As we wrap up June, southern Alberta anglers have experienced a rollercoaster of conditions. Early summer hatches were in full swing, but mid-month brought torrential rains that briefly blew out many rivers. Now, as water levels recede, the Bow River is cleaning up nicely and trout are feeding aggressively again – especially with stonefly season upon us. Below we recap how June fished on the Lower Bow River (Calgary to Carseland) and provide an update on foothills streams in southern Alberta (Highwood, Sheep, Oldman, etc.), which remain elevated and colored from the mid-June rain/snow event.

June started with spring runoff raising the Bow’s flow, but initially it wasn’t as severe or dirty as some years. The river rose from roughly 70 m³/s in early May to around 225 m³/s by mid-June , yet clarity remained decent through these gradual increases. In fact, thanks to a lower mountain snowpack this year, the Bow “never really got high & dirty like years past” during early runoff . Anglers enjoyed consistent fishing on many days despite fluctuating flows – trout were still feeding and could be caught on streamers, nymphs, and even dries whenever the water had a bit of stability . High water often pushed fish tight to the banks, where they remained willing to chase flies presented along the edges .


Everything changed around June 21–22, when a torrential rain storm dumped enormous moisture on the region. Up to 100 mm of rain fell around Calgary with nearly double that in the foothills to the west . This rain-on-snow event in the foothills (where ~10–20 cm of late spring snow also fell at higher elevations) caused a sudden high-water event on the Bow and its tributaries . The Elbow River (which joins the Bow in Calgary) rose rapidly, carrying loads of mud and turning the lower Bow into a chocolate-colored torrent. It appears the foothills snowpack sitting on loose soil contributed to the turbidity – as that snow rapidly melted under heavy rain, it likely picked up tons of sediment. (Such rain-on-snow events are known to cause significant soil erosion and sediment runoff .) In this case the Bow’s downstream tributaries like the Elbow delivered the mud; areas upstream in the mountains got far less precipitation and stayed clearer. The result was a blown-out Bow River from Calgary through Carseland for several days. Many guide trips were canceled for safety and poor visibility, and anglers had to wait it out until flows crested and began to fall.


By the final week of June, the Bow River has stabilized and is recovering quickly. Flows are dropping back toward seasonal levels and water clarity is improving each day. With the river “getting back to normal,” the fishing has bounced back nicely. In fact, lots of bugs were already around during the high water (caddis, mayflies, stoneflies) just waiting for a break in the flows – now the trout can finally see them again! Golden Stoneflies, in particular, are the headline hatch right now. These large summer stoneflies have been popping on the lower Bow for some time, and their emergence is progressing upstream into Calgary . Trout that hunkered down through the muddy spell are now gorging on stoneflies as the hatch intensifies. Anglers are reporting more fish looking up for big dries, especially in sections downstream of the city where the hatch started earlier. Smaller hatches of caddis and PMDs (pale morning duns) are still ongoing each day, but those take a backseat to the big Stoneflies for the moment – the trout know a hefty stonefly is a more filling meal. Early morning and late evening tend to be peak time for stonefly activity (when the adults skitter and lay eggs) , so plan to fish the cool hours if you’re targeting that dry-fly action. During midday, you may see fewer rises, but come late afternoon caddis and PMDs will spur rising fish again near riffles and banks .


For tactics, June’s turbulence reinforced a few lessons. When flows were high and off-color, streamer fishing was the ticket to find aggressive trout hugging the banks. Large, dark streamers (black, olive or brown) produced some terrific fish even in the dirtiest water . Many Bow anglers threw double-streamer setups – for example, a flashy baitfish pattern trailed by a darker bugger or leech – to maximize attraction in the murk . Now that clarity is improving, streamer bites can be more hit-or-miss, but don’t be afraid to keep tossing them, especially under cloud cover. As levels fall, fish will start moving out of the flooded shorelines into riffles and seams again . So, shift your focus back to those spots where sediment is clearing and fish can ambush food.


