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Flooding FAQ

Visit flood preparation to learn more about how The City is preparing for potential flooding in 2014, as well as what you can do to prepare yourself.

Flood recovery programs

What is The City doing about erosion on private property?

The City is responsible for public safety and public infrastructure and assets. When it comes to private property, the owner is responsible for recovery of their property.

We are working with the Province to prepare information to help guide the design and approval process for owners wanting to repair erosion damage. We are sharing flood records, river models, data, and guidelines for analysis, design and construction practices.

We will also meet with owners in a pre-screening meeting to address questions and identify available information to support their decisions. It is the private landowner's responsibility to contact the Province and the Federal government regarding their site and recovery plans, and ensure compliance with provincial or federal regulations.

If you want to recover your property:

  • Request a pre-application meeting through our Flood Recovery page so we can provide information and guidance on repairs.
  • Where possible, work with your neighbours to develop a common design across adjacent properties and do the work together. This will make the building process more efficient and offer greater protection against further erosion, while protecting local habitat.
  • Use the existing processes and package your information together. Submitting one application for you and your neighbours is recommended.
  • Ensure you follow regulatory requirements and the instructions for the pre-application

What programs exist to help me recover from the flood?

Property owners, business owners and residents can find more details about flood recovery assistance programs or support information on our Calgary Flood Recovery page.

Impact of 2013 flooding

Calgary had a significant amount of snowfall this winter. Does this mean the city will flood again in spring 2014?

There are many factors that impact whether Calgary gets flooding from year-to-year. Although we experienced higher than normal snowfall this winter, snowmelt within the city will not cause flooding. The amount of snow in the mountains is currently within a normal range. Snowmelt in the mountains must be combined with intense rainfall to result in river flooding during flood season (May 15 to July 15).

As this flood season approaches, The City's river monitoring team reviews forecasted weather patterns, river flows and mountain snowpack to determine the potential for flooding. Coordination occurs between the river monitoring team, the Provincial flood forecasting team, city emergency response groups, and City business units involved in operating City facilities, such as the Glenmore Reservoir.

Learn more about our monitoring efforts on the flood preparation page.

Will events like the 2013 flood occur more often?

Every year there is a one per cent chance of a similar flood occurring. We will have floods in the future, although the frequency and size of these events is difficult to predict.

How will river changes affect future erosion and flooding?

The 2013 flood added significant sediment, soil and rocks to the Bow and Elbow Rivers. We are studying these areas to understand what changes occurred and the potential impacts.

Based on initial assessments and observations during the 2013 flood, The City does not anticipate increased risks of flooding or changes in the areas that experienced flooding due to changes to the river.

Will river changes impact ice formation?

We are currently studying ice formation on the Bow River. An ice monitoring program is in place to assess the possibility of river ice build-up and any impacts this may have on the river or infrastructure. The contributing factors for ice formation such as bridges have not changed; however, some problem areas may have shifted.

What kinds of issues do ice jams create?

Ice jams primarily cause groundwater seepage into basements. Although The City ensures its storm system is draining properly, private land owners need to ensure they have emergency response measures in place to prepare for groundwater seepage, such as sufficiently sized pumps.

Predicting floods

Can floods be predicted?

Historically, floods occur between May 15 and July 15, although there are a few incidents before and after this period.

The City's river monitoring team and provincial forecasting team monitor forecasted weather patterns, river flows and mountain snowpack year-round.

If stream flows rise and it begins to rain, Alberta Environment puts out notices that fall into these categories: high stream flow advisory, flood watch or flood warning.

While conditions might seem right for flooding, weather in Calgary and the surrounding foothills is unpredictable and can change rapidly. So, while we may assume that flooding will happen, it's sometimes difficult to accurately predict.

To learn more about our monitoring efforts, visit the Calgary flood preparation page.

What does history tell us about flooding?

The City and Alberta Environment study flood plains and historical occurrences of flooding. This information is compiled into flood risk maps. These maps can be used to estimate areas at risk for flooding to a certain level.

Flood maps often show various levels of predicted and worst-case scenario flooding; however, estimating flooding beyond the "100-year flood" is a difficult task because there is a lack of historical flood information to compare.

Phrases like "1-in-20-year flood" or "1-in-100-year flood" are an estimate of how often a flood will occur in a given time period based on the amount of the flooding.

The longer the time period, the larger the flood event. What it means is that a 1-in-100-year flood will, statistically, have a one per cent chance of occurring in any given year. It would be rarer and much bigger than a 1-in-20-year flood.

This does not mean that if a 100-year flood happened this spring, it wouldn't happen again for another 100 years. It could happen again in the following year or even twice or more in any given year.

Preventing floods

Why don't dams stop flooding?

There are 11 dams along the Bow River before Calgary. The closest is the Bearspaw Dam on Calgary's western city limit, and the Glenmore Dam on the Elbow.

These dams are not designed for flood protection, but rather electric power generation. They also store water for various water systems on the river. That said, dams provide a small amount of protection by slowing the release of water temporarily.

What efforts does The City make to prevent flooding?

The City constructs berms, dykes and floodwalls in high-risk areas along the Bow and Elbow rivers.

For the 2013 flooding, we have identified 185 flood-related infrastructure projects requiring repairs or restoration work. See a full list of the projects and their location on the flood recovery page.

We are repairing critical riverbank sites in Calgary to address public safety. Learn more about our riverbank stabilization efforts.

An Expert Management Flood Panel of nationally and internationally recognized experts has also been created to examine, evaluate and prioritize environmental, infrastructure and policy measures that would significantly reduce potential harm from floods.

Why can't you provide sandbags to residents?

The City identifies key locations (which may include some residences) where sandbags are needed to protect critical infrastructure or facilities needed for emergency operations. Locations that could cause significant damage to communities, drinking water, storm sewer systems or other utilities are given maximum protection with limited resources.

Unfortunately, it is not possible for The City to provide sandbags to hundreds of thousands of homes. It remains the responsibility of the property owner to protect their property, and sandbag, as required.

Does The City upgrade areas that are at risk?

The City evaluates potential storm sewer improvement projects in communities subject to flooding before every construction season.

Evaluations are based on these safety considerations: amount of flood damage, number of floods in each area, and cost-effectiveness of the project. These projects are funded by the drainage charge on your utility statement.