Shuswap Flooding Analysis
Shuswap flooding and impacts of development & clearcut logging.
by Jim Cooperman
Federal and provincial government staff operate under a gag order that restricts the flow of information to the public. Communication staff manufacture the only information allowed to be disseminated. Consequently, it is difficult for themedia and thus the public to know and understand the factors behind important issues, whether these are disasters such as what recently occurred in the Shuswap or controversial decisions such as the sale of BC Rail.
Below is a column that I recently wrote that was based in part on discussions I had with someone in government who toured the Mara hills by truck and helicopter two days after the flood events. Unfortunately, the column could not go to press because I was unable to provide the source for the information. I do plan to re-write the column in a way that the message can be delivered – which is basically that we can expect more disasters like this one due to climate change and communities must take measures to protect themselves.
Abnormal is the new normal
It was fifteen years ago that the last washout devastated the Mara Lake area, when a debris flood swept down Hummingbird Creek and tore up the highway and parts of Swansea Point. This year the damage is even greater and there were two events, one in Sicamous Creek and the other in Hummingbird and Mara Creeks which join together just above the highway. In 1997, the slide occurred because after 5 days of heavy rain, a poorly designed cutblock channeled too much water into an inappropriately placed culvert that diverted water onto a steep slope, which then gave way into the creek.
It appears that the major cause of this year’s massive flood events was simply inadequate culverts that could not channel the amount of water unleashed by upwards of 80 mm of rain that fell on the remaining snow in the mountains. For the Swansea flood, another obvious factor is clearcut logging, which has been extensive in the watersheds. The loss of forest cover results in a significant increase in the amount of water entering streams (from 5 to 70 percent more water).
When the flow in streams is at a peak flow rate, stream banks tend to erode and often trees can block the creek and when the dam bursts it creates a debris flow slide that can cause major damage. However at Swansea Point, neither of the creeks plugged up as Hummingbird is still scoured from the 1997 event and Mara Creek held up. This time it was the inadequately sized culvert under the highway that plugged and when the water overtopped the highway, it took out the pavement and proceeded to tear up the roads in the residential area and damage houses and cabins.
The Sicamous Creek washout was more of a natural event, as there is much less logging in this watershed, and most of the logging that has occurred was part of the Sicamous Creek research project that includes selective logging and very small blocks. The intense rain generated more water than the culvert under the Skyline Road could handle and the road washed out. The resulting sediment and high flow then joined with the high flow from the other channel and began eroding stream banks along the main stem of the creek. The resulting sediment and debris plugged the highway bridge forcing the flow along with the debris into the Waterways Houseboat property and also to the south into the 2-Mile subdivision.
Compounding the potential for problems such as we are seeing now in the Shuswap is climate change, as the planet warms and as more moisture enters the atmosphere the frequency of severe weather patterns increases. Abnormal has become the new normal, with the increased likelihood of both deluges and droughts, as well as either overly warm or overly cold weather at unexpected times of the year.
Given the predictability of damaging floods and slides in floodplains, one might wonder why governments continue to allow developments to occur. The town of Sicamous approved a massive condo development for Waterways Houseboats for the property now covered in mud and debris in the Sicamous Creek floodplain, despite submissions by local residents warning of the potential for this disaster. Fortunately, the development has not yet been built because if it had been, it would have been thoroughly damaged and damage to the adjacent properties to the south would have been more severe as the concrete walls would have channeled the water to the south.
In the case of Swansea Point, in 2007 the Columbia Shuswap Regional District approved the Hummingbird Resort recreational development despite the likelihood of floodplain problems. However, they did insist on a covenant that acknowledged the property’s potential flood hazard and thus protected the CSRD, the Ministry of Transportation and the province from “claims against them related to damage from the hazard.” Only much appreciated, but now deceased Area C director Ted Bacigalupo voiced any concern, “We cushion ourselves from the legal aspect, but we don’t necessarily provide a safe environment for the people. The risk is still there.”
This year’s flood has become another one for the record books, as lake levels rose to nearly the flood level of 1972. Creeks and rivers were all running at peak levels. Fields that were covered in manure were covered in water, massive amounts of debris and organic matter went into the lake and the potential for another algae bloom is increasing again. When the water finally subsides, the Shuswap definitely needs to find ways to adapt to climate change and installing larger culverts and bridges should be at the top of the list.
Lake water has been extremely compromised as over 50 cars and trucks were in the debris flow and a 20,000-litre gasoline tank tipped over into the water. Many septic systems are also covered now with lake water.
The road is due to be opening soon at 2-Mile, as highways crews are installing a bailey bridge. The channel under the existing bridge is completely filled with rocks and gravel and the creek in flowing in a new channel to the north directly into the bay. Apparently, the plan is to dig out the old channel to put the creek back in to where it was before, but this cannot be done until it is safe to do so.
At Swansea Point, highway crews are working with locals to repair the roads in the residential area. The highway is now open and the existing culvert is back in use, which was the primary cause of this year’s flooding. There was a plan to address this problematic culvert in 2004, as this caption explains:
"Ministers Falcon and Abbott Tour Hummingbird Creek Site - June 3, 2004. Transportation Minister Kevin Falcon and Shuswap MLA George Abbott discuss debris flows at Hummingbird Creek, with Rhona Martin, chair of the Columbia-Shuswap Regional District. Minister Falcon indicated that the province would be prepared to commit $4 million towards construction of a debris basin and bridge south of Sicamous, should a local referendum on operation and maintenance pass."
However, the community was not willing to take responsibility for the operation and maintenance of the proposed bridge and debris basin. They felt that since no other community in the province was forced to take this responsibility that they should not have to either. Thus the bridge was never built and now we have witnessed the consequences. This issue came to the forefront at a public meeting last night, at which government staff from Victoria offered no explanations for the situation, nor could they provide any solutions.
Throughout the region, the flooding has impacted many homes and cabins that were built close to the lake or to other watercourses. Marinas are shut down, boat launches are closed, the marine parks are not open and some roads are underwater, including a portion of Blind Bay Road. Throughout history, flooding has impacted communities, largely because structures and roads are built in areas prone to flooding. It is as if there is a collective amnesia for segments of the population who never seem to remember or respect the forces of nature.
With climate change, it is like nature is on steroids. Consequently does it make sense to allow homes and other structures to be built so close to the lake or in sensitive floodplains? At some point we could even witness another 1894 event, which would result in the flooding of many more homes, businesses and roads. All it would take is another high snow pack and an extremely warm spring, unlike the unseasonably cold springs we have witnessed in the past few years. Will we be ready?
A version of this story will appear in the September 2012 Watershed Sentinel