It’s not yet known exactly what will happen to the millions of cubic metres of material dumped in the Mount Meager landslide, along with the debris scraped and scattered by the massive Aug. 6 event. While some officials will be keeping a careful watch for any blockages from woody debris, and continuing to grapple with the issues of gravel management in the valley and dyking for lower Mount Currie lands, they say they aren’t expecting any drastic effects to surface this fall.

“The landslide’s not going to make it rain more. Really, we’ll be watching for increased woody debris and these types of things,” Jeff Westlake, operations manager for the Pemberton Valley Dyking District (PVDD), said last Thursday (Aug. 12).

The landslide led to fears of valley flooding and an evacuation order for about 1,400 residents as a massive lake formed behind a dam at the confluence of Meager and Capricorn creeks. The waters eventually broke through the dam and eroded it gradually, but masses of woody debris were observed sloshing down the Lillooet River through the valley.

Westlake expects there will be a “massive amount” of studies launched in the area, including investigations of debris flow and transportation of sediment, and PVDD officials will seek to learn from a lot of that information. In the meantime, they are “certainly looking at our options” to study how the excess sediment may move into the system, he said.

“We’ll be looking for funding sources to help us monitor how much is coming in and how much we should be taking out,” Westlake said.

Over the years, Westlake said, a significant amount of gravel has been removed from local rivers and creeks. If left alone, accumulating gravel can create channels that could force water to rise over dyke levels.

Gravel “could be a big problem depending on how much sediment you have coming downstream and into the system,” Westlake said. “That’s why we’re in the process of trying to come up with a gravel management plan to really stay on top of it” and manage the issue in a long-term, sustainable fashion, he added.

The PVDD has been working on a long-term gravel management plan for several years, and finished the document in 2007. Dialogue has been ongoing since then with officials at the federal department of Fisheries and Oceans Canada (DFO) to reach agreement on the plan.

However, the effect of the landslide “is going to change things a lot,” Westlake said. It’s too early too tell how much the plan might change, he said, but officials will work over the next few weeks to develop a “work program with what would be required to fine-tune that management plan.”

Come fall, Westlake said he’ll be watching out for blockages from woody debris around bridges when high water is expected. Other than that, he said, he anticipates a pretty standard year.

The evacuation order for residents in Mount Currie also offered a reminder of the vulnerable state of low-lying Lil’wat Nation reserve lands, which remain without a dyking system. The need for dyking “has always been expressed by the nation,” Senior Administrator Mike McGee said, so there’s nothing new there – but the stumbling block has been and remains the money.

Conceptual plans exist for dyking in the area, but it could cost in the neighbourhood of $20 million just to establish protections around the short stretch of the river running through reserve lands, McGee estimated. And the complex task would span several different jurisdictions and require extensive studies and planning.

McGee said Lil’wat Nation officials will continue to pressure governments and all possible sources to protect people and property in the valley once and for all. He’s certain that will be achieved some day, because “there’s no other alternative.”

“We’ve been saying it for years, and we will continue to say it,” he said.

He said his concerns about flooding this fall due to debris working its way through the system have not increased, adding that he believes the branches and logs will work their way naturally through the system.