Rain, Rain, Rain

A few days ago, Victoria had over an inch of rain in one day. This was a reminder that we are on the coast, and winter is the rainy season here. The word "rainforest" was coined for a reason!

Forest, Mt Douglas

Goldstream Park. Photographer: Cory Schadt Source: https://commons.wikimedia.org/wiki/File:Goldstream_Provincial_Park,_Victoria,_Canada

Natural areas, like the rainforests of Mt Douglas or Goldstream Park, absorb a good part of the rain when it falls. The ground has a thick layer of absorbent organic material, laid down over decades, that acts like a gigantic sponge.

And then there are our urban areas, with large swaths of "hardened" surfaces. When rain falls on hard surfaces, it usually is collected and diverted to storm sewers.

Parking lots present hard surfaces which are notorious for collecting rainfall and sending it to storm sewers, rather than allowing it to infiltrate into nearby ground

Managing rainwater is a challenge for cities which receive a lot of rainfall. 

I've been exploring how Victoria's residents handle rain. Traditionally we have piped rain water "away", through storm sewers which ultimately empty into the ocean.

Definitely there are times when storm sewers are needed. But piping water away can reduce water availability in the dry season of summer - and Victoria receives little rain in that season.  

Also, in times of heavy rainfall, storm sewers can be easily overloaded.

Cities are developing a different approach to managing rain water and storm water, exploring ways to keep it in place, rather than pipe it away.

Piping stormwater "away" down storm drains is the traditional engineering approach. And definitely, it has its place. But storm sewers can be vulnerable to flooding - as the sign points out.

Rain water flow in Beacon Hill Park is overwhelming the drainage system. Grass does not absorb water the way a spongy rainforest does.

Too much water for the grass in the park

Another image of squelchy grass

So, grass is not so good at absorbing rainfall, as the above images show. 

I have been encountering various yards covered with a variety of more absorbent surfaces. A few examples follow. I start with alternatives to hard surfaced parking pads and driveways.

Pavers like these are popular. They allow more rainwater to infiltrate than a completely paved surface.

This infill house has chosen pavers instead of asphalt or concrete for its driveway.

Parkside Hotel. Pavers extend into the underground parking. Also, notice the landscaping shrubbery and areas of moisture absorbing trees. 

Another James Bay house with pavers for its parking area. This house also has a putting green, which neighbours are invited to use.

At least one of my neighbours regularly wanders over to this welcoming house on Niagara Street to practice his putting.

A different view of the house, showing the putting green in the background. This is the home of a dog lover, whose previous dog has left a legacy for other dogs in the area.

And now - back to storm water!

Layers of deep soil with organic material are good at absorbing rainfall. 

The perennial bed for this apartment absorbs much more rainfall than a similarly sized area of grass.

An attractive perennial bed for a single house with a walkway made of flag stone.

Deep perennial beds help absorb rainfall in this yard. 

This elegant perennial bed has a trench of drain rock in it, to help with drainage.

This house also has a drain rock channel, seated within a perennial bed.

Pavers used for sidewalks in a housing development

These pavers are used for the house's driveway. The muddy strip in the centre illustrates how difficult it is for bare ground to absorb rainfall.

Another option: paved tracks for the wheels, coupled with ground filled with organic material to absorb rainfall .

Here is another example of paved track for a vehicle's wheels, with the rest of the yard landscaped with water-absorbing vegetation and ground cover.

A gravel sidewalk and a perennial bed help this yard with rainfall absorption

Another attractive yard landscaped with pavers and deep perennial beds

Storm water carries pollutants from vehicles and other runoff and can contaminate surface water. Here is one method I have observed, near Fisherman's Wharf, for protecting surface water. 

The City of Victoria's storm water system includes four storm water "rehabilitation" units. These are large tanks used to capture sand, silt and oils before they are discharged into the ocean. There is one at Fisherman's Wharf. The outlet has a secondary cover, shown above, which can be opened for cleaning.

Cities have long been aware of the need to protect storm water from pollutants; witness this storm sewer cover that has been around for a long time.

Imprinted into the grate are the words "Dump No Pollutants"

What is more recent is the understanding about the importance of reducing storm water flows. 

The City has a 4 minute video which shows its goals with storm water management. See https://www.youtube.com/watch?v=ZInD7sZZ7Y4&feature=emb_logo

The bottom line: the more we allow the ground to absorb storm water in place, the more we imitate nature's water cycle .