How low can the St. Joseph River go?

FOUND: Rusty bicycle frame, thoroughly encrusted with sediment, stones and half of a clamshell because it's been bathing in the St. Joseph River -- until now. Draped with dried river plants. Like artwork. Now exposed to the air for the first time in God-knows-how-many years.

The bike frame sat there on the stones of a riverbank gone dry one recent evening when the day's 100-plus temperatures had finally scaled back.

Across the river, two deer, two turkey, a family of ducks and nine great blue herons and sandhill cranes came to drink and cool off.

Odd things can be seen on the St. Joe these days as a persistent drought drives the river level lower and lower.

Saturday's narrow band of rain boosted the river level just a tiny bit in some parts.

The rain felt generous as it dumped 2.11 inches in South Bend, but, also along the river's route, it left Mishawaka with just a quarter inch, no rain at all in Elkhart, .13 inches in Niles-Buchanan and anywhere from almost 1 to almost 2 inches in the Michigan counties of St. Joseph and Cass, the National Weather Service reports.

The ol' man river still hasn't surpassed its all-time record lows. Not yet. And it's not clear when the river will return to its normal level -- possibly not even by next summer.

The story repeats itself across this area and the Midwest in all kinds of streams and rivers and lakes and in the parched land around them.

The landscape changed dramatically by the Keller Park boat launch in South Bend, where wide and flat riverbanks dried up enough to take a long walk, made a little shorter after Saturday's rain. Recently a man rooted around the shallows for crawfish. The boy with him netted a small catfish. Clams were getting stranded in pools of water.

Everywhere, leafy water plants have flourished more than usual, hogging as much as half of the river's width. Naturalist Evie Kirkwood, who's director of the St. Joseph County Parks, said the excessive heat had spurred that growth.

Those extra plants, like the trees along the banks, soak up water for their own use. Through gauges on the river, scientists can actually see how river levels drop during the day as trees and plants are busy turning sunlight into food through photosynthesis, said Don Arvin, a surface water specialist for the U.S. Geological Survey in Indiana.

This is a hectic time for the USGS. Agencies and companies are checking on drought data so they don't foul the environment, Arvin said. Some power plants use river water for cooling, but they're under strict guidelines. If there's not enough water, he said, they don't want to raise the water temperature so much that they "cook the fish."

The USGS staff also have had to keep moving some gauges in the St. Joe River because the water level kept dipping below them.

Locally, Indiana Michigan Power runs six of the 17 hydroelectric dams on the St. Joseph River, stretching from Constantine, Mich., to Berrien Springs. But, thanks to the low flow, I&M has been generating only 3.5 megawatts of electricity, down from its capacity for 22.5 megawatts, said spokesman David Mayne. That's because only nine out of the 41 turbines can operate, he said.
Don't worry about your electricity going out. I&M counts on the dams for less than 1 percent of its total power, Mayne said.

"A lot of people get the impression that the dams are for controlling the flow of the river -- they're not," he said. "They're for generating electricity."

Federal regulations dictate that the water upstream of a dam has to remain steady at certain levels -- like 750 feet above sea level at Mishawaka's Twin Branch dam, Mayne said. They can't allow any more water to pass through the dam than what comes their way.

Watching for a record

The river hasn't quite hit the record low. But it's getting close.

The USGS measures the amount of water churning through a given point.

On Thursday, the river's flow in Three Rivers was 209 cubic feet per second (cfs), down from 215 cfs the day before. By Monday, it bumped up to 230 cfs. The lowest average daily flow ever recorded in Three Rivers was 78 cfs on Sept. 12, 1964.

But the record lows vary from one gauging station to the next.

In Elkhart, Arvin said, the low was 336 cfs, recorded on Aug. 5, 1964. The current flow is under 800 cfs.

When Arvin put the Elkhart numbers on a graph, you could see -- in general -- that this year's sharp decline in water parallels the drought of 1964, when the river hit those record lows, as well as the 1988 drought, which was severe enough that it's still used as a benchmark.

If you look just at the height on Monday, the river in Niles was at 4.34 feet above a certain point (not the actual depth of the river). That's essentially the same as last week. And it isn't far from the record of 3.95 feet in 1939, said hydrologist Mike Rehbein with the National Weather Service.

The St. Joe is among several rivers that feed Lake Michigan. But the big lake is so, well, big that it hasn't really suffered from drought, said meteorologist Richard Castro with the National Weather Service in the Chicago area.

Lake Michigan is about 8 inches below its level a year ago, he said. It's also 11 inches above the lake's all-time low, recorded in 1964.

What the river needs

Over the next few days, the St. Joe could lose whatever gains it made from Saturday's rain. That isn't definite, but it's the way the river has behaved in the past, Arvin said.

When drought hit the area in the 1930s and 1950s, he said, it took a few years for the river to rise back to its normal levels.

What would it take?

Basically, we need a long, steady rain that stretches itself over several days, said Al Shipe, a hydrologist with the National Weather Service in Indianapolis.

The best chance for that, Rehbein added, is when hurricanes and tropical storms to the south send lots of rain our way.

It won't help much if we get a big storm that lasts just one afternoon. That water, Shipe said, would quickly funnel itself into the river and then dump into Lake Michigan. Then the river level would go back to low.

The rain needs to first soak itself into the parched soils that make up the watershed -- the land that continually drains into and feeds the St. Joseph River.

Shipe offered this "rough guide" to understand how dry the land is:

  • If we received a half inch to 1 inch of rain, it would disappear so fast that "you wouldn't even know it rained."
  • If we got 1 to 3 inches, your boots might get muddy.
  • If 3 inches or more fell, a stream that used to flood would turn into standing water.

For Michiana, Shipe doesn't see any significant rain in the forecast over the next week and a half. We may be on the edge of a rain system that will go to the Ohio River area instead.

For the next three months, he said, there are equal chances that we'll get either rain or more dryness. And it will remain "on the warm side," he said.

Could winter snow replenish the ground when it melts? Hard to tell. You can't talk about inches of snow because some snow has more moisture than other snow, Rehbein said. And snowmelt won't help if the ground is frozen at the time, refusing to absorb.

Nobody is saying that the St. Joe will run completely dry. That ol' man river, it keeps on rollin' along.

Staff writer Joseph Dits:
jdits@sbtinfo.com
574-235-6158