Going with the flow

Big Chico Creek, the waterway that originates at an elevation of 5,400 feet in the eastern foothills and flows 45 miles to the Sacramento River, has garnered an increasing amount of attention in the past dozen-plus years from ecologically minded groups looking to monitor its health.

One of those groups is the Big Chico Creek Stream Team, which gathered Saturday (April 11) at Five-Mile Recreation Area for a three-hour lesson in how to gather water-quality data at various spots along the creek. This marks its 13th year monitoring the local waterway. Three days later, eco-consulting firm FISHBIO released the results of its second annual fish count, used as another way to measure the creek’s health.

The Stream Team, which attracted 32 volunteers at this year’s training, is headed by local biologist Timmarie Hamill, who’s been active with the operation since it began.

“We get anywhere from 10 to this many every month,” she said, nodding toward the gathering of volunteers. “We divide into groups and have team leaders. Some of them have been coming here for 10 years, so they are training the new volunteers today.”

The data gathering, held on the second Saturday of the month beginning in May and running through October, is conducted at 10 spots along the creek from the upper watershed in Butte Meadows, down through Forest Ranch and Upper, Middle and Lower Bidwell Park, through the city along Rose Avenue and out to where it empties into the Sacramento River.

The data documents the water’s pH levels, clarity, temperature and oxygen levels.

“We also do bio-assessment, which means taking a look at the aquatic diversity of the juvenile insect nymphs that live in the creeks,” Hamill explained. “If they are there for two or three years and known to be sensitive to pollution, then you can assume the creek is in pretty good shape. But if you just have black flies and roundworms, you’d be concerned.”

Collecting data over time allows the Stream Team to track changes, which are beginning to show, Hamill said.

“We see with urban development and more people in the valley a slight decline in species like macro-invertebrates and aquatic invertebrates,” she said “That is due to both changing natural conditions as well as ones that humans are having an influence on.”

The information gathered is submitted to the State Water Resources Control Board, which conducts a Surface Water Ambient Monitoring Program (SWAMP).

Erick Burres, the citizen monitoring coordinator for the board, was on hand Saturday to help coordinate the effort. He told the local volunteers that Chico’s Stream Team model will be used as a pilot program for other citizen monitoring groups taking part in SWAMP.

“Throughout California, we have hundreds of organizations where volunteers come out to test the water to produce actionable data so we can better steward and protect and restore our streams,” he said.

The most recent SWAMP report was released in 2012 and the Central Valley region assessment concluded: “Some to moderate water toxicity was widespread throughout the agricultural and urban-agricultural areas in the upper Sacramento River watershed, including the Colusa Basin, the area surrounding the Sutter Buttes, and the eastern valley floor between Chico and Lincoln.”

It also reported that “sediments downstream of the city of Chico showed some to no toxicity, while downstream of Yuba City, Gilsizer Slough showed high toxicity at multiple sites.”

On Tuesday (April 14), FISHBIO, which works with the Stream Team, released its 2014 Big Chico Creek fish count based on the observations of divers wearing snorkeling gear. It compares statistics from surveys taken in 2013. The rainbow trout population appears to have dropped by as much as 75 percent at the Big Chico Creek Ecological Reserve, the report reveals, and only two brown trout were observed there last year, compared with 16 in 2013.

Other fish populations remained consistent, including the Sacramento sucker, of which 38 were counted in 2013 and 36 in 2014.

Gabriel Kopp, director of operations for FISHBIO, cautioned that there are several potential explanations for the apparent drop in the trout population.

“Fish move around a lot and might move and collect in places that we can’t see,” he said. “That could be because they are seeking oxygenized areas of the creek. So the numbers might be shifting [to other parts of the creek] rather than plummeting.”