Dry flies are back in play too. With caddis and mayflies hatching daily, fish are rising most consistently in the afternoons and evenings once the water warms a bit . A tandem dry fly rig can be very effective – for instance, a bushy stonefly or grasshopper pattern as an indicator, with a smaller caddis or PMD dry/emerger tied behind. This covers both the “big bite” and the smaller naturals. If fish are visibly up for stoneflies, you can also skip the dropper and throw a single high-floating foam stonefly imitation. Patterns like Stimulators, Chubby Chernobyls or other golden stone dries are great choices. Just use a stout leader (2X or 3X) to turn over those big bugs and handle fierce strikes. When trout seem picky, downsize to a low-riding stonefly pattern or even try an egg-laying female imitation skittered on the surface – sometimes a subtler presentation draws more eats from pressured fish .


Finally, nymphing remains a reliable fallback on the Bow, especially as it transitions out of runoff. In high water, a big stonefly nymph or dark leech with plenty of weight was crucial to get down in the fast, deep flows . Post-spike, you can lighten up a bit, but you still want to dredge the runs and drop-offs where fish hang mid-column. Fish the “walking pace” water – medium-speed riffles and seams, and adjust your weight/tippet until your flies occasionally tick bottom . Productive nymphs lately include stonefly patterns (Pat’s Rubber Legs, Jimmy Legs, etc.), large prince nymphs, and caddis pupa imitations. With water clarity improving to a few feet, even size 14–16 mayfly nymphs (PMD, pheasant tails) can start to work again for picky feeders.


All in all, June on the Bow tested anglers with big flow swings, but the river is shaping up for excellent summer fishing. The quick surge of runoff helped flush out silt and refresh the system without causing major flood damage – a silver lining. Now we have healthy flows, cooling water, and abundant hatches heading into July. Make sure to check the daily flow rates (as dam releases and weather can change conditions overnight) and approach the river with some flexibility . One day the fish might still hug the banks; the next they could be back in mid-river riffles. By staying adaptable with your flies and tactics, you’ll capitalize on the Bow’s improving conditions. The stage is set for the stonefly extravaganza to continue, backed by caddis at dusk and morning mayfly spinner falls – truly a fun time to fish the Bow!

When the Bow River Rose:

The Flood That Changed a Fishery Calm Before the Storm In mid-June 2013, the Bow River flowed cold and clear through southern Alberta, unsuspecting of the fury that was about to unfold. Snow still clung to the Rocky Mountain peaks; an unusually deep late-season snowpack remained in the high country due to a cool spring and even a late May snowstorm . The day before the flood, river flow levels were unremarkable – around a few hundred cubic metres per second, typical for early summer. Fly fishermen wading the Bow’s gentle runs had no idea that within 48 hours, their beloved river would transform into a raging torrent. It was the calm before a historic storm, with Mother Nature quietly assembling the perfect conditions for disaster: waterlogged ground, lingering mountain snow, and a weather system poised to deliver a deluge. 

The Perfect Storm:

Rain on SnowOn June 19, 2013, dark clouds unleashed a meteorological onslaught over southern Alberta. A stationary high-pressure system to the north forced a moist Pacific low to dump relentless rain on the eastern slopes of the Rockies . In just two days, over 200 mm of rain fell across a vast area – nearly an entire year’s worth of precipitation for this semi-arid region. Some places saw astonishing totals: the town of Canmore recorded 220 mm in 36 hours, and a weather station near High River measured 325 mm in less than 48 hours . Importantly, this wasn’t just rain running off bare ground – it was rain falling on snow. The warm downpour melted the alpine snowpack, turning snow into liquid and multiplying the runoff. The normally thirsty soil was already saturated from prior spring storms, so almost every drop of this rainfall (and melted snow) rushed directly into creeks and rivers. Heavy snow loads remained in the Front Range mountains, so the rain-on-snow effect supercharged the floodwaters . Small mountain streams became brown, boiling rapids overnight. By June 20, tributaries like the Kananaskis, Ghost, Highwood, Sheep, and Elbow were all spilling over their banks . The stage was set for the Bow River – Calgary’s blue-ribbon trout stream – to receive the largest inflow in recorded memory.

