Editor's Note: NSPR reporter Sarah Bohannon went on a ride-along with the state Department of Water Resources to learn why Butte County is increasing groundwater monitoring and to see exactly how groundwater levels are monitored.
July and August are when groundwater use is the highest in the northern Sacramento Valley. With many farmers getting little or no surface water this year, it’s likely that use is going to go up even more this summer. To see what one county — Butte — is doing to be proactive about this increase in pumping, I shadowed April Scholzen at six wells in the northwest area of Chico. If she weren’t with me, I would have had no clue that most of the wells we measured were wells. They were all over the place and none of them looked the same. But for a water resources technician, like Scholzen, wells are pretty easy to spot. It also probably helps that she’s been working the route for about five years.
“You get good at it after a while — recognizing them,” Scholzen said.
It’s not normal for Scholzen to be in the field during June, but because of the drought, Butte County officials have asked the Department of Water Resources to help them increase their valley groundwater measurements from a few times a year to once a month – at least during the spring and summer season.
The two agencies monitor about 130 wells in the valley region of Butte County. It’s a number that Scholzen said takes her about a week to get through. She measures three different types of wells: domestic, irrigation and observation wells, which are solely used for collecting data.
How groundwater is measured
Butte’s observation wells are the easiest to monitor. They’re equipped with a piece of digital equipment called a data logger. It allows a censor to be installed in the well that captures certain information, like pressure and water temperature, or more importantly in this case, water levels. All Scholzen has to do is upload the data onto a hand-held computer.
Scholzen also takes hand measurements. One way she does this is with a device called a sounder, which is a reel of electric measuring tape with a piece of metal on the end called a transducer. To get the measurement, Scholzen takes the metal transducer end and slips it into the well’s access hole. She lets the weight of the transducer unravel the long spool of electric tape, then waits to hear it hit water. After that she just holds the sounder in that position, reads the measuring tape and writes the measurement down in her field book.
“The sounder is easy because you put the sounder down in the well and when it beeps you’ve hit water,” Scholzen said. “But you can’t use a sounder on all wells. Sometimes you have to use a steel tape.”
Unlike the sounder, steel tape doesn’t let Scholzen know when she’s reached water. To figure it out she covers the tape in blue chalk and feeds it into the well. When she pulls the tape back out, she looks for the highest point on the tape where the chalk has been washed away. From there she just subtracts that number from the amount of tape she fed into the well — and that calculation gives her the new measurement.
Current groundwater levels
At one well measured, Scholzen got a measurement of 44.6 feet. The year before, in fall, the measurement had been 46.9 feet.
“So we’re seeing levels that are approaching fall measurements,” Scholzen said.
Fall measurements are usually lower than measurements taken around this time of year because fall comes after the peak groundwater pumping season — summer. But in this case, summer hasn’t even started yet and Scholzen’s measurement of this well was only 2 feet higher than last year’s fall measurement.
“We’re all just kind of holding our breaths,” Scholzen said. “And it [the well’s water level] may not go down anymore. It might hold at this, but I don’t know, we’re just starting the pumping season. We’ll see.”
Although that single measurement is by no means an indication of what’s going on in the whole county, it does illustrate how important it is to collect this type of data, especially during this fourth year of drought. And that’s exactly why Butte County has increased their groundwater monitoring. They may not be able to predict future groundwater levels, but if they start getting calls about wells drying up, at least they’ll already have a pretty good idea about what’s going on beneath the county’s surface.
This isn’t the first time Butte County has increased its groundwater monitoring
This is the second year Butte County has increased its groundwater monitoring to monthly during the drought. The county hopes to use the data to help keep an eye on things this year, but also to help understand Butte’s groundwater system for the future. (Groundwater level monitoring was increased in the ’90s in Butte County and those measurements are currently being use to help analyze this drought.)
Be prepared
This year, Butte water officials expect groundwater use to be high and that shallow wells could run into problems. Check out Butte’s Private Well Owner Information Brochure to learn more about Butte County’s groundwater system, to get a well preparedness checklist and to learn what you should do if you’re a Butte County resident and your well runs into problems.
June groundwater measurements happening in other counties too
The Northern Region Office of the Department of Water Resources is also taking extra June groundwater measurements in the valley portions of the other areas it monitors. That includes the counties of Glenn, Colusa and Tehama, and also the area of the Redding Basin.