Restoring America’s rivers, one creek at a time

Lillian Sanders, (she/her)
Hometown: Sebastopol, California
Major: BS Computer Science, '26, MS Earth Systems, '27 
Internship: American Rivers

Lillian Sanders reflects on her experience collecting and analyzing water quality data at Marsh Creek in Contra Costa County during her internship with American Rivers.

One of the first things I learned during my internship with American Rivers was that almost every person in America lives less than one mile from a river. Many forms of life depend on these rivers for hydration, habitat, sustenance, recreation, and cultural practices. Despite this significance, many of us are unaware or unable to access our nearby rivers due to pollution, damning, channelization, or neglect. The 80 percent of people who live in American cities are especially cut off from their rivers, as urban creeks are often hemmed in by concrete channels, polluted with trash or stormwater runoff, and fenced off from communities.

Marsh Creek, which flows through Contra County, California, is one such urban creek. With its headwater in eastern Mount Diablo, this creek runs through farmland where treated wastewater, stormwater, and farm runoff flow uninhibited into it. Marsh Creek then travels through the communities of Brentwood, Oakly, and Antioch before flowing into the San Joaquin River and the greater Delta. The Sacramento-San Joaquin Delta, of which Marsh Creek is one small tributary, is the water supply for 23 million Californians. In the past twenty years there have been ten fish kills in Marsh Creek, the majority of which were caused by low dissolved oxygen levels. Despite these challenges, the creek remains a habitat for Chinook salmon, river otters, muskrats, green herons, western pond turtles, and other fish and wildlife.

Finding Marsh Creek to be a river in need of restoration and protection, American Rivers worked in partnership with Contra Costa Flood Control, the Water Conservation District, and the City of Oakley to restore 5,000 feet of riparian corridor at the confluence of Marsh Creek, Dry Creek, and Sand Creek. The goal of the Three Creek Project is to improve vegetation and flood capacity by widening the channel of the river and planting native grasses, bushes, and trees. The newly widened riparian zone provides flood protection by allowing the river to rise and fall naturally without overflowing its previous strict channelization. The trees prevent erosion and provide shade, which lowers water temperature and makes the river more habitable to Chinook salmon and many other species.

Monitoring is an essential part of any restoration effort, and for this portion of the project, American Rivers worked with Earth Team, a nonprofit dedicated to supporting urban youth in becoming environmental stewards. Earth Team students worked with American Rivers staff to install water logger devices throughout the Three Creeks Project site, which immediately began to track water temperature and dissolved oxygen levels.

By the time I arrived on the scene, the Three Creeks Project site was a strikingly beautiful pocket of nature tucked behind a Brentwood neighborhood and next to a well-used recreational path. The creek flowed unrestricted through a wide riparian zone lush with vegetation, even on a hot sunny day in June. Birdsong and insect chirps filled the air while bikers and walkers meandered past.

Each water logger throughout the site was housed in a PVC pipe zip-tied to a brick at the bottom of the creek and anchored to shore with a sturdy rope. Accessing the loggers required wading waist-deep into the cool water and pulling up the algae-covered contraption. It was surprisingly peaceful to stand in the creek, feeling the tickle of plant matter and nibbling fish at my ankles, protected from the hum of city noise by a buffer of sweeping willows, and then reach blindly for the logger in the murky water. Once freed from its housing, the logger was plugged into a computer, and we watched months of data accumulate onscreen. We then returned the logger to the river and moved on to the next one.

A few days later, back in my clean and dry workspace, it was time to analyze the data we retrieved from the river. Using R, I found the average hourly and daily temperature and dissolved oxygen levels, both for each individual probe and for the Three Creeks Project site overall. While there were only three months’ worth of preliminary data, I was still able to observe the gradual increase of water temperature with the shift from spring to summer, as well as the dramatic temperature changes from the one probe whose surrounding water unfortunately dried up. I also observed the fluctuation in dissolved oxygen from day to night, following the respiration patterns of algae and the gradually increasing seasonal temperature.

Working on my computer, about as far as I could get from standing in the creek fishing out probes, I could practically still smell the damp soil and feel the trailing branches of the willows. Being a part of the tail end of this many years-long project to make this one small part of one small creek better, I felt deeply connected to American Rivers’ mission to improve rivers throughout the nation, regardless of their size or stretch.