Bow River Unleashed:

As the rain pounded down, the Bow River swelled at a rate that defied belief. On the morning of June 20, what had been a fairly placid flow turned into a surging wall of water. In less than 12 hours, the Bow at Calgary rose from roughly 200 m³/s to well over 1,000 m³/s and kept climbing . By the night of June 20, the river had burst over its banks, forcing emergency actions across the region. Authorities issued flood warnings and activated emergency plans as the water raced toward Calgary . On June 21, the Bow River reached its peak flow through the city, gushing at approximately 2,400 m³/s – about eight times its normal rate . (For comparison, this was roughly triple the peak flow of a large 2005 flood a few years prior.) The smaller Elbow River, joining the Bow in downtown Calgary, also exploded to 1,240 m³/s (twelve times its usual flow) , adding to the inundation. Together, these rivers turned low-lying parts of the city into a temporary lake.
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City streets became canals as the Bow River roared through neighbourhoods. Around 80,000 people were urgently evacuated from their homes in Calgary alone , and dozens of communities throughout southern Alberta declared states of emergency . Bridges were overtopped or washed out; power outages plunged parts of the city into darkness. The normally sedate Bow, beloved by anglers for its clear flows, had become a churning, chocolate-brown monster carrying trees, debris, and even pieces of houses in its current. Eyewitnesses along the banks on June 21 described the river as “unrecognizable” – an alien force of nature surging past downtown. At its peak, the Bow ran higher than anyone had seen in several generations, exceeding any flood since 1897 . It was truly a once-in-a-century event, the largest flood in Calgary’s modern history with water levels nearing those of legendary floods from the late 1800s .


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A Region Forever Changed

When the floodwaters finally began to recede after June 22, they left behind a trail of destruction and a landscape forever altered. The 2013 flood was the most costly natural disaster in Canadian history at the time, causing an estimated $5–6 billion in damages across southern Alberta . Whole towns like High River were underwater. In Calgary, 26 neighborhoods were badly flooded . Streets and parks were buried in silt and debris; familiar landmarks were damaged or gone. Tragically, five people lost their lives to the flooding . For those who experienced it, the flood was a life-altering event, a moment when nature’s power humbled an entire region.
For the Bow River itself, the flood was a geomorphic reset. The river scoured its banks and bed with immense force, eroding away entire sections of riverbank and redistributing thousands of tonnes of gravel and sand. Long-time anglers returned to find that their favorite back eddies and side channels simply no longer existed. The river’s architecture was significantly changed – channels shifted, islands and gravel bars moved or disappeared . In Calgary’s iconic Bow River reach, some deep fishing holes were filled in by sediment, while new deep pools were carved elsewhere by the raging current. Tree-lined banks were stripped bare in places, while in other spots the flood deposited new logjams and timber. The Bow’s confluence with smaller tributaries like Fish Creek and the Highwood was completely reshaped by walls of water and debris. It was as if the river had torn up its old blueprint and drawn a new map overnight.

Importantly, not all of these changes were negative for the river’s ecology. While it was heart-wrenching to see beloved river spots altered, floods are a natural process of renewal. Biologists noted that floodwaters, despite wreaking havoc, also created new habitats – for instance, the river carved out fresh side channels and ponds that could become nurseries for juvenile fish . “The changes are all part of the natural process of the river’s own maintenance,” observed Lesley Peterson, a Trout Unlimited biologist, in the months after the deluge . Floods, though destructive, rejuvenate rivers by flushing out accumulated silt, redistributing nutrients, and creating dynamic new environments. In many ways, the Bow River in 2013 was behaving as it always has over centuries – bursting its seams, then gradually healing and finding a new equilibrium. But how would the river’s famous trout fishery fare in the wake of such a cataclysm?



Under the raging floodwaters, the Bow River’s trout were in for the fight of their lives. This river is home to wild populations of brown and rainbow trout (a world-class sport fishery), and these fish had never experienced flows of this magnitude. As the currents sped up and the river volume multiplied, many fish were swept far downstream or into areas they’d never ventured. Some trout likely didn’t survive the violent ride; others were left stranded in atypical places as waters receded. In the days following the flood, observers found live trout flopping in isolated pools and puddles on what had been dry land – side channels and even farmer’s fields that the Bow had temporarily overtaken. The situation looked dire for the fishery. Anecdotal reports suggested a sharp drop in trout numbers, especially rainbow trout, which seemed hardest hit by the flood’s impacts . Rainbows spawn in spring, so the timing was unfortunate – many young rainbow fry may have been simply washed away. Brown trout, which spawn in fall and tend to be a bit larger/older by spring, were thought to have fared slightly better, but they too were displaced and stressed. Long-time fishing guides noted that immediately after the flood, catching trout – especially rainbows – became noticeably more difficult, fueling concern that the Bow’s prized fish population had been decimated.

