Rainwater Management

ADDRESSING AFFORDABLE HOUSING’S HIDDEN UTILITY COSTS: “Supersizing pipes to accommodate drainage demand is costly and disruptive to communities,” stated Robert Hicks, career engineer-planner in local government in the Metro Vancouver region of British Columbia

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. The edition published on May 28, 2024 featured Robert Hicks, a career engineer-planner in local government in the Metro Vancouver region. He is an original champion of a water balance approach combined with use of green infrastructure to bend the hydrology of a watershed down over decades and thus reduce risk and liability as land use densifies.

Addressing Affordable Housing’s Hidden Utility Costs

A report presented to Metro Vancouver’s regional government in March says leafy, tree-lined neighbourhoods are under threat from increased growth and densification as cities face pressure — including requirements from the provincial government — to build vast amounts of new housing.

The analysis concludes that tree canopy cover has declined and impervious surface levels increased in most member jurisdictions between 2014 and 2020. The region is already backsliding in terms of achieving the regional target to increase tree canopy cover from 32% to 40% by the year 2050.

Removing the tree canopy and covering the land surface with buildings and pavement changes the hydrology of a watershed, and not for the better. How, how much, and how fast water is removed from or runs off an altered landscape is what creates risks and liability.

When tree canopy cover declines and the hardened surface area increases

When we featured Dr. Younes Alila of the UBC Faculty of Forestry last week, his succinct message was: Landscapes and watersheds in BC are at a heightened risk.

With this edition, our spotlight shifts from the rural BC setting to the Metro Vancouver urban region. Hydrology is hydrology. And our land ethic has consequences for water, whether the landscape is urban or wilderness.

Robert Hicks, a career engineer-planner in local government, has an experience-based perspective on the impacts of changes to the landscape. His career achievements include co-creating the “streams and trees component” of the existing Integrated Liquid Waste and Resource Management Plan for the Metro Vancouver region.

EDITOR’S PERSPECTIVE / CONTEXT FOR BUSY READER

“My collaboration with Robert Hicks began in the mid-1990s and continues to this day. So, I have direct knowledge of multiple examples that illustrate why he has consistently been ahead of his time in every sense of that phrase,” stated Kim Stephens, Waterbucket eNews Editor and Partnership Executive Director.

“Robert Hicks is skilled at providing historical context and perspective for “the big picture” of today. He is one of those rare individuals who is able to look back, understand the past and learn from it, and then project far ahead to assess policy implications.”

Streams and trees component of Metro Vancouver regional plan

“Metro Vancouver’s Integrated Liquid Waste and Resource Management Plan has two components, sewage treatment and rainwater (“streams and trees”). It is a regulatory instrument with legal obligations to fulfil. Robert Hicks had a role in the first two plans and held the pen for the 2011 plan update.”

“In the 2011 plan update, my role was chair of the expert advisory Reference Panel. We reported directly to the regional elected representatives. Between 2008 and 2010, we met numerous times with either the Waste Committee or the Finance Committee.”

“The cumulative benefit of the reporting out process was that it informed, educated and enhanced the level of awareness and understanding on the part of elected representatives. This built support for the plan update.”

By design or default, re-development choices and practices bend the hydrology of a watershed, and for either better or worse

“Circa 2000, Robert Hicks created the graphic below as a communication tool to make the case to elected representatives that re-development creates the opportunity for communities to use a water balance approach to bend the hydrology of a watershed over decades. But achieving this desired outcome requires a sustained commitment year after year after year.”

“Robert Hicks was the internal champion at Metro Vancouver for creating the Water Balance Methodology and Model for scenario comparison purposes. Such comparisons were transformational in helping decision makers visualize HOW their municipalities could meet watershed targets and mitigate population growth and climate change, one property at a time.”

“This built support for changes in development practices and galvanized action in the 2000s. The evolution of technical understanding is illustrated by the timeline and milestones listed in the image below.”

“Unfortunately, memories are short and knowledge is either forgotten, lost or ignored as the players change. And so, momentum is dissipated and backsliding sets in. Consequently, the legacy of the past two decades is cumulative impacts rather than cumulative benefits,” concluded Kim Stephens.

