Harrowsmith Fall 2019 | 203HOME & DESIGN: GREEN DRIVEWAYI was being a little ridiculous,
and dropped it. Spring was
always over too soon, and if the
mud puddles got a little too deep
and wide, Dad would spread the
gravel again.
Years later, when I bought a
home near downtown Montreal,
I got a driveway of my own. It was
asphalt, and every year, some
workman would pass by and
quote me a price for repairing the
little cracks that the plants grew
through. The plants didn’t bother
me, but other people suggesting
it was unseemly did. Rather than
get out the Roundup, I hatched a
plan that was the polar opposite.
One reason cities are
several degrees hotter than the
surrounding countryside is
because pavement and buildings
absorb, reflect and radiate heat
from the sun. Another is because
water isn’t retained by the soil
and by plants for transpiration,
which cools; instead, it’s wicked
away and sent by sewer to the
nearest river. There are fewer
plants and trees to offer shade
and the productive absorption
of sun and heat, and that means
biodiversity only thrives in spots
where it’s left alone.
For the people who do have
gardens and lawns, they use
municipal water to keep it lush.
Anyone who goes through a
drought period knows what
happens then—and down south,
the xeriscaping movement
corrects the misuse of water by
planting arid-tolerant plants.
One study of watershed
modelling in the southwestern
U.S. suggested that permeable
driveways and retention basins,
also known as swales, reduce
peak flows of rain runoff by 14
and 30 percent respectively.
Rainwater captured from roofs
has the potential to provide for
up to 70 percent of the domestic
annual per capita water use, at
least in the region of the study.
Here, it could offset demand too.
This also means reduced
flash floods at the local level.
Retaining the water means you
can have a greener yard or water
the garden less. The increased
moisture and greenery means
you have a cooler environment.
A home’s driveway is like a
welcome mat for the residents,
their guests and passersby.
Considering all this, I decided
to make it a welcome mat for
everything. My little single-car
driveway could help address
these problems—and because I
love watching and welcoming
wildlife, I could especially focus
on the biodiversity part—simply
by returning my driveway to its
roots. Literally.
Here’s how we did it.
We excavated the asphalt
and sent it to recycling. Then, to
capture the rainwater from the
eavestroughs, we dug a trench
from the downspout, across