What are retention ponds?

All retention ponds are designed to handle large fluctuations in water levels. During wet weather events like large rain storms or spring snow melt, or because of a large water main break, the water levels of a retention pond may increase dramatically. Temporarily storing excess runoff in retention ponds helps prevent our sewer system from being overloaded, and helps reduce the occurrence of basement and overland flooding.

There are three types of retention ponds in Winnipeg.


These ponds typically have grass embankments and may have a stone shoreline around the perimeter of the pond.

traditional Traditional retention pond with a stone shoreline.


traditional Traditional retention pond without a stone shoreline.


Naturalized retention ponds are designed to have vegetation, like cattails and native prairie grasses, growing on their shorelines and embankments.



Dry ponds typically have grass embankments and are normally not filled with water.

These ponds may fill up with water temporarily during significant rainfall events or snow melt.


Pond maintenance

The City of Winnipeg maintains and operates fountains and underground structures found in retention ponds, such as pumps, wells and gates. Maintenance of retention ponds includes:

  • Removing debris in surrounding areas
  • Controlling grasses and weeds that grow through the stone shoreline
  • Managing aquatic vegetation like algae and water weeds

Traditional ponds may be maintained with herbicides or by harvesting aquatic vegetation. These activities are not required for naturalized or dry ponds, because vegetation in these ponds is beneficial and is growing there by design.

The City does not maintain shorelines or landscaping on private property.

Water fountains

Some retention ponds are equipped with water fountains. These fountains are for aesthetic purposes, and were installed by the developer of the subdivision in which these ponds are located. They do not provide aeration for the purpose of controlling or eliminating algae or weeds.

Water levels

Retention ponds are designed to operate within a range of water levels. The water levels will sometimes fluctuate between their normal water level and what would be considered a high water level.

The water levels will typically rise as a result of a wet weather event, like heavy rain or snow melt. They can even rise as a result of a water main break. Water levels can rise significantly – up to 1.2 meters or more– and can last anywhere from a few hours to several days, before gradually returning to their normal water level. Weirs and pumps help to regulate a pond’s water levels, allowing for excess runoff to be temporarily stored and then gradually released into the land drainage sewer system.

Residents living adjacent to a retention pond should be aware that water levels can increase significantly on a short-term basis, causing temporary flooding around the pond. For this reason, residents should be mindful of this when deciding where to install structures, when landscaping or when storing items on their properties.

side view of retention pond

Properties adjacent to retention ponds typically have notable grade breaks or slopes leading down to the pond. These slopes, as illustrated above, can help residents determine where the retention pond water may rise to during normal and high-water level events.

Was this information helpful?

How can we make this web page better?

Information collected will be used to improve our website. Do not use this form to submit a request for service or information because it will not be forwarded to departments for response. To submit a request for service or information, contact 311.

This form is not intended to collect personal information; however, any personal information you choose to include in your comments is collected by the City of Winnipeg under the authority of section 36(1)(b) of the Freedom of Information and Protection of Privacy Act for the purpose of improving our website and will not be used or disclosed for any other purposes, except as authorized by law. Contact the Corporate Access and Privacy Officer by mail (City Clerk’s Department, Susan A. Thompson Building, 510 Main Street, Winnipeg MB, R3B 1B9) or by telephone (311) if you have any questions about the collection of this information.

Ces renseignements sont-ils utiles?

Comment pourrait-on améliorer cette page Web?

Les renseignements recueillis serviront à l’amélioration de notre site Web. Prière de ne pas se servir de ce formulaire pour soumettre une demande de service ou de renseignements, car la demande ne sera pas transmise au service en question. Pour soumettre une demande de service ou de renseignements, veuillez communiquer avec le 311.

Le présent formulaire ne vise pas à recueillir des renseignements personnels. Cependant, les renseignements personnels que vous choisissez d’inclure dans vos commentaires sont recueillis par la Ville de Winnipeg en conformité avec l’alinéa 36(1)b) de la Loi sur l’accès à l’information et la protection de la vie privée dans le but d’améliorer son site Web et ne seront ni utilisés ni divulgués pour d’autres raisons, sauf dans les cas où cela est autorisé par la loi. Communiquez avec l’agent de l’accès à l’information et de la protection de la vie privée de la Ville par courrier au Bureau du greffier, immeuble Susan-A.-Thompson, 510, rue Main, Winnipeg (Manitoba) R3B 1B9, ou par téléphone au 311 si vous avez des questions sur la collecte de ces renseignements.