STORY BEHIND THE STORY: Bend the watershed hydrology to reduce risk and liability – extracts from conversations with Robert Hicks

The “story behind the story” weaves quotable quotes into a storyline. Insights from conversational interviews with Robert Hicks are structured in three parts. Part One provides the reader with a point of departure. Part Two is an historical flashback. It provides context for Part Three which is contemporaneous perspective.

Part Two complements previous editions of Waterbucket eNews which featured interviews with key players in the history of green infrastructure innovation in Metro Vancouver, namely: Susan Haid, Joan Sawicki, Dale Wall, Hugh Fraser, Richard Boase, and Ray Fung. These stories are extracted from a legacy resource that the Partnership will release later in 2024.

PART ONE: How water reaches streams

“There are three pathways by which rainwater eventually reaches a stream or receiving water. In the urban and suburban settings, land planners and drainage engineers have historically ignored or overlooked two of the three, namely interflow and groundwater,” explains Robert Hicks.

“When you remove tree cover and pave over pervious surfaces so that they are hard, you effectively double the volume of runoff water to be managed and it drains faster. There are also two other consequences.”

“No longer can you sustain minimum flow requirements in streams. And no longer can you recharge groundwater. This is the orphaned resource. It has just been so easy to overlook groundwater historically.”

PART TWO: Genesis of the “streams and trees” way of thinking about rainwater management

“In 1997, incoming CAO Johnny Carline inherited this behemoth of a plan from outgoing CAO Ben Marr. And I do believe that it should be described as a behemoth of a plan,” recalls Robert Hicks.

“Metro Vancouver produced a set of six tomes. Some were biblical in terms of their size. They summarized all the research and work that went into the region’s first Integrated Liquid Waste and Resource Management Plan. It ping-ponged between the Board and the Minister of Environment for several years. Finally, in 2001 the minister approved the plan.”

“Back in the day, it was presumed that everything from before continued and was automatically embedded in the first plan update. But the 2011 plan actually replaced the 2001 plan. Decades later, that foundational research is lost in the Metro Vancouver archives and who knows that it exists.”

There was a clear consensus that land development practices had to change for the better

“Metro Vancouver established an interagency Stormwater Management Technical Advisory Task Group in 1997. It had federal and provincial representatives who advocated for a new business as usual regarding downstream flooding of agricultural lands and fish habitat preservation.”

“At the time, the value of managing drainage on a watershed basis within a broad framework of land management and ecosystem planning was not yet apparent. Research on stream health by Rich Horner and Chris May at the University of Washington changed all this.”

“It became clear that engineering solutions alone would not result in good stormwater management and environmental protection, nor address regulatory infraction risk.”

“What was clear from those early meetings was that the status quo that had been used for drainage and stormwater management in the 1980s and 1990s was unacceptable. The priorities were hydrology and riparian forest canopy. And so, there was tension and the need to find some kind of path forward. My memory of those meetings is that you could cut the tension with a knife.”

“What we saw was, things will get worse if we do not change our ways. And when we showed the picture to the Board members, they agreed that things had to change.”

The path forward takes shape:

“Once we got into implementation, all the pieces started to fall into place…the concept for Integrated Stormwater Management Plans aka ISMPs, the source control concept for capturing and infiltrating rainwater runoff, and the water balance approach.”

“When the process for plan updating commenced in 2008, Metro Vancouver staff were enthusiastic about the role of the Reference Panel. Because there was trust with staff, and the Reference Panel had the attention of the politicians, the Reference Panel could say what staff could not. There was huge positive value in that.”

Capture rain where it falls: “You can bend the hydrology of a watershed over decades just because of the housing redevelopment cycle. But you get just one chance every 50 years to get it right. The Reference Panel reinforced that desired outcome with its recommendations.”

“Metro Vancouver had the budget to fund the early work on the Water Balance Methodology and thus bridge the source control information gap. What we learned from the 50-year scenario comparisons became a foundation piece for Stormwater Planning: A Guidebook for British Columbia.”

Applied research built the case for the New Business As Usual

With the support of SILG, the Stormwater Interagency Liaison Group, Metro Vancouver assessed the Water Balance Methodology on urban watersheds in 3 Metro Vancouver municipalities. Simulation of watershed retrofit scenarios demonstrated that it is achievable to improve and potentially restore watershed health over a 50-year timeline by capturing rain where it falls on the ground. The research answered the question, why must we do it.

