of the world. The following blog is the first of occasional installments about working Mediterranean landscapes in California and around the globe. Combined they will explore the concepts of watershed functions, working landscapes and Mediterranean climate, vegetation and management. Join me in experiencing these settings, growing our appreciation for the integrated nature of these landscapes and people, and gaining understanding and tools for our tenure as stewards. - David Lewis, director, UC Cooperative Extension, Marin County
I am standing where stream flow begins, in a nameless tributary of the Russian River to the east of Hopland, Calif. This particular spot and location has been a grazing livestock ranch, primarily sheep, going back more than 100 years (learn more). This is one of thousands of spots in a watershed where water comes to the surface, joins in a channel and starts its path downstream. Many of us have stood at a confluence of two rivers or an estuary where a watershed's outfall meets an ocean. These locations are the stream's or river's end, their terminus. Where I am standing, is the headwaters of a stream system, where water is initially released and visible as a thin, shallow bouncing band.
Watersheds collect, store, and transport water. The transport function is performed by streams and rivers. These are dynamic, pervious channel networks each with a beginning and an end. At any part of the network, the channel is that lowest point in the landscape, stretching from one stream bank to the other, and generally widening in the downstream direction, until the stream mouth empties into another water body.
At the other end of a network is the channel head, where the channel begins. This is where I am standing. Channel heads are found in small, intimate folds in the landscape. These depressions are referred to by many names — draws, bowls, hollows — the place in hills where the slopes become shallow and coalesce.
Like an amphitheater, the surrounding hillslopes rise around me. Reaching out at shoulder height, I can almost touch these slopes. The mixed oak woodland and interspersed grasslands are in attendance across these slopes. Ghost pines, live oaks, black oaks and madrones, among other trees, make their stand interspersed with annual and perennial grasses blanketing the ground. This mosaic of vegetation is hosted and sustained by the complex mix of marine sediments that have been pushed up, forming these hills, and erosion carving the stream channel. Below the surface are soils one to three feet deep that have developed from the underlying geology.
It's March 3, 2019, and on the cusp of spring. Between the light breezes, the stream water sings its way downstream. I think back to the intense storms that moved across this part of California the week before and the resulting floods in the lower portion of the Russian River. Those and earlier winter storms soaked into the soil until the soil reached its capacity to hold water. Once the soils were primed, water was released to the channel network. That water is still being released now, days later, and will be for several more months into May or even June. Rainfall for this area and most of California has been substantial, matching amounts not seen since 1983, and definitively ending the nearly five-year drought. This contrast in extremes is the norm for California, meaning the next drought or next flood is only a year away.
Downstream the Russian River is perennial, flowing year-round. But here at the channel head, flow is intermittent on an annual cycle. Rains begin in the fall, with headwater surface flows starting in late fall or early winter, once soils are saturated. This wetting up process reverses in the spring, until the channel head is dry.
At some point this year flow in the headwaters will stop. Saturated soils releasing water laterally below the ground surface, will gradually release less and less water to the channel. Trees and grasses will demand more and more water as they leaf out and grow. As soils pores empty of free water, the remaining moisture is held more tightly to soil particles and plant root surfaces through a physical tension. Eventually the channel head will run dry.
While you may not have the opportunity to visit a channel head and experience the place where stream flow starts and stops each year, you are often closer to one than you think. Driving a rural road or hiking in a favorite park or open space will invariably find you crossing one of these unnamed headwater streams. As you do, give a look upstream, from where the water going past you has come. Up the channel into the bowl is one of the channel heads and headwaters for the watershed you are in.
I don't know when I will get to this channel head again. However, this place where surface flow is initiated will be close in my mind, particularly, as I visit the confluences and estuary of the Russian River, during the wet and dry periods and high and low rainfall years to come.
To learn more about these specific watersheds and research conducted in them this article is suggested. If interested in learning how stream flow is generated in California oak woodland watersheds you may want to read this article./span>/span>
Working with campus experts (such as faculty and staff in the Department of Wildlife, Fish and Conservation Biology) and local environmental and conservation organizations, the volunteer students are improving the habitats for local wildlife and engaging the public in hands-on activities.
This is an extraordinary program that gives the students real-world environmental management skills, along with leadership opportunities and communications experience. Professor John Eadie, Department of Wildlife, Fish and Conservation Biology at UC Davis, said of the Wild Campus program, “Hands-on activity is a huge part of the educational experience.”
A past project — Build a Wild Home Day — involved working with the UC Davis Arboretum on a successful public outreach program to build bird and bat boxes for installation on campus. (Great photos of this program are on the group’s Facebook page.)
The Wild Campus organization has a large cadre of eager and dedicated students who are improvising and making the most of limited resources. However, they are in need of donated field equipment (used equipment is fine) and financial contributions.
Visit the Wild Campus website and Facebook page for a feel-good look at what these ambitious students are doing to improve the environment, along with ways you can help them succeed.
A new wireless data collection system deployed at Duncan Peak, located near the town of Foresthill on the Middle Fork of the American River basin, is part of a new water information system for California. This extensively distributed sensor network will allow for better characterization on the amount of water stored in the snow and the soil throughout the watershed.
This wireless system is part of the research being conducted by University of California researchers as part of the Sierra Nevada Adaptive Management Project (SNAMP) to investigate the impacts of fuels treatment projects on water quality and quantity and how water is routed through catchments. Information collected from these wireless systems includes measurements of snow depth, temperature, relative humidity, soil moisture, and solar radiation. The data will also be integrated into models which will extend the results to areas where no measurements are being made.
UC Professor Roger Bales and a meteorological station data collector.
Using one base station to log all the measurements and broadcast out over the landscape, it connects wirelessly to sensors up to 350 feet away, a distance that can be extended multiple times by placing “hoppers,” or signal relays, between the sensors and base station. This ‘mesh network’ insures multiple readings so no data is lost during transmission. Twenty more base stations are planned for instillation in the American River Basin.
The wireless system is made possible by the development of ultra-low power radios that can run on two AA batteries for up to two years and which can transmit data over long distances using the same technology as a home internet wireless network. This mesh radio network comes from DUST Networks. Researchers Steve Glaser and Branko Kerkez from UC Berkeley, working with Prof. Roger Bales at UC Merced, have also installed a sensor network at their Critical Zone Observatory research site near Shaver Lake to monitor the same hydrologic variables as in the SNAMP sites. If the wireless system drops out due to extreme conditions, such as a snow storm or other malfunction, no problem! Each sensor also logs to a USB stick, from which the data can also be easily retrieved.
Low power computer components used in the snow depth wireless sensor network.
More precise estimates on water storage within a basin will lead to increasingly accurate predictions of water availability for use in hydropower, irrigation, habitat and household consumption.
Duncan Peak meteorological station.