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A River Runs Through It

On the Banks of the Historic American River, Professors and Students Keep Watch Over California Waterways

Sac State hydrogeology professor Tim Horner on the American River in SacramentoWhen your campus borders the legendary American River, you can’t help being a nosy neighbor. Sac State researchers are looking into the good, the bad and the ugly—fish, floods and freon—in not only the river next door, but waterways throughout California. Right here in River City, CSUS programs are encouraging healthy salmon habitat, warning citizens of flood risk and stemming road runoff pollutants statewide.

Fish Story

Leaky pipes provoke humans to call the plumber. Leaky streams may provoke salmon to spawn.

Sac State hydrogeology professor Tim Horner and a team of grad students are looking at the physical and chemical conditions that Pacific salmon need for spawning. It’s an issue of great concern throughout the West, because spawning numbers in many Western streams are only 10 percent of what they were historically.

By now, we’re familiar with the salmon’s Herculean efforts to return to familiar
spawning grounds, but Horner’s research indicates they may also be picky. “Year after year they go back to the same place on the same gravel bar,” Horner says. “Why do they like some areas and not others?”

Salmon swim past stretches of river that seem to be comparable in water flow, velocity, depth, the grain size of the gravel, and surface water content only to spawn in a similar gravel bar.

Horner’s hunch points to “leaks” in the river. Working on gravel bars on the American and Cosumnes Rivers, Horner and his students measure the amount of water percolating through the sandy bottom of the streambed.

Though Horner admits he’s not a “fisheries person,” the work he and his students
are doing may directly impact salmon survival. Working with the Department
of Fish and Game, CalFed and the USGS, he is focusing specifically on habitat.
He presented his preliminary findings at the Geological Society of America meeting last fall.

Graduate student Noel Bush with Professor Tim HornerThe answers are important because state and federal agencies are spending a lot of money on habitat restoration. Horner says they need to consider what condition
the habitat should be in when the agencies are finished.

The findings so far: “Leakage is a bigger issue than we’d thought,” Horner says. “If
there is a lot of leakage, the salmon seem to like it. If there’s not much, they don’t.”

Leakage varies from month to month and year to year. Horner thinks the
fish pick up chemical signals from the gravel bar that could be influenced by the flow through the underlying ground. To determine what’s sending those signals,
the research team takes measurements of the flow and leakage from as far as 18 inches below the surface. They also check for concentrations of common chemical components.

One area they study is a gravel bar on the American River near Hazel Avenue
where salmon consistently spawn. The bar has both a “downwelling” area, where water leaks through the streambed, and an “upwelling” area, where water is percolating up from the water table into the stream.

Here’s where chemical makeup enters the equation.

The researchers looked at the dissolved oxygen content at various spots on the popular spawning site. In the upwelling areas of the bar, the oxygen values were much lower than expected—even at relatively shallow depths in the gravel. Downwelling areas maintained a high oxygen content to depths of at least two feet.

Eggs need oxygen and nutrients, leading Horner to wonder if the low oxygen content in upwelling areas is preventing some eggs from hatching and surviving.

This spring Horner’s team returns to the areas it looked at prior to last fall’s spawning season to see if the theory “holds water.”

Rolling on the River

While Horner is concerned about the river’s occupants, another CSUS group is looking out for those who live on land.

Water supply—too much or too little—is a favorite topic during Sacramento Valley
winters. Lack of water helped spur the current energy crisis when hydroelectric power supplies were threatened. At the same time, some areas are still recovering from the devastating floods of 1986 and 1997.

Efforts to predict, or at least track, water flow and water supply are supported by a massive network of streamflow sampling stations throughout California which funnel information through the U.S. Geological Survey Water Resource Division, housed on campus since 1997. The gaging stations monitor discharge and water quality every 15 minutes, giving continual assessments of the water flow from hundreds of rivers, creeks and streams.

The USGS operation at Sac State serves as a clearinghouse, publishing results from about 700 stations, most of which are operated in cooperation with state agencies, counties, water districts and utilities. All the data from gaging stations scattered throughout California’s river basins are fed to a lab in Placer Hall where updated information is posted on the Web hourly. Readings from the website are used by emergency officials, water districts, utility companies and even recreational water users like fishermen and kayakers.

The stations aren’t much to look at—one on the American River visible from the Guy West Bridge resembles a rusty shed—but inside they’re stocked with high-tech equipment including computerized sensing equipment, multiple recording devices and a satellite platform.

In addition to keeping tabs on the campus’ closest water neighbor, the USGS employs a small army of students. In addition to geology students, USGS also hires chemistry, environmental studies, geography, biology and even English majors.

The agency’s unique relationship with the University allows at least 30 students to work on top-level research projects. While the USGS has a presence on other college campuses, the scale of the CSUS Graduate student Noel Bush with Professor Tim Horner operation is unusual, says Michael V. Shulters, California district chief of the USGS, “Bringing an entire district office on campus was a first.”

Some of the students are looking at pesticide runoff in local creeks and streams. “It’s a critical issue in what happens to the Delta. And students are essential cogs in that wheel,” says Walt Swain, a USGS hydrologist.

Pictures of the USGS gaging station next to Sac State are available online at To see the latest stream gage data, visit

Water Under the Bridge

The state’s water supply often runs afoul of products from another California staple— the automobile.

When does a transportation agency need a water watchdog? When the roads you manage are the source for trash and chemicals that end up in rivers, lakes and
even the ocean.

In the mid-1990s, the California Department of Transportation, the statewide organization that oversees California’s highways, found itself with an environmental headache on its hands—it had been successfully sued for violating the Clean Water Act. To the rescue came Sac State’s storm water research group.

The group, part of the Office of Water Programs, has been the brains behind an all-out assault by Caltrans on water-borne road pollutants. Solutions have included studies on herbicides in North Coast streams and measuring the trash carried by storm-swollen rivers onto Southern California beaches. They’ve steered Caltrans toward construction techniques that are better for the environment. And they’ve helped establish new approaches to controlling polluted runoff such as detention basins and drain inserts.

Water pollution from roads may seem like a drop in the bucket compared to all the other environmental problems the state faces. But the number of buckets warrants attention.

Ramzi MahmoodEach year, millions of gallons of water wash across the 15,000 miles of freeways and highways Caltrans maintains. The research group fills an important niche for Caltrans, says Ramzi Mahmood, founder of the storm water group. After all, the agency is charged with developing highway and mass transit systems, not protecting water.

“We’re trying to help Caltrans find out how big a problem they have and then to find cost-effective ways to control it,” Mahmood says. The storm water group began with a $20,000 grant and now has an annual budget of $2.3 million, all through contracts with Caltrans.

Current projects include researching methods of detecting pathogenic organisms in storm water, testing different methods of reducing soil erosion, inventing new treatment technologies and evaluating the cost and benefits of storm water treatment.

To learn more see

New Master's Program

Water research at Sac State received a shot in the arm this academic year with the addition of a new master’s degree program in the geology department.

The master’s program, which got underway in the fall, is finding a willing audience of undergrads seeking advanced degrees, as well as previous graduates already working in the industry.

Because of the department’s strong reputation for water programs, much of the demand for classes is in the booming field of hydrogeology, says geology professor Tim Horner, who coordinates the master’s program.

“It’s a great market for students. If I had three times the students, they could still all get jobs,” he says.

One of the appealing aspects is the opportunity to get involved in research projects. For example, two master’s students are working with Horner on his salmon research, while others are employed as research assistants with the USGS.

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