Camrose Storm Sewer System

The Yellow Fish Road in Camrose

The Camrose Storm Sewer System removes excess rainwater from the City to aid in flood prevention. There are 17 separate drainage basins that discharge independently into Camrose Creek through the storm sewers. The system includes 48 km of pipeline (2004) varying in size, from 300 mm (12 inches) to 2100 mm (84 inches). The majority of the water must be transported by gravity into the Creek meaning that all the pipes must slope downhill. The City does have a pumping station that pumps water out of the wet pond at Superstore and West Park. These ponds are working together as a single pond connected in series in which the water would be pumped out after the water event.

Since the primary purpose of storm water collection systems is to remove excess rainfall, they traditionally have not included treatment of the water, and therefore discharge directly into streams or other water bodies. Modern design standards require storm water retention in order to reduce the discharge rate. This mitigates erosion problems and allows some of the sand and silt to settle out of the water before it is discharged.

The City has developed strict bylaws in the City of Camrose Sewer By-Law to control the harmful substances that may enter the system.

The City of Camrose, in conjunction with many local organizations and schools, has implemented a community awareness program called the Yellow Fish Road. This program educates the public about the hazards associated with dangerous substances being carried by rainwater from yards, lanes, and streets into the Storm Sewer System and Camrose Creek.

Urban development, if not properly designed, can have a serious impact on runoff rates, which can affect local ecosystems. Before being developed, Camrose was a highly agricultural area, consisting of fields and a few small, forested areas. 95% of the rainwater on this type of landscape is absorbed by the soil, and the other 5% runs off slowly.

As development occurs, the amount of moisture penetration is reduced because the landscape is covered with pavement, sidewalks, and buildings. Instead of being absorbed, rainwater then runs off and, unless controlled, runs off more quickly. This increased runoff volume/rate, increases the potential for flooding and erosion in the developed area and downstream.

Higher runoff can damage the streams and rivers by increasing erosion and the amount of sand and silt in the stream. To limit this erosion, storm water retention ponds have been developed, which slows the runoff rate. Ideally, the rate of discharge from a storm water retention pond should match the runoff rate that was present before the area was developed. By maintaining the runoff rate, the possibility of accelerated erosion is reduced. This means that although larger quantities of water are running off and returning to the Creek, the adverse effects of this increase on erosion are reduced. The most severe and immediate threat caused by increased runoff is flooding. This can cause costly property damage and can be devastating to people in the affected area. The steps the City of Camrose has taken to reduce the risk of flooding are discussed later.

Runoff can also raise the level of harmful substances washed into the creek. As rainwater flows overland and into storm sewers, it absorbs many substances from roads, lawns and fields. These substances are then transported with the rainwater into the creek. The amount of pollution entering our Storm Sewer System would be significantly reduced if people remember:

1. Not to over-fertilize their lawns
2. To limit the amount of pesticides and herbicides they use
3. Not to dump wastes directly into the storm sewers, or onto roads, lanes, or fields where they will be washed into the sewers.

These three simple steps can help protect our environment from harmful substances.  (Click here to learn of more steps that you can take.)  In addition to these steps, you can get involved in Camrose's Yellow Fish Road program.  To learn more about the Yellow Fish Road program, or to become involved in this program, please contact the City of Camrose Engineering.

Alberta Environment and other government agencies are struggling with how to regulate pollution from storm water runoff. Due to the high volume of water and because the existing systems usually discharge at many different points, the cost to consolidate the lines and treat the water would be enormous.

All new storm systems must now include a 24-hour retention system. The retention time helps slow runoff rates, reduce erosion, and permit silt, sand and other debris to settle out of the water. This retention is usually achieved by installing a storm water retention pond. Although these retention ponds are very effective at reducing erosion, they are not effective at removing water-soluble substances, such as lawn fertilizers or pesticides.

Due to our relatively small size, runoff from the City of Camrose has not had a major impact on Camrose Creek. In fact, Mirror Lake acts as a large storm water retention pond and significantly reduces runoff rates protecting the creek downstream. The City is working to make sure that, as Camrose continues to grow, the issue of higher runoff rates and treatment is addressed responsibly.

The Camrose Storm Sewer System was designed specifically for rainwater diversion, not for disposing of other types of waste. This means that no treatment system is in place. The City has developed a strict bylaw to prevent hazardous materials from being dumped into the Storm Sewer System or in any location where it can be washed into the system. The City has also worked to educate the community about the hazards of dumping into the system through programs such as the Yellow Fish Road.

In the Sewer Bylaw there is a list of compounds, which cannot enter the Creek. In some systems this water is diverted to a storm water retention pond before entering the Creek. This helps prevent erosion and reduces the runoff rate and can reduce the size of pipe required downstream of the pond.

The minor system is designed to accommodate small storms. In new developments the minor system is designed to accommodate all of the rainfall from a 1-in-5 year storm (the worst storm which would occur, on average, once every five years) without street flooding.

The major system is designed to divert water that exceeds the capacity of the minor drainage system, by directing the flow overland to the Creek. This system is constructed by grading roadways, parks, and even residential lots so that water flows away from buildings toward Camrose Creek. Modern systems are designed to accommodate a 1-in-100 year storm without significant flooding on private property. The major system is not usually obvious to a casual observer as the system only operates once every 5 to 10 years during very major storm events.

