They’re becoming an ever more common sight at our parks, schools and other community spaces, these little dry creek beds lined with ferns, flowers, bushes and trees.
But these rain gardens, as they’re called, are more than simple decorative elements to spice up a boring piece of lawn; they’re helping to make our streams and creeks healthy year-round.
Simply put, a rain garden is any landscaping that receives and soaks up rainwater runoff from an impervious surface such as a parking lot, street or roof. Deborah Jones of the Cougar Creek Streamkeepers organizes and constructs rain gardens in the area, including builds done in partnership with the Corporation of Delta and the Delta School District.
“The idea of a rain garden is instead of wasting rain water from a roof or a parking lot or a street down a pipe, out to a creek and out to the ocean within a couple of hours, instead we’re going to use nature’s free reservoir, which is the ground, to store that water,” Jones said.
In most cityscapes, this water is funnelled into drains and piped away. This leads to chronically low levels of groundwater in the hot, dry summer months and, in turn, to low water levels in local streams and creeks, causing water temperatures to become dangerously high and threaten fish survival.
“Right now there are parts of Cougar Creek that look completely dry because we haven’t stored enough rain water in the ground to feed the creeks,” Jones said. “A lot of people think that the only part of the area that’s important is what’s next to the creek, but that’s not true. Wherever you are standing, anywhere on Earth, you’re draining to a creek, or an ocean or a lake or whatever.”
Deborah Jones (right) of the Cougar Creek Streamkeepers helps the kids at Trinity Lutheran Church’s day camp build a rain garden on nest to the century-old sanctuary on Aug. 26. Photo credit: Linda Bartman
On the other side of that coin, whenever it rains a flood of stormwater runoff enters local waterways via catch basins and culverts, carrying with it pollutants that can harm fish health, and sediments that can suffocate spawning gravels where salmon have laid their eggs. As well, the high volume of water rushing by can wash away fish eggs, erode streambanks and destabilize the stream-side shade trees that are critical for salmon survival.
To help keep groundwater levels high enough to sustain our creeks year-round and to help filter the water entering our waterways, more people and businesses are building rain gardens. Recently, the children at Trinity Lutheran Church’s day camp helped Jones build a rain garden next to the century-old sanctuary.
“Deborah connected with us to envision what was possible with this rain garden, and then we decided to incorporate it into our kids camp for the week, with our theme being ‘growing green kids,’” said Rev. Jennifer Wilson. “We have all these kids from the neighbourhood – there’s about 30 kids that have come, ages five to 12 – who have all helped make the rain garden happen thanks to Deborah’s kind of worker bee or ant colony approach to making a rain garden happen. She’s got quite a system in place.”
Wilson said the experience of building the rain garden has been a positive one for the kids. With about two acres of forest on church grounds and Norum Creek running basically under the building, she says it’s been a good opportunity to teach them about the natural world hiding in plain sight.
“It’s been a great education tool for the kids. It’s very practical, they’re actually engaged in digging in the earth and moving it around so that it takes care of the animals and the creatures that inhabit the waters
and the land around us,” Wilson said. “It’s been a very exciting week for all of us. Hopefully the kids go home and have a better sense of how they can be better caretakers of Creation.”
The new rain garden at Trinity Lutheran Church will receive roughly 64,000 litres of water per year from about 64 square metres of the church roof. Photo credit: Linda Bartman
Jones said the garden will receive roughly 64,000 litres of water per year from about 64 square metres of the church roof, and it’s just one of 25 rain gardens constructed in North Delta thus far. Construction recently wrapped up on a second rain garden at the North Delta Recreation Centre, and Jones will be leading a one-hour workshop on rain gardens at the site on Saturday, Oct. 1 at 10:00 a.m., following which participants will help to plant it. (Register online at deltareg.ca/Start/Start.asp or by calling 604-952-3000.)
Later in the month, Jones will be helping students at Gray Elementary plant their new garden, located in a boulevard strip in front of the school. Plans are also afoot to construct one in the 80th Avenue right-of-way behind McCloskey Elementary, pending the final okay from BC Hydro. If it goes ahead this fall, then McCloskey students would likely plant in late October or early November.
Although the increasing interest in rain gardens is a step in the right direction, Jones acknowledged that we have a long way to go before our urban streams and creeks function the way nature intended.
“The work we’ve done so far, even though it’s 25 rain gardens and we’re infiltrating probably somewhere around 15-million litres of water a year, that’s literally a drop in the bucket,” Jones said. “We’re getting more and more impervious surfaces, more roof area, bigger houses, more dense housing. So these projects, what they’re really accomplishing is educating people about how we can design our cityscape better in the future.”
For more information on North Delta’s rain gardens, visit the Cougar Creek Streamkeepers website at vcn.bc.ca/cougarcr.
(Below: Map of all the rain gardens that the Cougar Creek Streamkeepers have helped build in North Delta.)