Erosion Control vs. Sediment Control
The overarching principle of Erosion Control vs. Sediment Control is that it is much easier and cheaper to prevent erosion from occurring in the first place than to try and remove the sediment once it has eroded.
Erosion and Sediment Control is a rapidly changing field. Traditional approaches have been applied with varying levels of success over the years. In addition, there are a host of new approaches, practices, and proprietary products that should be shared, understood, and considered on construction and municipal sites. Sites can be sustainably managed by minimizing the impact of earthwork using proven erosion and sediment control measures..
Erosion Controls are source controls designed to prevent erosion from occurring. Solutions include seeding solutions like hydroseeding and terraseeding, wood chip mulch and rolled erosion control products.
Sediment Controls are downstream controls designed to remove sediment from runoff. Solutions include sediment fences and barriers, filter socks and other forms of mechanical filtration.
At the detailed design stage impacts can be minimized through efficient earthworks and erosion and sediment control measures. It is vital that development be successfully completed in balance with the natural environment.
The Erosion and Sediment Control Association of British Columbia is a non-profit organization is dedicated to increase the level of expertise in the Erosion & Sediment Control field throughout British Columbia. Their list of Best Management Practices are divided into Erosion Control and Sediment Control solutions that we think you will find useful.
Protecting Fraser Valley Dykes from Erosion
Protecting Fraser Valley Dykes from Erosion of the Fraser River Banks
Starting in the Rocky Mountains, and pouring into the Strait of Georgia, the Fraser River is B.C.’s longest river, and largest flowing into the Pacific seaboard of Canada. The Fraser is a busy river: it is home to sturgeon, a provider of water for pulp mills, and in the Fraser Valley, its banks neighbour rich farmland.
After settlers came to the Fraser Valley, they were met with the power of the Fraser River. 1894 brought a disastrous flood to the region when the area had no defense against the rising waters of the river. A dyking system was soon created, but in 1948, with lack of care for the aging dykes, and the banks protecting them, another even more consequential flood, devastated the region, with an equivalent of over $200 million in damages.
In 2013, new erosion on the banks of the Fraser River raised an alarm. Existing erosion arcs, where strong currents had worn down the soft silt at the bottom of the riverbank, were monitored, and advancing development of a new arc called for immediate action, as it was only 30 meters from the dyke; the spring freshet could mean a repeat of history for the area. The dyke was protecting over 12,000 acres of diverse agricultural land, the historic Clayburn and Matsqui villages, land belonging to the Matsqui First Nations, and major regional infrastructure, such as gas mains, water transmission main, and the wastewater treatment plant. Flooding of this area would have even greater negative impact than it did over 60 years ago, an estimated $2 billion in damages.
The city of Abbotsford called for help, and made an emergency repair in early 2014 on the bank using rock armoring, or riprap, providing a new boundary for the river’s flow. Use of riprap is beneficial, as it deflects the impact of the current, absorbing the energy of the water, and therefore protecting the bank. It also slows the flow of water, and provides further protection from debris that the river might be carrying.
An example of such work can be found in Denbow’s Strachan Point project, where Charles Creek erosion was a threat to a CN Rail bridge, the highway bridge, and two private bridges providing access to local homes. Building up and widening the creek bed, and then reinforcing with the process of rock armoring, eliminated the threat.
Long-term, the Fraser Valley has more work to do to fight erosion. Since the 2014 fix, two new erosion arcs have developed. The city of Abbotsford engaged the services of Northwest Hydraulics Consultants to undertake a study on the Fraser River erosion. Their findings urged the city to not only continue the upgrades to existing bank protection with rock armoring, but also to utilize rock spurs.
Rock spurs are linear structures, placed at the bottom of the bank, to assist in changing the direction of the river’s flow. This would slow the process of erosion drastically, by moving the force of the water away from the bank toe, which is where erosion arcs begin.
The city approved the proposed project in December 2015, with an estimated $8 million price tag. In April 2016, British Columbia’s Ministry of Transportation and Infrastructure announced $4 million will be provided for the project from the 2016 budget. While the Fraser Valley continues to fight to protect its land and livelihood from the power of the Fraser River, the Ministry has further committed to collaborating efforts to ensure the communities with potential impact are kept safe; work on upgrading the dykes themselves will also be prioritized.
