Librarian at Large
A Box of Rain
Storm runoff study investigates riparian pesticide management
David L. Brown sets up a flow
collector in an orchard in Orland to sample pesticide runoff as
part of his research project to evaluate the effectiveness of streamside
buffer strips in reducing the amount of pesticide transported from
orchards to local creeks.
Adam Radford assists Krissy Gilbert
in collecting soil samples for her master’s thesis research,
which evaluates the effectiveness of streamside buffer strips in
lessening pesticide pollution.
In the midst of this damp and foggy winter, geosciences professor David
L. Brown can often be found in a creekside orchard scanning the skies
for more rain. Another decent storm would enable him and his team to test
the hypothesis upon which hangs his latest research project, the Riparian
Buffer Strip Management for Water Quality Control, set up at Lassen Lands
almond orchard in northcentral Glenn County.
Will the vegetation planted along Walker Creek reduce the amount of diazinon
runoff into the water? And if so, would farmers and orchardists willingly
maintain such riparian buffers in order to manage pesticides’ effect
on this corner of the planet? Though the swarm of variables surrounding
the project and, for that matter, most issues of watershed hydrology would
drive the average layperson insane, Brown sees them as a means to two
important ends—fostering environmental literacy in students and
contributing to good stewardship of the Earth.
Brown, who in 2001 served as Bidwell Environmental Institute’s science
director, earned a Ph.D. at University of California, Berkeley. From there,
he was hired by the University of Kentucky to direct the teaching and
research activities of a 10,000-acre forested watershed. He’s been
teaching at CSU, Chico for six years.
“When I came to Chico State, I checked around with people I knew
in the environmental industry, and they said Chico State students have
a great reputation for hands-on skills,” he recalled.
The project site near Orland, funded through 1996’s Proposition
204 water bond, includes three test plots near the creek. One, serving
as the control plot, is simply bare Tehama silt. Another supports the
existing weed population, while a third contains purple needle grass,
creeping wild rye, California melic, and deergrass—all native vegetation
adapted to the dry summers. Stainless steel “flow splitters”
have been set up to manage storm runoff and make sample collecting easier.
One collector monitors diazinon concentrations in surface runoff, and
three others collect runoff samples from the plots. Wells dug either three-
or eleven-feet deep monitor shallow saturated zones. A bulk precipitation
collector awaits the much-anticipated rainstorm.
“The big thing that vegetation probably does is make the ground
more porous,” said Brown. “More water can be absorbed and
take the diazinon with it. What you’re doing is slowing the water
down to allow the natural biological and chemical reactions a chance to
break the material down.
“We sprayed diazinon on the ground as a worst-case example of pesticide
loading. Once we finish our setup and the next big rain comes, we’ll
know how it works. If we get a good inch of rain, we’ll probably
get enough water through our system to see it. The problem is if we get
just enough rain to get the water in but not enough to get the water through
to the catchment on the other side, we may get only a partial signal.
But the way we’re set up, we can go back out in a month, spray again,
and try artificial rainfall. We can do a very controlled experiment.”
Along with the Orland project and a full-time teaching load, Brown most
recently has helped the Cherokee Watershed Coordinated Resource Management
and Plan Group obtain funding, through Proposition 13, for a comprehensive
water quality survey of that 95-square-mile area. The watershed includes
not only the community of Cherokee but Butte College and Paradise as well.
He’s also looking into designs of “virtual tours” for
the many desk-bound state regulators in charge of dispersing funds who
“don’t know beans about agriculture.” One such tour
would demonstrate the seasonal life of an orchard, including water and
“There’s a need for these types of projects,” observed
Brown, “and the need is something that’s going to make Northern
California better—and make the world better, ultimately, but incrementally.
Students who want to address this don’t always have to do so through
advocacy. There are plenty of advocates out there. There also need to
be some solutions.”