On-site systems control runoff from a development on private property before it gets to the municipal system.

The systems include roof water retention, site grading, landscaping, parking lot retention, and flow restrictors. Even a single family home can be designed to significantly reduce runoff. Roof leaders can be directed to rain barrels where the rainwater can be stored for future use. The site can be graded so that rainwater is absorbed into the lawn rather than running onto a concrete surface, which cannot absorb water very readily.

Recently constructed storm sewers in Camrose have incorporated storm water retention ponds to the Storm Sewer System. These ponds help limit the environmental impact that large quantities of runoff can have on the landscape. Storm water ponds collect rainwater quickly through large intake pipes that come from areas around the pond. The water is retained in the pond and some of the solids are able to settle out of the water.

The other end of the pond has a much smaller pipe that restricts the water flow out of the pond. The small output of the pond limits the environmental damage of a large storm by slowing the runoff rate, down to a rate that closely resembles the pre-development rate.

Flooding is a major concern in urban areas because of the severity of property damages.

In 1995, the City of Camrose participated in a joint Federal, Provincial and Municipal study to define the 100-year flood plain in Camrose. A 100- year flood is defined as the worst flood, which would occur, on average, once every 100 years. The study determined that the worst flooding would likely occur as a result of spring runoff, not a summer storm.

To ensure property is safe from a large 1-in-100 year flood, the City has limited land use in areas that fall within the 100-year flood plain.

The flood plain is composed of a floodway and a flood fringe. A floodway is the section of the flood plain that contains fast moving, deep water. Development is prohibited in the floodway of a 100-year flood. The flood fringe is outside of the area of the floodway, but is still within the flood plain. The water in this area reaches a maximum depth of less than one metre deep and the flow rate is slow. A child weighing 20 kg is able to stand in the flood fringe area without being swept away by the current. Building is permitted on the flood fringe, although it is not recommended. Buildings constructed in this zone must meet flood-proofing requirements and may not be eligible for provincial or federal flood relief in the event of flood damage.

The flood plain in Camrose is relatively small due to the well-defined valley that surrounds the Creek. Even in severe 100-year floods, very little property will actually be affected (although several roads and walking paths will be closed).

The Alberta government has created a website which allows users to investigate flood risks for specific municipalities in Alberta, including Camrose, based off of the floodway & flood fringe areas in the 100 year flood. Click here to access this free informational website.

Most homes constructed after 1950 and other buildings with subsurface levels were constructed with foundation drains. Foundation drains collects and removes ground water around the foundation of the building.

If positive surface drainage is maintained away from the building, very little surface water enters the foundation drain, so the flow is limited to a small amount of ground water. Unfortunately, over time, grading around many homes and buildings settles and surface water infiltrates in foundation drains becoming significant during and immediately after rainfall events.

The foundation drains from homes constructed prior to 1994 were generally connected to the sanitary sewer. Unfortunately, rainfall infiltration to foundation drains was creating so much flow that it was overloading the sanitary sewer mains and using up significant capacity of the sanitary treatment system. In 1994 City Council followed the lead of other Alberta Municipalities, and passed a by-Law prohibiting connection of any new foundation drains to the sanitary sewer system (except with special permission from the Engineering Department - given in exceptional circumstances, and only if lot grading meets standards). Foundation drains were then required to discharge to the surface.

In the new areas of Camrose developed after 2001 a third service connection is installed to carry ground water and foundation drainage away from the home to the storm sewer. This is normally a 75mm pipe (3"). A sump is installed in the basement of the residence and a sump pump lifts the water to the foundation draining system. An air gap is provided so that if the storm sewer system in the road way is overloaded during a major storm, water cannot travel backwards into the residence's basement.

You can protect your own property from flooding by taking a few simple steps to reduce your risk. First ensure that all your eaves, downspouts, and downspout extensions are clean and attached properly. They should direct the water to a point at least 3 m away from your foundation. This will help conduct water away from your home and reduce the risk of basement flooding. Another important step in reducing your risk of flooding is to ensure that your property is properly graded so that water in your yard flows away from the foundation of your home towards the street or lane.(Basement Flooding and Sewer Backup Info)

A well-landscaped yard can significantly reduce the chance of flooding. The ground should slope down and away from the house to keep the foundation dry.

Flowerbeds and rock gardens next to a building can be problematic, especially if roof leaders discharge into them, or if lot grading does not direct water away from the house.

If surface water is allowed to flow to the building foundation the weeping tiles can be overloaded. This can lead to foundation damage and basement flooding.

In homes without weeping tiles, water at the foundation will eventually lead to foundation problems and water in the basement.

In areas where foundation weeping tiles are tied directly to the Sanitary Sewer System they can easily overload the Sanitary Sewer System and can cause sewage backup. Sewage backup usually happens at the location with the lowest basement, not necessarily at the properties where the landscaping is causing the problem.

By ensuring that your lot is properly graded and that your eaves and downspout extensions are functioning properly, you can significantly reduce the likelihood of flooding.

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