Green Infrastructure

INCREASED FREQUENCY, MAGNITUDE, DURATION AND LIABILITY OF FLOODS: “A forest’s influence on flooding stems from the many random or ‘chancy’ features in a watershed. And when something is chancy, this requires a deeper understanding of Nature,” stated Dr. Younes Alila, professional engineer and professor in the UBC Faculty of Forestry

October 21, 2025 - Posted in Design With Nature to Create Liveable Communities & Protect Stream Health - an array of contextual resources, Smaller Hydrologic Footprint

Note to Reader:

Published by the Partnership for Water Sustainability in British Columbia, Waterbucket eNews celebrates the leadership of individuals and organizations who are guided by the Living Water Smart vision. Stories are structured in three parts: One-Minute Takeaway, Editor’s Perspective, and the Story Behind the Story.

The edition published on October 21, 2025 is about profiles in courage and is reproduced in part below. It featured two individuals: former BC cabinet minister Mike Morris; and University of BC professor Dr. Younes Alila. The story behind the story is about how they have aligned efforts to build awareness of Dr. Alila’s Flood Risk Methodology for flood protection. Their compelling message is that removal of forest cover, whether in rural or urban watersheds, increases the frequency, magnitude, duration and liability of floods.

Trouble in the Headwaters

In July 2025, the University of BC issued a news release titled Clear-cutting linked to 18-fold rise in extreme floods. This followed release of the gripping 25-minute documentary titled Trouble in the Headwaters the month before. This combination generated extensive media coverage.

The documentary profiles research by Dr. Younes Alila of UBC Forestry that reveals how loss of forest cover has triggered a cycle of flooding, landslides and drought. The two announcement provides context for this edition of Waterbucket eNews.

STORY BEHIND THE STORY: Increased frequency, magnitude, duration and LIABILITY of floods – conversations with Mike Morris and Younes Alila

“The story behind the story is structured in two parts, with 4 topics in each part,” stated Kim Stephens, Waterbucket eNews Editor and Partnership Executive Director.

“In Part One, Mike Morris shares his experience related to risks and liabilities. He brings three perspectives to the topic: RCMP commanding officer; elected member of the legislative assembly and cabinet minister; informed member of the community writ large. He concludes with optimism about what can be if there is a political will.”

“In Part Two, Younes Alila elaborates on his belief that science without passion is not science. He is in the news a lot because he is raising the alarm. Just like Mike Morris, his message boils down to RISK AND LIABILITY. The actual consequences of stripping the landscape of trees, he warns, are magnified in this era of weather extremes.”

PART ONE: What motivates Mike Morris? His experience with risks and liabilities!

“Mike Morris is a former cabinet minister. That sets him apart from someone who just has an opinion about Younes Alila. So, I began our conversation by asking what is the story behind the story of how he became a passionate fan and ally of Younes.”

PART TWO: What motivates Younes Alila? His belief and inspiration that science without passion is not science!

The context for the conversation with Mike Morris and Younes Alila is Clear-cutting linked to 18-fold rise in extreme floods, UBC study finds, a story published by UBC Reports in July 2025. The story generated major news coverage in BC because of its relevance for forest management practices.

A few months later, in October, a new study published in the open access journal Frontiers in Environmental Sciences received global attention as featured in a Science Magazine by a press release titled UBC Study Highlights Importance of Monitoring Flood Frequency for Safeguarding B.C. Communities.

TOPIC 5: A watershed is a system and everything is connected

“The forest owes its power to the landscape features, not to its ability to evapotranspirate. That is the headline,” says Younes Alila with passion in his voice.

“Evapotranspiration is necessary but not sufficient to empower the forest and affect hydrology in general and floods and droughts in particular. This can only be revealed through a probabilistic framework.”

“Our research also highlights the potential for natural asset management which supports the context and ecosystem service based approach to land and natural resource management.”

Cause-effect and the space-time relationship

“Thinking like a system means you do not make decisions at the site scale. It is not about a particular cut block, stream reach or cross-section, or a bridge or a culvert. You need to step back and look at the big picture.”

“You need to look at the entire stream network and what these flows are doing OVER TIME…AND IN THE LANDSCAPE OF THE WATERSHED.”

“It is the modern SCIENCE OF CAUSATION which imposes the probabilistic framework for investigating the causal relationship between the climate and/or land use coverage change.”

An understanding of cumulative effects is foundational

“The cause-effect relationship is the only way to put to the forefront the desperate need for an understanding of cumulative effects. And the desperate need for thinking about the headwaters when we are making decisions downstream.”

“And guess what? That cumulative effect study, investigation or assessment…that UPSTREAM-DOWNSTREAM CONNECTION…can only be investigated through a causal framework.”

“Cause-effect. The climate is the cause. The effect is the hydrological response. The land use, land cover changes are the cause…and the hydrological response is the effect.”

To Learn More:

Waterbucket eNews stories are structured in three parts: One-Minute Takeaway, Editor’s Perspective and Context for Busy Reader, and the Story Behind the Story. To read the complete 3-part storyline, download a PDF copy of Living Water Smart in British Columbia: Increased frequency, magnitude, duration and LIABILITY of floods.

DOWNLOAD A COPY: https://waterbucket.ca/wcp/wp-content/uploads/sites/6/2025/10/PWSBC_Living-Water-Smart_Mike-Morris-on-flood-risk-and-liability_2025.pdf