Little Bow River targeted in flood diversion plan
Foothills: Province studying proposals to move water around High River
Wednesday, Apr 09, 2014 06:00 am
Provincial officials are studying proposals to divert water from the Highwood River around High River to the north or south to protect the community from future floods.
However, members of MD of Foothills council want to ensure the excess floodwater is not sent in one direction to limit potential impacts from the diversion.
The Alberta Flood Recovery Task Force presented details of proposals to divert floodwater around High River to MD council on April 2.
The task force is looking at diverting floodwater into the Tongue Creek upstream of High River. It is also investigating options to take water from the Highwood River from locations west of the town and diverting it to the south, either through the Women’s Coullee or the Little Bow River.
MD Reeve Larry Spilak said the MD prefers using both a north and south diversion to limit the impact on areas where floodwaters will be sent.
“By making the wrong call here you can create a whole lot of havoc down stream,” he said.
It’s not known how much water flowed through High River in last year’s flood because provincial monitoring stations on the river were wiped out, but estimates put this number as high as 1,800 cubic meters per second.
Cathy Maniego, task force executive director resilience and mitigation, said they are aiming to divert enough water from the Highwood River to the west to bring flow rates down closer to a target of 750 CMS.
Maniego said it hasn’t been determined if water will only be diverted one direction, or if it will be split.
“There’s no decisions made at this point,” he said.
Maniego said the only way to make a diversion along either the Little Bow or Women’s Coulee is to do it in conjunction with a dam. The proposed Women’s Coulee diversion would require the construction of a dam southwest of High River, while the Little Bow diversion would require a dam on the river in the southeast corner of the MD.
A third option to divert water to Frank Lake was considered, but Maniego said it would not be viable.
She said there are benefits and drawbacks to all the options. A north diversion would only affect the Highwood River, however, Maniego said a diversion to the south would allow water to be stored and used during a drought.
As well, she said projects that make use of natural channels would cost less to build.
Maniego said they hope to narrow down the list of choices in the next couple weeks before a provincial flood symposium planned for April 29 in Calgary. Once projects have been selected, she said it will take about a year to complete designs and obtain the necessary regulatory approvals.
High River mayor Craig Snodgrass said the diversions will bring the Highwood River in High River down to a level the Town could handle.
“We can handle 750 (CMS),” he said. “We could handle 750 before, what we can’t handle is 1,500.”
MD coun. Rick Percifield agreed with Spilak that floodwater should be diverted to both the north and south.
“Neither river system can handle that much water,” he said.
Percifield questioned whether a dam would be suitable on the Little Bow River.
He said splitting excess floodwater down the Little Bow River with a northern options could eliminate the need to build a dam.
Percifield also said splitting the flow would also allow for a better management of water levels on both the Little Bow River and on Tongue Creek.
Regardless of what options are selected, he said some MD residents will end up being flooded out.
Little Bow area resident Shirley Pickering sending floodwaters down the Little Bow River would affect landowners and residents.
She said the Little Bow River did not flood in 2005, but it was significantly impacted in 2013 when water from the Highwood River ended up flowing into the Little Bow.
“In 2013, the flood through Little Bow was valley-wide pretty much,” she said. “A lot of people were impacted along the Little Bow.”
Pickering said diverting water down the Little Bow could increase the frequency and magnitude of flooding along the normally small watercourse.
She said residents in the area need more information about the proposals.
“We would just like clarification on the process and we want to know what those diversions mean and how they’re being related to the local decisions that are going on,” said Pickering.
Associate Minister Kyle Fawcett said landowners that are affected would be compensated.
“That’s a big component of this… there would be fair compensation,” he said.
While the Province has offered voluntary buyouts to homeowners in floodway areas, Fawcett said it would not likely follow the same process for the flood mitigation projects that are ultimately selected. He said the Province may end up having to expropriate land where it can’t reach an agreement with property owners.