Montana Fish, Wildlife & Parks put an emergency rule in place on Friday, April 11 that closes the Bitterroot River near Corvallis to all floating from Woodside to Tucker Fishing Access Sites due to flow conditions that make portage around the Supply Ditch Diversion Dam very difficult.
The Supply Ditch Diversion, located approximately three miles downstream of Woodside, is a low-head dam built to divert water for irrigation. It creates dangerous currents that have caused several boating accidents over the past several years, including a fatality in 2013.
Ravalli County Search and Rescue has responded to at least two accidents already this year, and the Ravalli County Sheriff’s office supported FWP in establishing the emergency rule.
Signs at upstream access sites and along the river warn boaters to walk their boats (portage) around the dam, but FWP Region 2 Fisheries Manager, Pat Saffel, said that at current water flows, portage is difficult to impossible for many boaters.
“We were hoping to put a rule in place that required boaters to portage around the dam, but when we spent some time on the river this week, we found out that accessing the portage location is very difficult at current river flows,” Saffel said.
This particular diversion has been in place for many years, but it was not much of a concern until the past several years when the river shifted to the East channel of the Bitterroot, forcing boaters to float the channel containing the dam.
Because of their small size, diversion dams often do not appear to be dangerous, especially when viewed from an upstream location, but water pouring over the dam creates a churning current that can hold objects or people under water.
This emergency closure will be lifted once conditions for boat portage around the dam improve. Floating over the dam, Saffel said, is not safe in any conditions.
FWP Region 2 Supervisor, Randy Arnold, said that FWP plans to present a proposal to the Fish & Wildlife Commission this spring that would put a more permanent rule in place for the dam.
FWP will likely consider a rule that would close the Woodside to Tucker stretch of river during spring and early summer high flows when the portage site is extremely difficult to access and then require portage around the dam the rest of the year. FWP also plans to look for long-term solutions for the site that do not involve closures.
“This closure is needed right now in the interest of public safety, but it is not a good long-term solution,” Arnold said.
FWP does not own the dam but is proposing to conduct an assessment of its structure this year to get options and cost estimates for altering the dam to make it safer for boat passage.
“Ultimately, a structural fix would need to be the result of partnerships and fundraising efforts for the project,” Arnold said.
To comment or to be included in notification about the upcoming Commission rule making process, contact Sharon Rose, at FWP, 3201 Spurgin Road, Missoula MT 59804; or email firstname.lastname@example.org.
Saffel adds that rivers are dynamic, especially this time of year, and water levels can change frequently.
“No matter the stretch of river, be on the lookout for obstacles, take it slowly, and when in doubt, stop and scout the water conditions,” Saffel said. “And for some less experienced boaters, it is best to stay off the rivers until spring high water conditions have subsided.”
For more information on the closure, contact FWP at 542-5500.