Lakes on the Frontlines: Climate Change Impacts and the Urgency of Stewardship

About as subtle as a beaver’s tail slap on the water: that’s how in-our-face climate change impacts have been this year. They are impossible to miss when you work on lakes, as we do.

Or, rather, when you’re trying to work on lakes — an emphasis that underscores how extreme the impacts have been. This is what’s on our minds as we mark the second United Nations World Lake Day on August 27. The day was created to raise awareness of the importance of lakes and preserving, conserving, restoring and sustainably managing lake and related ecosystems.

Normally, our summer work includes shoreline surveys of large, important lakes in B.C. and Alberta.

But this year we had to postpone two surveys, an unprecedented occurrence for us in the decade that we’ve been doing these specific standardized shoreline surveys, which are part of the Foreshore Integrated Management Planning program.

How climate change contributed to heavy rains (aka the “June monsoon”) in Alberta

In July, we were supposed to survey Lac La Biche, Alberta’s seventh largest lake.

But, as you’ve likely heard, large portions of Alberta experienced what’s been nicknamed the “June monsoon,” smashing records in many spots for the amount of precipitation received. Lac La Biche was no exception. By the end of June, people reported the lake was up over a metre and they had to keep pulling their docks back.

Those drenching rains in Alberta are being attributed largely to climate change.

As one meteorologist with Environment and Climate Change Canada explained, climate change has created a warmer atmosphere that is able to hold more moisture. That’s then combined with the jet stream breaking down a little bit and not moving the storms on as quickly as they normally do — which might also be caused by climate change, though it does vary from year to year.

The impact for us was that the shoreline had essentially disappeared in many places. That, of course, makes it hard to do a shoreline survey. We had to postpone the survey, with the hope that the water level drops enough that we can complete it in September.

How climate change contributed to long-term drought and wildfires in the Okanagan

In B.C., one of our project lakes, Okanagan Lake, experienced the opposite issue — not enough moisture. As of August 20, the B.C. River Forecast Centre said the lake’s water level is at a record low. The annual cumulative inflow volume for Okanagan Lake was also at a record low.

The low lake levels are due to four consecutive years of cumulative drought, a critically low and early-melting winter snowpack, and severely below-normal spring and summer inflows into the lake. These conditions are unquestionably due to climate change.

The drought means that there is rather more shoreline than usual to survey. Obviously, that doesn’t stop our shoreline survey work.

Drought and wildfire are best friends, though. Drought, in fact, plumped the cushions and filled the larder in the Okanagan, essentially creating the most welcoming conditions possible for wildfire. It lowered humidity. It dried out wetlands, grasses, shrubs and trees, creating a buffet landscape chock full of kindling and fuel. It practically rolled out the red carpet.

All it takes then is a careless human act, a lightning bolt, or some other spark to open the door a crack and wildfire comes whirling in. Quick and voracious in appetite, it can rapidly explode in size.

This is what happened on July 31. A wildfire broke out on Okanagan Indian Band (OKIB) land on the north end of the lake.

The Okanagan Indian Band are friends to our work, and important partners, too. Co-leads, in fact, of what was to be the fourth shoreline survey of Okanagan Lake, a project we were hoping to start in August.

In July, we headed out with two members of their territorial stewardship division to discuss survey methods and calibrate how shoreline features would be recorded. OKIB provided the boat and the two knowledgeable pilots. Our pre-survey reconnaissance mission went well.
That wildfire changed everything.

It consumed 230 structures on OKIB land, devoured forests and burned right down to the shoreline in many cases. We are saddened by this devastating loss for OKIB.

And we postponed that survey, too.

(Incredibly, the lake and its surrounding communities suffered a second, severe blow with the Bald Range wildfire in the Summerland area. Our sympathies go out to the folks who live in this community, too. We still hope to survey this shoreline section next year, as per our original plan.)

The impacts of wildfires on lakes

These wildfires were arguably caused, or at least made worse, by climate change. And the conditions fit perfectly into the category of extreme “fire weather” — the meteorological conditions that cause wildland fires to start, spread or change behaviour. Fire weather in B.C. is now two to four times more likely because of anthropogenic climate change.

These wildfires will have an impact on the lake. In the short term, heavy ash, soot, and charcoal fall directly into the lake. Longer-term, that ash, and any additional ash that might blow or wash into the lake, will add nutrients like nitrogen and phosphorus to the water, which could cause algae blooms. Homes and businesses were also burned, which means the ash can also contain hazardous materials such as heavy metals, asbestos, and hydrocarbons.

If and when the Okanagan does get rain, eroded slopes and hillsides will allow more soil to wash into the lake, clouding the water. The riparian areas that were burned at the shoreline were also important because they help filter runoff that normally ends up in the lake.

In fact, wildfire-adjacent water bodies that are the source of drinking water can remain at risk long after wildfires burn out, according to a UBC-led global review that found water-quality impacts often emerge months or years later — not just immediately after a fire. And Okanagan Lake is a source of drinking water for about 200,000 people.

All of these wildfire contaminants can also present a risk to the fish and other wildlife that live in, on or near the lake.

What people can do to reduce flooding and wildfire impacts on our lakes

People living around lakes, or upstream of lakes, can help in a multitude of ways. Our work, particularly the shoreline surveys, gives land-use planners in the various levels of government the information they need to prioritize and protect valuable shoreline habitat around lakes.

They can protect existing shorelines in natural condition, and they can restore shoreline areas where wildfire or flood damage has occurred or where too much development has taken place by removing manmade structures and replacing it with natural vegetation.

They can encourage or require their citizens, through legislation and bylaws, to prevent fertilizers and pesticides from reaching the lake.

They can also protect the headwaters or watersheds from which lakes draw their water. Again, this means protecting riparian areas around streams and rivers and preventing pollutants from contaminating those water bodies.

As individuals and communities, we are not powerless to protect the lakes that mean so much to us all.