Image Source: Report on Effectiveness of Stormwater Source Control, 2002
https://waterbucket.ca/gi/wp-content/uploads/sites/4/2023/11/GVRD-Source-Control-Report-Dec-2002.pdf

PART THREE: Ignored and undervalued, groundwater is the orphaned resource

“The long-term trend climate trend in BC is for warmer winters and longer summers. This means that snowpack on the mountains, which is our traditional source of water supply, is not going to be there or there will be less of it.”

“So, where else do we have natural storage of water? It is groundwater! This is a very narrow, anthropocentric urban perspective that I am taking on this. But it is really critical for urban communities. And this is the context of the lens that I am thinking about for groundwater.”

Deep excavations have consequences for the water balance

“When you go down four, five and six levels of underground excavation for high-rise building foundations, you are intercepting and dewatering the groundwater resource.”

“One face is that you are creating a drainage demand by preventing rainwater from reaching building foundations or removing groundwater at depth. But the other face is the lost opportunity because the water resource is not being managed in either a coordinated or holistic manner.”

“Creating a drainage demand is the more immediate consequence of land use intensification that is driven by very high-density transit-oriented redevelopment. The loss of groundwater as an option for water supply is a future reckoning.”

Challenges implicit in servicing affordable housing with affordable infrastructure

“The Province has come out with their transit-oriented development legislation. What that means is redevelopment. And redevelopment means a demand on utilities.”

“Sometimes these demands have already been anticipated and planned for. And sometimes these are new and somehow have to be accommodated. Sewage and drainage are a little trickier than other utilities. That is where we have this crunch of priorities.”

“Yes, we need affordable housing. How do we make this happen? Zoning is a big part of it. But affordable housing must be serviced with infrastructure that is also affordable. I am talking about utilities like water, sewage, drainage, electricity and roads.”

“The sewer and drainage part is actually a concern. For locations which are basically single family with moderate imperviousness, redeveloping to high density, high imperviousness will create more drainage. Is there enough capacity in the system? Probably not.”

“So, this capacity challenge then rolls into why Green Infrastructure…as a way to service growth and minimize risk…is valid for high density urban redevelopment.”

“This is the same approach that would be used for a stream in a suburban setting. You have to manage water volume if you want to restore the water balance.”

Restoring water balance through green infrastructure has a huge asset management benefit

“When I think back to writing the 2011 Integrated Liquid Waste and Resource Management Plan, I should have been more on top of Green Infrastructure as an asset management solution in the highly urban setting. I did not dismiss it but I did not push it.”

“Circa 2000 when I started to look at Green Infrastructure and embrace it, I felt that it had an excellent fit with protecting urban streams or stream and watershed health in general. And that belief was based on the research work by Richard Horner and Chris May coming out of the University of Washington and validated at UBC.”

“This is great, I thought. Green Infrastructure will help make things better. But I was somewhat skeptical about application in places like Vancouver which has an urban fabric. After all, what open channels are there in Vancouver?”

“Because I was fixated on that ecological stream health relationship, I overlooked the obvious. And that is, by managing the hydrograph using a water balance approach to bend the hydrology curve down, there is a huge asset management benefit.”

“By knocking the peak off the hydrograph, for example, existing investments in infrastructure can be stretched out longer. This would be more affordable than super-sizing drainage pipes. And it could also provide resiliency for climate change with the increasing rainfall intensity!”

“Because I had been a bit skeptical, I find it humbling to admit that I now see Green Infrastructure as actually having a good fit in affordable utility delivery.”

“Even if we want to do the conventional thing and upsize pipes, that is a huge disruption to communities never mind all the costs associated with doing the actual work.”

“That is part that we seldom talk about in engineering. And that is, the disruption to residents and businesses when we upsize infrastructure. They might have another 50 to 100 years of life left in drainage infrastructure if we just bent the watershed hydrology.”

“It is important to say that Green Infrastructure has a fit for both the high-density urban setting and moderately impervious suburban watersheds. In either situation, you must manage rainwater runoff volume on-site,” concludes Robert Hicks.

Living Water Smart in British Columbia Series

To download a copy of the foregoing resource as a PDF document for your records and/or sharing, click on Living Water Smart in British Columbia: Bend the watershed hydrology to reduce risk and liability. It includes a Bonus Feature – the complete interview with Robert Hicks.