Sewers

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Sewer Connections

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Flood Prevention

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Why does flooding occur?

Flooding can occur if the sewer connection to a building becomes blocked by tree roots,grease, objects, or other debris. Occasionally, mainline sewers can also become blocked from debris or tree roots. In addition, because Vancouver has a large number of combined sewers(refer "General Overview"), major rainfalls can cause runoff drainage to exceed the capacity of the street sewer system resulting in sewer backups through plumbing fixtures in homes.

How do I prevent flooding from occurring?

Here are some basic preventative measures:

• do not put grease or objects (such as diapers, plastic bags and panty hose) down your toilet or drains.

• if you have a older home with old vitrified clay pipe you may want to consider replacing you sewer system with newer PVC or ABS pipe.

• consider installing a pump if you are the lowest property along a street. This approved method of reducing flooding risks is designed to continually pump wastewater from a private property under any storm condition. For further details on the standards and installation requirements, please contact the Plumbing and Gas Inspection Branch at 604-873-7574 or 604-873-7558.

• if you have a pump make sure that your pump is working properly , contact a qualified plumber.

• ensure that your storm sumps backwater valve is functioning properly

• regular maintenance of your pumps by a qualified plumber.

• keep storm drains clear of leaves and debris. In the fall, sweep up leaves for bagging or composting to prevent excess debris from entering the sewer system.

• consider having your plumbing cleared of any debris, roots, etc.

What should I do if flooding occurs in my home?

If you have a back-up of water and/or sewage in your basement, please:

• Check the toilets, sinks and waste pipes and clear any blockages.

• It that doesn’t solve the problem, you can call the Sewer Operations at 604-326-4680 and City staff will be dispatched. This is a 24-hour service, seven days a week. Make sure someone is home to let the City staff in or you can contact a private plumber to assist you.

• Avoid using your plumbing until the problem has resolved to minimize any damage.

• Make notes of everything that happens, i.e. from where the water comes in, what time it comes in, and anything you do to help alleviate the flooding. This will help our staff or your plumber determine the cause of the flooding.

Requesting a City Maintenance Crew

Upon contacting Sewers Operations at 604-326-4680:

1. Dispatcher will inform you of any possible charges.

2. Dispatcher will inform you that a cleanout or other approved access to your plumbing system is required. If you do not have a cleanout then your toilet will have to be removed prior to City Crews arrival. City crews are not authorized to remove or replace your toilets.

Upon City Crews arrival:

1. City crews will first check the public sewer system to check for any obvious problems. If no problems are found then Crews will enter your home to assess the situation.

2. Crews will attempt to remedy the sewer backup by using a variety of means.

3. After the Crew has completed their work they will return a report to a Supervisor with their findings. City Maintenance Crews do not determine responsibility . They are only there to clear the blockage.

4. If blockage is determined to be a City responsibility by the Supervisor,  then no invoice will be sent to the Owner or Occupant.

5. If it has been determined the blockage is not a City responsibility, then the Owner or Occupant will be invoiced accordingly.

What is the City doing to reduce the risk of flooding from sewer backups?

The City has developed and is implementing a number of initiatives to reduce the risk of flooding.

With regard to service connection blockages, the City undertakes the following programs.

• Precautionary Rodding Program - If sewer connections become repeatedly restricted or blocked by root intrusion from private or City boulevard trees, the City has established a program to clean out sewer pipes on a preventative maintenance basis.

• Sewer Connection Relay Program - This program has been established to relay the most critical and problematic public sewer connections within street right-of-ways. This reduces the flooding problems resulting from these connections. Engineering Services is also currently trying new trenchless technology methods to replace sewer connections. If successful, the cost to replace problem connections will be reduced, allowing the City to replace more connections through our Capital Works Programs.

With regard to backups from the mainline sewer system, the following initiatives are being undertaken to reduce and eliminate flooding.

• Local Sewer System Changes - Often, some cost-effective changes or pipe section upgrading can be made to provide increased capacity to accommodate greater rainfall drainage from storms. This involves making structural changes or advancing the reconstruction of parts of the sewer system.

• Infrastructure Reconstruction Program - This program rebuilds the City’s aging sewer infrastructure. Upgrading of older sewers generally occurs at the end of their useful lives which is usually 80 to 100 years. The City’s reconstruction program provides for the replacement of about 1% of the system annually such that all sewers are rebuilt on a life-cycle basis. All sewers replaced are upgraded to today’s higher capacity standards. This program requires a budget of about $14 million annually. The replacement value of Vancouver’s entire sewer system is in excess of a billion dollars. Because of the high cost of reconstructing sewers, it would be impractical to upgrade all of the older parts of the system to current standards over the short term.

• Sewer Separation - Vancouver’s older sewers were built as "combined" systems. This means that only single pipes were constructed in the streets to carry both sanitary sewage and rainfall runoff mixed together. If the runoff from an intense storm exceeds the capacity of the main sewer, sewage can back up in sewer connections to private properties and flood homes though their plumbing fixtures (e.g. toilets, bathtubs and sinks). The sewer reconstruction program replaces old combined sewers with new twin pipes to keep the sanitary system separate from the storm system. With a completely twinned system in place, backups through sanitary fixtures due to high intensity storms can be eliminated.

• Regulation of Sewer Connections - When applications are made for new sewer connections, the connection depths, plumbing fixture levels, and in some areas, the need for flow discharge controls are reviewed. Appropriate restrictions are required to reduce the possibility of basement flooding.

• Inflow and Infiltration Program - In separate sewer areas, the City has a program to reduce the amount of extraneous stormwater entering sanitary sewers. This program is currently underway in the Still Creek area and has been successful in rerouting stormwater into the Creek, thereby reducing flooding risks in immediate downstream areas.

• Impermeability Controls - Council has recently approved new RS-5 and RS-6 zoning for City neighborhoods to provide more control over the design of new homes. Along with other design guidelines, the new zoning contains a bylaw section to limit the amount of impermeable materials, including building coverage, to 60 percent of the total site area. This provides aesthetic benefits as more "greenspace" is retained and reduces the potential amount of runoff to the sewer system. Although this new zoning may not be appropriate for all areas of the City, the impermeability controls could be extended to other neighborhood zones.

• Sump Exfiltration Pilot Program - A pilot program has been established to evaluate the effectiveness of decreasing storm runoff from properties through the use of exfiltrating sumps. These sumps have been designed to allow stormwater from building roof leaders and drains to flow naturally into the ground as much as possible before discharging to the City sewer system. If found to be successful, a recommendation will be made to make this requirement applicable to all new home construction. (for more information see Perforated Sumps)

• Rain Barrel Program - "Rain Barrels" are used to store rainwater for garden usage thus conserving domestic water and reducing rainfall runoff from properties.

• Roof Leader Disconnection Pilot Project - A soil analysis has found that some areas of the City have enough permeability to allow disposal of roof leader runoff by infiltration into the ground. A volunteer roof leader disconnection pilot project was undertaken last fall in one area to assess the effectiveness of this type of program. Although our initial participation rates in the pilot program were disappointing, this does remain a viable option for reducing runoff in some parts of the City. (for more information see Roof Leader Disconnection’s)

• Flood Assistance Program - The City has now implemented a short term program to assist homeowners who have experienced flooding as a result of the City’s system backing up into their homes. Each flooding case is evaluated to determine if on-site measures can be implemented to limit future flooding. These measures include pumping systems, site grading and backflow preventors.

If you have any questions concerning flooding, please call Sewer and Water Counter at 604-873-7357.

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