On a hot day in early September 2024, researchers from UC Davis are in the creek, setting up transects to measure its size and shape. Olive trees, willows, blackberry brambles and dried grasses share space here with scattered bits of trash — soda bottles, plastic bags, broken toys, paper plates, a pizza box. A woman shuffles below the shade of an oak. An empty wheelchair is parked under a tree. A shirtless man on a bike emerges from a trail and quickly apologizes for “being in the way.” He’s not, Professor Gregory Pasternack assures him: “We’re just researchers from UC Davis measuring the stream.” As homelessness and climate change increase, urban streams become more susceptible to flash floods, heavy winds and pollution and more dangerous to those sleeping alongside them. The research could yield data to better understand how to make positive changes and inform policies. They are joined by Costanza Rampini, an associate professor of environmental studies at San José State Universi...