Protecting Fraser Valley dykes from erosion of the Fraser River banks, proactive measures need to be taken. Erosion control will ensure infrastructure remains sound, homes are protected, farms flourish, and our historical sites live on.
Rain Water Harvesting
Rain Water Harvesting
British Columbia rain: too much in the winter, too little in summer
The “leftcoast” gets a lot of rain in the winter, so much it causes problems like flooding, sewer overflows, stream erosion, and polluted runoff into our waterways. But during our summer we get very little rain (less than Tucson, Arizona!).
So it’s hard to store enough water from spring rains to last long for summer irrigation. You need large cisterns or multiple rain-barrel systems to store enough water to have an impact on water usage. Simple practices like amending soil with compost, mulching, and smart watering are the first steps to storing and conserving water. The next step is capturing all that beautiful rain water that falls on our wet coast.
How much rain water can I catch?
The lower mainland of BC averages about 1,200 mm of rain per year, but 2/3 of it falls from November to March. Most areas in the region average less than 87 mm total rainfall for July and August.
The roof of your home is your greatest tool to harvest rainwater. To determine the amount of rain your roof catches, multiply your home’s width by its length (in feet) to estimate its footprint. Then estimate the portion of this area that drains to the downspout you’ll be using to catch your rain.
To calculate the runoff in liters from a metal roof’s 9 meter 10 meter “footprint” (90 square meters) in a climate averaging 304 millimeters of rain a year:
90 square meter roof 304 millimeters of average annual rainfall = 27,360 liters of rain falling on the roof in an average year.
90 m2 304 mm = 27,360 liters/average year
Multiply the above figure by the roof surface’s runoff coefficient 0.95*: 27,360 liters 0.95 = 25,992 liters running off the roof in an average year.
Storing Rain Water
Storing your harvested rainwater can be your greatest challenge. However, most homeowners don’t have room to store the thousands of gallons of collected rainwater that they use in landscape irrigation through our dry summers. Plus the cost of installing storage containers with enough volume to give you water through the entire summer would be very cost prohibitive and it would take a very long time to see the cost savings pay off it off.
Capacity and cost are directly related: decide how much you want to spend on building rainwater storage. Couple with this the practice of using mulches to regulate the soils moisture content and evaporation and you’re on your way to saving money and water throughout our hot summers and help you save water.
Vancouver Area Average Monthly Rainfall
| Month | Jun | July | Aug | Sept | Oct | Nov | Dec | Jan | Mar | April | May | June |
| Rainfall (inches) | 11 | 20 | 67.8 | 41.8 | 112.8 | 170.8 | 230.2 | 167.2 | 130.4 | 161.6 | 24 | 51 |
source WeatherStats.ca
Before you launch into a big project like rain water harvesting you can start with a few simple ideas. Begin by building soil with compost and mulching, choosing low-water use plants, and implement Smart Watering practices. Couple these ideas with simple indoor water conservation practices before investing in big rainwater collection systems to help you get on the road to water conservation without having to encounter major water expenses.
Remember, it isn’t rainy season but it does rain. So why not set up your rain harvest system now, while it’s sunny, so you don’t have to do it in the cold wet of our fall. Hope you enjoyed the article if you liked please feel free to share it with your friends!
Mandated Green Roofs in Toronto. Is Vancouver Next?
Green roofs have many benefits. They not only insulate the buildings they shelter but also improve air quality and reduce runoff, easing sewer system loads and preventing associated overflow. They cool in summer, reduce heat loss in winter, and can support birds and other wildlife. Where green roofs top public buildings, they create public green space and parkland. Living roofs can even help cool an entire city in the summer by reducing what’s known as the “urban heat island effect,” where traditional roofing and paving materials increase the overall temperature of the air.
With Toronto’s new Green Roof Mandate, it is well on its way to becoming Canada’s Emerald City. Thanks to a City of Toronto bylaw that requires green roofs on new construction, green roofs will see a dramatic rise in Toronto’s skyline. Residences, commercial and institutional buildings over 2,000 square meters must have a roof that’s 20-60 percent “living.” Green/living roofs are partly or completely covered by vegetation, planted into a growing medium and sitting over a waterproof membrane. They often include structural support, irrigation and drainage systems, and can even incorporate greywater treatment ponds.