Yet even amidst this turmoil, there were stories of hope and heroism. As soon as it was safe to approach the river, volunteer crews led by Trout Unlimited Canada (and supported by Alberta biologists and countless local anglers) mobilized for fish rescue operations. They trudged through mud and debris along the Bow’s floodplain, netting stranded trout from residual ponds and channels. Over the week after the flood, these volunteers rescued thousands of fish that would have perished in isolation had they not been returned to the main river . It was an inspiring sight: lines of volunteers passing buckets of wriggling trout, releasing them back into the Bow’s flowing sections. Each rescued fish was a small victory, a sign that the community was determined to help the river recover. “It was heartbreaking and heartwarming at the same time,” one volunteer recounted – heartbreaking to see fish in distress, but heartwarming to see so many people come to their aid. More than 5,000 trout were saved in these efforts , including some trophy-sized browns that had been caught in side ponds. This collective action showed the deep connection Calgarians and Albertans have with the Bow River and its trout – in its darkest hour, they rallied to give back to the river that had given them so much joy.


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Resilience and Recovery:

In the weeks and months after the flood, fisheries biologists kept a close eye on the Bow. They knew that trout populations might take time to rebound, but they were cautiously optimistic. After all, this wasn’t the Bow’s first flood – in 2005, a significant (though smaller) flood hit the river, and data showed that trout numbers bounced back within two years . Rivers and fish are often more resilient than we expect. True to form, by the summer of 2014 there were encouraging signs. Anglers were still catching trout in the Bow, and while catches were lower in some spots, the fish that were caught appeared healthy. Biologists conducting electrofishing surveys observed plenty of young-of-the-year trout in the shallows, indicating that rainbow and brown trout had successfully spawned after the flood and new generations were on the way. In fact, long-term datasets later showed that juvenile trout remained consistently abundant even after 2013 – it was mainly the larger, older trout that had declined in numbers . This meant the building blocks for recovery (the young fish) were in place, as long as they could grow and survive to adulthood.
Over the next few years, the Bow River fishery showed remarkable resilience. Anglers reported that brown trout – which had been almost “unicorns” (rare) immediately after the flood – started to make a strong comeback by 2015 and 2016. Some even noted an increase in large browns, possibly because those hardy fish found refuges during the flood and then had less competition afterward. Rainbow trout numbers, on the other hand, remained a concern. A later scientific analysis confirmed a worrying long-term decline in Bow River rainbows (nearly 50% drop in adult population between 2003 and 2013) . The flood likely contributed to this decline, but it wasn’t the sole factor – other stressors like angling pressure, water management, and the emergence of whirling disease in 2016 also affected the rainbow trout . In response, Alberta’s government and stakeholders launched recovery initiatives, including stricter fishing regulations (the Bow went to catch-and-release only for trout in 2017) and research into cumulative effects on the fishery . These efforts aim to ensure the Bow’s trout have the best chance to thrive in the long run.
Meanwhile, the river itself has healed impressively. The Bow gradually retreated to its pre-flood clarity and flow patterns, albeit in its newly altered channels. Within a year, vegetation started reclaiming the scoured banks; grasses and willows sprouted in the fresh silt deposits, stabilizing the shoreline. Aquatic insects – the mayflies, caddis, and stoneflies so crucial to a trout’s diet – recolonized the gravel beds, and robust hatches resumed, providing a buffet for hungry fish. By 2014 and 2015, anglers could once again witness the evening spectacle of rising trout sipping bugs off the surface. The Bow River, though changed, was very much alive. In fact, some aspects of the fishing even improved: certain runs that had previously been shallow became deeper and more hospitable to fish, yielding surprising new “hot spots” for catching trout. “With the changes in the river, it’s a good opportunity to discover new places to fish along the Bow,” Peterson noted, emphasizing the river’s natural dynamism . Fly-fishers had to adapt to the Bow’s new layout – learning the redesigned riffles, pools, and eddies – but that challenge brought a sense of discovery. The unpredictability of a river is part of its appeal, after all. As Peterson said, “Rivers are naturally dynamic, so to be a good angler you have to work with the river. You can’t expect things to stay the same” . The Bow’s 2013 flood was a dramatic lesson in this truth.

