Raingardens by Deborah Jones


Deborah Jones’ interest in “Rain Gardens” began when she semi-tired in 2004 and had time to join the Cougar Creek Streamkeepers with her husband. A request for them to initiate and coordinate a rain garden at an elementary school in 2006 blossomed into a passion for educating others while getting “down and dirty” to help other schools develop their own projects.  Cougar Creek is North Delta’s most productive salmon stream but an overhead map showed that many Vancouver area creeks are sadly now dead.

So why are rain gardens so important? 

It is hard to believe that only a tiny percentage of the earth’s total water is accessible fresh water – yet that tiny percent sustains 9 billion humans plus all other terrestrial and freshwater life!  Deborah reviewed the water cycle which is driven by solar energy and is constantly re-distributing fresh water around the earth. Quite a few of us remembered learning about this in school!

Nature’s stormwater (rainwater) management system is slow and steady. The ground acts like a sponge, soaking up the rain.  Once in the ground, water may be taken up by plants or may continue seeping underground till it eventually emerges in a stream, river, lake or spring, and eventually the ocean.

Evapotranspiration from vegetation, especially trees, has a cooling effect on surrounding areas, and also helps form new clouds that spread moisture farther inland.

As we develop land – whether it’s through logging, farming, suburban or urban uses – we reduce its ability to soak up rainwater; instead, it “runs off”.  Even farmed land has roofs that produce runoff, and areas so trampled by livestock that water can no longer soak into the ground. Cities, with their extensive roofs and paved areas, produce huge volumes of runoff.  The urban heat island effect is made worse by reduced evapotranspiration due to reduced green spaces.

Deborah gave the example of Brentwood mall, which receives 216,000,000 litres of rain a year (yes, millions of litres!) – most of which just goes down drains!  This water travels through pipes that empty, unfiltered, into natural waterways (probably: Still Creek, Brunette River, Fraser River, Salish Sea). She also talked about how new developments have an even greater abundance of roofs, asphalt, sidewalks, and curbs.   The building of underground parking and in-ground basements means that the city expansion goes deep into the ground as well! We are excavating and trucking away our soil, which is nature’s free reservoir for holding water.  Earth’s soil holds more water than all the rivers in the world!

Piped drainage also creates problems. Whether or not the drains are marked with the cautionary “yellow fish”, all drains connect to a network that empties into fish habitats.  When an abundance of rain falls, storm sewers may not have large enough pipes so they are quickly over capacity. The resulting torrential flow causes stream bank failures.  Rain rushes to ocean instead of soaking into the ground. Trees end up suffering from drought and ponds dry up. Young Coho salmon need to spend a full year in ponds! Our climate change is yet another layer adding to the problem, with more intense rain events and longer dry spells.

In addition to the quantity of water being compromised, the quality of the water is a major concern as well.  With no filtration through the soil, pollutants and litter from the street are washed directly through storm drains and into fish habitat. Tire dust is just one pollutant that’s toxic to many species of fish, most notably Coho salmon.

Unfortunately, many city engineers have been slow to take up rain gardens in their designs.  Each rain garden has a very unique set of circumstances and micro-habitats to consider.  Engineers prefer predictable and conforming drainage structures in their planning, even though such structures have a negative impact on environmental health.

So what is a rain garden and how does it help?

A rain garden gets rainwater that falls directly into it, AND runoff that’s guided into it from a roof or pavement.  What if every paved area or roof drained into an area full of soil and plants?   Deborah explained how there are many different methods to accomplish this.  Roof downspouts can be re-directed into existing or new plantings.  Curb cuts in medians can allow street runoff to flow into median plantings (as on Lougheed Highway near Ikea).  Curb free streets can allow street runoff to enter boulevard plantings.  Even green roofs are a type of rain garden!

You can see some good examples on the website.

Rain gardens filter out pollutants that would otherwise travel unchecked into our natural waterways. Rain gardens beautify neighbourhoods, make mini forests, and help suburban trees reach their full potential by providing them with abundant water supply. They can stretch along an entire ditch or boulevard, or they might just be “pocket gardens”.   Deborah showed us many examples of wonderful “before” and “after” projects in all shapes and sizes.

Cougar Canyon elementary was their first school project in 2006.  We thoroughly enjoyed viewing the amazing transformation of the boulevard.  Seeing all the children enthusiastically involved was so inspiring!


Deborah’s delightful little dog, Lawrence, was a “lead supervisor” (!), and was featured in his own book detailing the process.  It was published by the Cougar Creek Streamkeepers, Delta BC in association with The Nature Trust of BC, North Vancouver BC. Several other organizations were involved, including “Stream of Dreams”.

Make your own rain garden!

Your roof can provide a lot of water!  It is an important resource for replenishing groundwater.  Deborah showed how extenders can be used for roof downspouts, to guide roof runoff where you want it to go in your garden.  Sometimes you can even remove an entire section of roof gutter and let rain “sheet flow” from the roof into perimeter plantings. Deborah cautioned us to consider safety first, however, before disconnecting your downspouts!

A diagonal “speed bump” can divert water from a sloping driveway into adjacent plantings.  Ditches can be attractive when planted. Rain barrels are another great idea.  There are so many options!

Deborah brought some very useful resources including:

Checklist for Successful Rain Gardens

9 Common Problems in Rain Garden Design/ Installation/ Maintenance

Visit North Delta’s Rain Gardens (map of 26 rain gardens!)

If you visit the Cougar Creek Streamkeepers website, you will also find that the Delta Rain Gardeners program has an excellent “Maintenance Manual”.

Thank you, Deborah, for a thoroughly engaging presentation!   We learned so much about rain gardens! I’m sure we will become aware of how our community is (or is not!) stepping up to protect our precious water.  Since your talk, I’ve now noticed “curb gaps” that align with the slope of some roads in Coquitlam.  The abundance of cattails in those ditch rain gardens proves they are working!  We know you will keep working hard to “spread the word”.   The next step is for US to see how WE can redirect our own downspouts to make our own rain gardens!


Toronto Region Conservation Authority

How to Build a Rain Garden

Rain Gardens: A How To Manual for Home Owners

Rain Garden Design

University of BC – Why are rain gardens not more common in BC?

City of Vancouver

Para Space: Do Rain Gardens Actually Work? Why They’re Changing Vancouver