With the living roofs, much of the rain fall will now be “absorbed” into the plants and lessen the burden on waste water treatment and storm water volumes. For the city of Toronto, this means that there will be four to five more beach days. That’s good news for everyone. The question for us in City of Vancouver BC is, are we next?
Read the article here.
Why Sustainable Development Goals Matter
Why Sustainable Development Goals Matter
As our neighbourhoods grow, and our needs as communities increase, development and ingenuity bring solutions to people today. The key to ensuring our solutions are long-term is found in the way we do development.
Why sustainable goals matter is simply, Sustainable Development involves a relationship between nature and humans that demonstrates respect for both. Though we may not always notice it, the natural environment provides a great deal for us, and at times needs some corrective procedures to continue providing for us in the future.
We can see how our relationship to nature is give and take. The Eco-System naturally produces rainfall, provides crops to farm, and protects humans from the elements. At times, for a variety of reasons, this system breaks down and human intervention is needed. Sustainable Development is a balancing act where both parties work together for one common goal, and without it, things begin to fall apart.
Denbow seeks to use innovation to work within this balancing act. Our team specializes in construction, agriculture, landscaping, and municipal/infrastructure, all of which use sustainable development techniques. An example of this is found in Denbow’s newer work in the areas of erosion and sediment control, using forest residuals.
One of the many products Denbow offers is manufactured soil. A mixture of minerals, liquids, organic matter and countless organisms, without healthy soil, the elements would be stripped and the land eventually destroyed. Soil holds everything together, and the right soil for the right project makes all the difference.
At Denbow, we use high quality blended soils that are produced with stringent guidelines for different kinds of use. This mixture of engineered soils can be used for a few specific purposes:
- Vegetable Garden Soil is rich in organic matter. Using this soil in your garden will help you grow the best, healthiest vegetables each season. Growing your own vegetables can give your family the vitamins and minerals our bodies need.
- Specialty Soils are proprietary blended. These are used for such projects as green roofing, structural soil for street tree growth and stormwater management. The structure of these soils are custom made and vigorously tested. Sustainable development projects often require creative measures, and specialty soils provide the perfect opportunity to meet the needs of the specific projects.
- Manufactured Soils are premium blends that contain various levels of compost and sand, designed to benefit trees and shrubs, turf health, and to rejuvenate depleted existing soil. Using these soils can restore existing greenery, or provide an important start for new growth.
Within the variety of soil produced by Denbow, we see how sustainable development starts in our own backyard. Using naturally produced materials, we can benefit from their use as we return them to the earth in our different projects, neither harming human nor the environment.
Denbow Innovations are full of products and services for sustained developments located in the Lower Mainland of British Columbia.
Phone for more information (888) 933.6269
” Delivering Satisfaction for Industrial, Government, Commercial and Residential Use”
Sustainable Development: TELUS Garden Receives LEED Certification
Sustainable Development: TELUS Garden Receives LEED Certification
Following an extensive review, the Canada Green Building Council awarded TELUS Garden Leadership in Energy and Environmental Design (LEED) Platinum certification. This is the highest rating a building development can receive. This honour was presented at today’s launch of the Smart Prosperity initiative at TELUS Garden, attended by Prime Minister Justin Trudeau.
Some of the leading edge sustainable development features of the building complex included:
- 10,000 square feet of outdoor meeting space and garden terraces on six levels planted with a community food garden that will be tended by TELUS team members, indigenous trees and hundreds of plants species;
- A district energy system that will reduce demand from conventional energy sources by 80 per cent and reduce carbon dioxide emissions by more than one million kilograms a year.
- High-efficiency motion sensor lighting to significantly reduce energy consumption;
- Advanced building systems, which include a ventilation system providing fresh air to residents and workers, rather than the recycled air typical of towers
Ian Gillespie, President of Westbank, which partnered with TELUS in this development project stated, “The LEED Platinum certification embodies our commitment and dedication to create a world class development where the sustainable design not only mirrors the culture and values of TELUS team members but also the tenants and businesses who have now become a welcomed part of this environmentally conscious community.”
To learn more about about this ground-breaking development, read the original press release here.
