It's late May, and you're walking through the community, and something doesn't look right.
You can see a pool of stagnant water where a pool shouldn't be.
Or you might be filling a pothole on a community road, and notice a culvert end that is completely caved in,
crushed by a backhoe or a truck.
These are two signs that something isn't right about the drainage situation in your community,
and that something needs to be done to fix the problem.
All drainage systems deteriorate over time. It's a fact of life.
But with a changing climate, it's happening faster in the North because of things like:
An increase in extreme weather events which could mean more snow
Winter rain, icing and higher winds
Rapid spring melting, and more.
This video is designed to explain a new National Standard of Canada for community drainage
system planning, design, and maintenance, developed SPECIFICALLY to meet the needs in
a changing North and developed by the CSA Group and approved as a National Standard
of Canada by the Standards Council of Canada.
The National Standard of Canada for Community Drainage Systems sets out the minimum planning,
design, and maintenance requirements for community drainage systems in the North.
Drainage systems aren't obvious to the eye, and in many communities, a lot of the system is buried.
That's why a map that shows where culverts are, what size they are,
and the direction of the flow is an essential thing to have on hand.
A copy of that map can easily go in any vehicle in the fleet, and it's one of the handiest tools you can have.
Let's break the maintenance cycle down by season.
In the spring, inspect all the culverts to see if backed-up melt water is present.
Clear out debris from the ends of the culvert in spring too. Do it by hand, with a backhoe,
or an excavator. Clear any blocked culverts, so water can flow freely.
You can use an oil-fired steamer or a hot pressure washer to melt frozen blockage from
the downstream end of the culvert.
Always start at the end of the drainage system, and work your way upstream.
Remember that some culverts may re-freeze at night when the temperature goes down,
and may need to be opened again.
Keep a close eye on meltwater pouring onto a roadway or a driveway approach.
The water can erode it pretty quickly if it isn't diverted.
After a major rain and during spring runoff, take a close look at the outlets of the drainage system
that are closest to the discharge location.Those outlets should be inspected for litter and other debris from the community
that sometimes gets carried by the drainage water.
The National Standard of Canada recommends
that the entire drainage system be inspected during runoff and rain events so you can identify deficiencies,
and make note of them for repairs over the spring and summer while the system is active.
After the spring runoff, at the beginning of summer,
it's time to inspect the drainage system again and identify problems.
Develop a plan and get to work. Activities can include:
Re-sloping ditch bottoms or lowering downstream culverts to eliminate ponding that has begun to happen in ditches.
Mowing or cutting back any vegetation that has become overgrown around culverts
and other drainage ditches
Flushing blocked culverts to remove sediment, rocks, and other debris. You can use a water pump
attached to a water tanker to do this job
Cutting back, replacing, or bending open collapsed culvert ends
Replacing or reinstalling any culverts that have shifted or moved
In the fall, water levels in the North are usually at their lowest.
The National Standard of Canada recommends that maintenance and repair
of saturated areas of the drainage system be done in the fall.
Now is a good time to inspect culvert marking posts, and replace any that have become damaged.
Remember how important these are in winter, when culvert ends can't be seen because of snow cover.
(6.6.5.1) In winter, snow removal from building roofs
and community roads becomes a major priority,
Well before snow begins to fly,
go all around the community and carefully mark these key pieces of your drainage system:
Outfalls Drainage ditches
Culvert ends Culvert marking posts.
Here are key points from the National Standard of Canada about managing snow removal.
The key things to keep in mind:
It's difficult to tell when a flash thaw could take place.
Melted snow is dangerous because when it overloads
the drainage system, it can damage road surfaces, and if there's a flash freeze before those
roads are repaired, the freeze-up can cause even more damage.
Snowmelt from snow that's been removed should be prevented from re-entering the drainage system.
Piled snow that melts and goes back into the drainage system as runoff can overload
the system and cause damage or flooding. Find a place to store removed snow that is well
away from the drainage system.
Identify the most important culverts and make sure they get thawed first. Remember, always start farthest
downstream and work your way up.
If possible, build snow berms or use snow fences outside of the community to trap windblown snow,
so it stays out and doesn't put more pressure on the system during spring runoff.
If you build berms, they need to be touched up and maintained throughout the winter.
For instance, when the snow trap becomes full it won't be effective, so berms will need
to be pushed up.
Now here are some additional measures you can implement to keep your community drainage system in top shape.
Let's start with erosion and sediment control.
The flow of water has force, and over time, it can do enormous damage.
That's why we need to:
Make sure there are plants growing in ditches. Their root structure helps prevent erosion.
Mow ditches to make sure larger plants don't take hold. Their roots are not helpful
and can create larger problems as they grow
If your community runoff contains silt, it's important to keep it out of water courses
that contain fish habitat. Use a silt curtain
Finally, in places where discharge water runs strong and at high volume, place riprap
or large rocks at your culvert exits. Riprap and stones are heavy, and less likely to be
moved by water flow. This helps to prevent washouts.
Maintenance is the key to success in Northern drainage systems,
and monitoring is the best way to stay ahead of the game.
No matter what time of year, here are things to always watch for:
Flooding Standing water
Poor or slow drainage Damming
Ground subsidence (where the ground is suddenly lower than it should be)
Erosion
Overgrown culvert ends
Blockages or excessive debris like leaves , litter, grass, rocks and silt
Excessive vegetation that slows down or blocks water flow
6.9.3 Here are the places to check carefully when
you inspect your drainage system for proper operation:
Hillsides Streams
Gullies Road crowns
Ditches
Swales Culverts
Channels Dykes
and Infiltration areas.
Repairing damaged culverts is a normal part of drainage system maintenance.
Here are some tips taken from the new standard of Canada:
When cutting culverts, coat pipe ends with a zinc-rich primer
When opening up culverts, a hydraulic jack can help to restore flow and save a more substantial repair
When shoring up a culvert after a washout, or when water is flowing through a washed out section,
use drain rock or pea-sized gravel to eliminate the amount of finer material
that might wash out and be lost. Then use riprap rock to armour the affected area
so a washout won't happen again.
To find out more about this and other standards developed as part of the Northern Infrastructure Standardization Initiative,
vist the Standards Council of Canada's website at www.scc.ca where you can access all of the NISI standards free of charge.
Thanks for watching