Westview Drive Rain Garden (2010)
Westview
Drive at Cougar Creek, 1 block south of 72nd Avenue, North Delta
Road to nowhere
On North Delta’s Westview Drive, about a block south
of 72nd Avenue, a stretch of pavement heads west only to end abruptly at
the banks of Cougar Creek. This is what remains of an old service road
that used to cross the creek and the Burlington Northern & Santa Fe (BNSF)
railroad tracks, providing maintenance-vehicle access to trails, the
GVRD’s (now Metro Vancouver’s) sanitary sewer lines and the site of the
old Westview Peat Plant.
When no longer needed, the road was literally
“chopped off” at the creek’s edge, the culvert removed, and the
creek opened up to a more natural condition – a great improvement
for fish habitat, but not very attractive.
The site has become an informal parking area,
for walkers who access popular creekside trails and the Delta Nature
Reserve from this trailhead.
Large-scale engineering and environmental
improvements may eventually have to be undertaken in this area, but
meanwhile, it cried out for an immediate facelift and some
stormwater mitigation, however modest. See
Northeast Interceptor.
A creekside rain garden
No matter where a rain garden may be located, it
always serves to remove pollutants and replenish groundwater that
eventually will make its way, underground, to a creek.
Westview Drive Rain Garden is Delta’s first
immediately-creekside project, whose benefits to Cougar Creek are
clearly visible in “real time” during every rainfall.
Large volumes of rainwater runoff from the
nearby stretch of Westview Drive used to pour into a standard storm
drain, which then fed directly via storm sewer into the creek. Other
runoff flowed (and still does) between and under concrete traffic
barriers and into the creek.
The old storm drain still receives some runoff,
but most is now diverted into one or another of 2 rain garden
intakes. Right away, large amounts of sediments are trapped at the
intake zones, that otherwise would have gone straight into the
creek. (In just 3 winter months, Streamkeepers removed 6 gallons of
sediments from the intake zones.)
The runoff then flows down through a series of
small pools, each of which provides more sediment/pollutant removal,
and an opportunity for the water to soak into the ground.
Small rain events are completely absorbed.
Medium to large events produce excess water that overflows into
Cougar Creek. For now, a silt fence further filters the overflow.
Once the garden is fully established, plants will do the job –
especially the Juncus effusus (common rush) that is
generously planted in or beside the infiltration pools. True to its
“effusus” name, the rushes will multiply “effusively” in their new
home.
Many hands make light work
As with Delta’s growing roster of school rain
gardens, Westview Drive Rain Garden is a product of cooperation:
-
Delta Engineering designed the garden and
interpretive signage
-
Engineering Operations did the
earthwork and installed bollard-&-chain fencing and new,
graffiti-free traffic barriers
-
Pacific Salmon Foundation provided a
grant for purchasing plants and signage
-
Streamkeepers coordinated and
supervised the planting, mulched with woodchips afterwards, and
are monitoring the garden’s performance in its first rainy
season
-
Last but certainly not least, Seaquam
Secondary School’s “Operation Green” did the planting – 300
plants in about 1½ hours.
Countless walkers, many with their canine pals, now
pass between the upper and lower portions of Westview Drive Rain Garden,
on their way toward the Delta Nature Reserve. Many have complimented the
great improvement in aesthetics, and are pleased to learn that it’s an
environmental improvement as well.
Visit Westview Drive Rain Garden in the rain!
Watch how it functions, read the interpretive signage, and imagine
how you too might retain and infiltrate rainwater on your own
property, to help reduce pollution and erosion of local creeks such
as Cougar.
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Cougar Creek