Reducing The Flow Of Spring Run-Off

       By: Nicholas L. Bott, CAC, CIT

Too Much of a Good Thing

Water - it is the most important resource we have. Everything is connected to it and we will perish within days without it, but too much of it at once can be a bad thing. And nowhere is that more of a problem than during our Canadian spring run-off.

Urban run-off is the excess water that runs off of impervious surfaces like roofs, parking lots, roads, patios - even turf on compacted, perfectly graded suburban lawns. The water cannot filter back into the ground through asphalt and concrete, so we end up draining away our most precious resource. Canadian songstress Joni Mitchell says it best when she sings, "They paved paradise and put up a parking lot".

We've created a setting that inhibits infiltration and promotes the movement of water away from the home and into a storm sewer. Once it's there it's joined by all of the other impervious surfaces in your area which, in urbanized areas, can be hundreds to thousands of square kilometers! A heavily urbanized area like Toronto (7,125 sq.km) will generate over 185 billion gallons in a single rain event! That's huge! That's enough water to create a column of water the size of a football field extending up 35 kilometers into the atmosphere! That's equivalent to 64 CN Towers stacked end-on-end!

Even though Canada is home to 25% of all the fresh water on earth, only 0.3% of it is stored in lakes and rivers. All remaining sources are held in groundwater aquifers. As development occurs, impermeable urban landscapes are not allowing these natural aquifers to recharge. Despite dramatic changes in agricultural irrigation practices and water conservation initiatives, groundwater levels have declined in North America by as much as 11% since the 1950s.

Crumbling Infrastructure

And our municipal storm water infrastructure is failing us too. In the City of Ottawa, during a rain storm in 2006, an aging water control on Keefer Street jammed open for two weeks spilling 1.2 billion liters of raw sewage into the Ottawa River. This environment catastrophe resulted in a $450,000 fine from the Ontario Ministry of Environment. The spill was blamed for unprecedented bacterial contamination of the public beaches on Petrie Island - now nicknamed Putrid Island.

The City of Ottawa has over 2,690km of water mains and drainage sewers supplying over 755,000 customers. However, that water infrastructure is aging fast with much of it over 40 years old and literally rotting away. Dr. Yehuda Kleiner, who leads the buried utilities research group at the NRC Institute for Research in Construction estimates that costs to replace aging water utilities in North America could exceed $1 trillion over the next 20 years. Without significant increases in property taxes or water rates, who will pay to replace it?

Sustainable Storm Water Solutions

Civil engineers have been trying in vain since the 1960s to solve storm water problems by building settling ponds, pumping stations, and increasing sewage line capacities. All this has done is increased infrastructure costs, and deferred the financial liability to future generations. The real solution is to begin decentralizing storm water management. Why should the rain water draining off the roof of your house travel through 250km of municipal sewers, and dump into the Ottawa River when green solutions for urban run-off are right under our nose! Here are a few simple, sustainable storm water solutions you can implement into your own home landscape this spring:

Decorative Rain Barrels

The Greeks and Romans first developed rain water harvesting over 3,000 years ago. They used to divert rain water off of rooftops into basins carved into bedrock so that it could be used later on during periods of drought. Modern rain barrels do essentially the same thing except that existing models create such an eyesore beneath downspouts; as a consequence few people have installed them - until now. The Pond Clinic has responded to your cry for aesthetically pleasing sustainable solutions by introducing the RainXchange Decorative Rain Barrel.

Product Features

•  Extra large 75-gallon capacity!

•  5-year warranty

•  Requires no electricity

•  Large safety overflow keeps water in the barrel or away from the house

•  Lid can also be used as a planter

•  Thick plastic walls are durable and will withstand extreme conditions

•  Childproof lockable lid

•  Brass spigot for garden hose connection

Product Benefits

•  It's SIMPLE . The RainXchangeT Rain Barrel can be incorporated into existing gutter and drainage systems.

•  It's RESPONSIBLE . If every single family home in Ottawa installed a RainXchange Rain Barrel, every time it rained, over 12 million litres of polluted storm water would be prevented from flowing through our over burdened sewer system and into our rivers.

•  It's BENEFICIAL . Harvested rain water is better for plants than municipally treated water.

Rain Gardens

Rain Gardens and Bio-Swales are popular methods and they're being promoted across Canada as an effective storm water micro-strategy. Mother Nature has been doing this since the beginning of time. You basically just need to slow the water down and give it a chance to soak into the ground.

Rain Gardens and Bio-Swales are very simple to create:

•  Redirect your downspouts away from the storm sewer system, and allow the water to flow

over land to specially designed areas or depressions either natural or manmade.

•  These depressions should be excavated to break up the compacted upper soil layers.

Mix sand and organic matter with the soil to keep it loose allowing for water infiltration.

•  The area is then planted with a mixture of ornamental wetland plants that can handle both wet and dry conditions. The plants will aid in filtration by removing organic pollutants as they pass by the root zone, and some of the water will also be transpired by the plants back in to the atmosphere. Garden centers specializing in aquatic plants can assist you in choosing the appropriate varieties.

•  The plants will provide the added benefit of habitat and food for a large variety of animal

and insect species by creating damp wetland areas which are in decline in the natural environment. Creating rain gardens helps protect the fragile biodiversity in your area.

AquaBlox French Drains

Although most people believe assume that the French drain originated in France, the concept was actually created and popularized by a Massachusetts lawyer named Henry French (1813-1885) in his book Farm Drainage . Original forms of French drains were simple ditches, pitched from a high area to a lower one and filled with ¾" clear drainage stone. Water would flow between the gaps between the drainage stone and eventually percolate back into the ground, recharging the surrounding water table. French's own drains, made of sections of ordinary roofing tile, were laid with a 1/8" gap left in between the sections to admit water. In 1967, Armtec Corporation introduced a flexible, perforated polyethylene drain pipe called Big 'O' and it has been the industry standard ever since.

Traditional French drains do have one significant shortfall, however. Storm water from surrounding landscapes and rooftops tends to bring along with it debris, soil and sand which can clog up the ¾" clear drainage stone layer and plastic inflow pipes. They also tend to have very low water holding capacity.

In 2008, Aquascape Inc. introduced two new products and an innovative, cost-effective way to manage residential storm water run-off:

•  RainXchange Downspout Filter - Installed in the ground and out of sight at the base of the eavestrough downspout ready to capture & remove a variety of debris & pollutants that may be flushed into the French drain during a rain events and spring run-off. Incoming water is passed through a series of mechanical filters that remove leaves, twigs, seeds, and small sediment that accumulate on the surface of roof tops and impermeable surfaces between rain events. Clear storm water can then flow freely from the RainXchange Downspout Filter without the risk of clogging the layer of clear drainage stone in the French drain.

•  AquaBlox Water Matrix -. Aquablox are plastic, cage-like modular tanks that create a catchment system designed to replace the ¾" clear drainage stone used in traditional French drains. They are both lightweight and strong enough to be installed beneath permeable paver patios & driveways. Aquablox French Drains also hold 3.5 times more water than traditional French drain systems. They also require less excavation, less labour, and allow storm water to percolate back into the ground at a much faster rate.

We're HereTo Help You

So you've decided that you want to do your part to reduce urban run-off and you're ready for action, but you don't know where to start. No worries! Our helpful retail store staff at The Pond Clinic can help you design a Rain Garden or an Aquablox French Drain System; and they can also supply you with all the products and coaching needed to install it right. Come visit us before the end of March and beat the spring rush.