The Bow River Today: A Testament to ResilienceIt’s now been years since that epic flood, and the Bow River has reclaimed its status as one of the world’s great trout streams. If you visit the Bow today, you might hardly guess the violence that once tore through it – except, perhaps, for a newly cut side channel here, or a bank of younger trees there that replaced ones swept away. The river’s trout populations have stabilized and even shown signs of increase in some stretches. Surveys in the downtown Calgary reach still find on the order of 2,500 trout per mile – an astonishing density for an urban river . In the Bow’s classic blue-ribbon section (stretching downstream of Calgary through the prairies), anglers continue to land plump brown trout over 20 inches and feisty rainbows that leap clear of the water. The fish bear a few scars of their trials – one can occasionally spot a healed hook scar on a big rainbow’s jaw, a testament to it having been caught and released multiple times in its life – but they are thriving and wild, descendants of the survivors of 2013. These trout have proven their resilience through floods, droughts, and disease outbreaks. They endure, as long as we safeguard their habitat.
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The legacy of the 2013 flood on the Bow River is twofold. On one hand, it was a sobering reminder of nature’s power, illustrating how quickly decades of human structures (and even some ecological balances) can be upended. It prompted massive investments in flood mitigation and river management to protect communities – new berms, higher dams, floodplains returned to nature – all in hopes of coexisting more safely with the river’s moods. But on the other hand, the flood also highlighted the remarkable resilience of natural systems. Within the chaos was a renewal: the Bow River cleansed and revitalized itself in many ways. Anglers who read the river’s currents today find a mosaic of habitats that likely benefit the ecosystem: deeper holes for fish to hide in during hot summers, newly deposited gravel beds that create spawning grounds for trout and mountain whitefish, and log structures that provide cover. The Bow’s trout, for their part, adapted to the post-flood river and carried on – feeding, growing, spawning the next generation. By 2018, biologists noted strong numbers of young trout, indicating the fishery was replenishing itself despite the setback . Ongoing studies are addressing the remaining challenges (such as ensuring enough big fish survive to older ages), but the river today is still rich with life.

Perhaps most importantly, the 2013 flood instilled a deeper appreciation in the people who know the Bow River. Every time a fly-fisherman steps into the Bow now, there’s a quiet awareness of what the river went through – and a sense of respect. The flood of 2013 made people fall in love with the Bow all over again, in a more profound way: not just as a trout playground, but as a powerful living entity with cycles of wrath and renewal. Anglers swap stories of how their favorite spot “used to be over there before the flood,” then note how they discovered an even better spot later on. There’s a reverence for those trout that survived the flood, and for the river that has carried on.

In the end, the Bow River flood of 2013 was a story of loss and destruction, but also a story of resilience and hope. It changed the river forever – and yet the spirit of the Bow remains. The wild trout still rise eagerly to a well-presented fly on a summer evening, against the backdrop of Calgary’s skyline and the Rocky Mountain sunset. Those trout are living proof that nature can recover when given a chance. As anglers, conservationists, and residents, we are humbled by how quickly things can change, but also encouraged by how well the Bow River has healed. The events of that June will never be forgotten by those who witnessed them. Yet today, when you stand by the Bow and cast your line, you can once again feel that familiar pulse of a healthy river, a river that, despite everything, continues to flow strong and clear, nourishing life and memories for generations to come.

Sources: The factual information and data in this story are supported by official reports and expert observations. Heavy rainfall (200–350 mm) on June 19–21, 2013 combined with alpine snowmelt to trigger the flood . The Bow River’s flow through Calgary peaked around 2,400 m³/s (eight times normal) during the flood , leading to the evacuation of roughly 80,000 people . The flood was the largest since 1897 and caused an estimated $6 billion in damage across southern Alberta . Biologists note that the flood significantly altered river habitat, scouring some areas and creating new ones, but overall fish habitat effects were not entirely negative . Trout Unlimited volunteers rescued thousands of stranded fish from pools as waters receded . Evidence suggests rainbow trout were hit hardest by the flood , though previous floods (like 2005) saw trout populations rebound within a couple of years . In the aftermath, the Bow River remains a productive fishery with about 2,500 trout per mile in the Calgary stretch and a dynamic, resilient ecosystem . The Bow River’s story exemplifies how a wild river and its inhabitants can recover and even thrive after an extreme disturbance, given time and wise stewardship.  

Photo : The Scotiabank Saddledome and surrounding areas in Calgary are submerged by floodwaters on June 21, 2013. Stuart Dryden/Postmedia file