LOLO – Clark Fork Coalition project manager Jed Whiteley lives a mile away from Lolo Creek and has seen the lower stretch dry up before. The flows can vary from year to year, but this summer is like nothing he’s seen before.
“This year, it bottomed out earlier than it has since we started monitoring. It bottomed out way back in July,” Whiteley said. “We’re looking at a historic low year, and I think the smoke and everything else proves that.”
As part of a water lecture series sponsored by the Clark Fork Coalition, Whiteley led about 20 people to where Lolo Creek flows through Traveler’s Rest State Park. In good years, Lolo Creek is one of the top three sources of cold water for the Bitterroot River. Now barely a trickle as it flowed under the Traveler’s Rest bridge, Lolo Creek provides a glimpse of what could happen to other Montana rivers and creeks if people aren’t aware of their water use and how modifications can impair stream health.
Lolo Creek has two main issues: dewatering and too much sediment. So Whiteley highlighted some of the changes being made and some that are still needed to help Lolo Creek return to the stream observed by Lewis and Clark.
When it comes to dewatering, the last few miles of Lolo Creek east of the railroad are the most telling. There, the stream gets low, hot and sometimes turns to dry cobble by the end of the summer. It’s nothing like the section about 6 miles farther up near the Fort Fizzle Campground where the creek flows are 6 to 7 times greater. The difference is caused mainly by a Maclay Ranch ditch diversion below Fort Fizzle that can pull a majority of the late summer water - 32 cubic feet per second - out of the creek.
Another irrigator farther down, the O-Z Ranch, uses about 20 cfs of water.
Whitely said Lolo Creek is still flowing because the irrigators have been working with him this year to keep a little more water in the stream. But irrigation is not the only thing that causes flows to drop.
Drought is a big player this year. With low winter snowpack, many of Montana’s streams, including the Bitterroot River, are at just a quarter of their normal flow. It’s also caused groundwater levels to drop.
Around Lolo and throughout the Bitterroot Valley and other populated areas of Montana, groundwater has been further depleted by an over-abundance of groundwater wells.
“We’ve seen that, with some people having wells going dry in this lower area where they’ve never had wells go dry,” Whiteley said. “This year, three Lolo municipal wells were tapped out in June when everyone turned their sprinklers on.”
As climate change causes hotter, drier summers, groundwater and surface water will start running short. In many areas, the two work together so when more groundwater is sucked up through wells, less is available to recharge the rivers that are already low to begin with. The main way to prevent that is to cut back on household water use.
The drought in California is a good illustration of the crisis that occurs when farmers and households keep pulling water out of the ground. The surface of the ground is collapsing with no water to fill the void.
In the Bitterroot Valley, it's been bad for trout that need to be able to swim up tributary streams to escape the heat. This year was similar to 2013 when trout weren’t able to migrate up Lolo Creek and some were stranded in shrinking pools. Whiteley said they tried to rescue as many trout as they could last week.
“We got what we could out of the pools, but I’ll bet thousands of fish died, it was drying up so fast,” Whiteley said.
When streams are low, they also heat up faster. July was the hottest month in history, according to the National Oceanographic and Atmospheric Administration, and that was reflected in dangerously high stream temperatures.
Native trout start getting stressed at around 68 degrees and start dying at around 77. Whiteley said Lolo Creek topped out above 80 degrees on several days in June.
More water flowing down the creek would keep the water cooler and keep the creek connected to the river.
“We’re not going to get the water up to where we’d really like it. But if we could add about 10 to 15 cfs of flow, that would add a lot more habitat where the macroinvertebrates live and make the creek more productive,” Whiteley said.
Too much sediment makes it hard for macroinvertebrates to feed and attach to rocks so there are fewer bugs for trout to eat. Native trout, such as endangered bull trout, also need clean water.
The Department of Environmental Quality conducted a study of Lolo Creek in 2003 and found a number of situations that are adding an excessive amount of soil or sediment to the creek. They’re the same problems that many creeks suffer from: straightening, poorly constructed roads and now wildfires.
When U.S. Highway 12 was constructed, about 7 miles of the creek was straightened. Since water is no longer slowed by a meandering streambed, it speeds up as it shoots down the straightened course. That causes the water to have more force so it erodes the banks and cuts down into the stream bottom, carrying the soil away.
In other areas that used to be owned by Plum Creek Timber, old logging roads that parallel the creek were built on steep embankments that are slowly eroding. In addition, old culverts that were too small become plugged with debris, causing water to flow outside the channel.
Fortunately, the Forest Service is preparing to reclaim about 14 miles of those roads.
Finally, the water quality of Lolo Creek is threatened by soil exposed by the 2013 Lolo Fire. So the Clark Fork Coalition and the Lolo Watershed Group are working on grants to re-vegetate the area before a big storm comes along to wash away the topsoil.
Making just a few of these changes could have a big positive effect, said Lolo Watershed Group president Bobby Bartlett.
“We’re trying to get some water quality studies going so we can see what has been accomplished to reduce sediment since the (DEQ study) was done,” Bartlett said.
Enacting change is a slow process, and it will be a few years before any of the changes are complete, said CFC director Kathy Knudsen.
“We know we need more flow and less sediment. The social pieces, regulating hurdles and funding can hold us back but we know what we need to do,” Knudsen said.