Communities with storm water ponds on thin ice

Many of Edmonton's new construction communities have storm water ponds, a wonderful water feature that is trendy for a variety of good reasons. Recreational skating and pond hockey are not some of those reasons.

Environmentally sound and economical for developers and municipalities to build and maintain, storm water ponds are different from natural ponds or even dugouts out on the farm. There are at least 160 storm water ponds in the City of Edmonton, many in new communities where they've become a neighbourhood lifestyle selling feature. Many are right outside people's back doors and in winter, the temptation to scrape off the snow and set up a rink for shinny is pretty big.

Research in Edmonton

Edmonton scientists have spent some time the last two winters using equipment such as a radar machine and tools to measure ice thickness to measure the effects and ultimately, the safety of skating on a frozen storm water pond. Now they're examining the data.

At this point, their study has revealed what the City of Edmonton already knows and has warned citizens about. They are just not safe, not matter how cold the winter is and no matter how long the ice has been forming for. Those aren't the only factors in ensuring ice thickness. The thickness of the ice on lakes and storm water ponds in the suburbs of Edmonton is not as reliable as natural ice on not-made-by-man bodies of water found out in the country. Storm water ponds are always shifting because runoff from the streets and drainage water can flow through these small ponds all through the winter. A pond could be frozen solid on the weekend but in a few days' time, the quality and thickness of the ice could be dramatically altered.

The highly unpredictable nature of storm water pond ice is caused by warmer and turbulent water coming into the pond and creating channels through the water which can weaken ice even if it's frozen all the way to the bottom. Runoff that comes into a storm water pond comes off Edmonton city streets which have been sprinkled with road salt after snowfall. This will also speed up thawing and affect the integrity of the ice.

Because of the unpredictable nature of water flow and all the contaminants that can flow into them, including anti-freeze from road runoff, signs warning the public about skating on ponds have always been posted. They are frequently ignored but scientists conducting the study suggest that people educate themselves about the hazards.

Storm water ponds may be deeper than what people imagine. In addition to the obvious problem of falling through the ice and the resulting hypothermia and potential drowning, storm water is dirty and full of the aforementioned contaminants, adding to the unpleasantness of falling in.

The City is in the practice of issuing warning letters to residents of new Edmonton communities where people are seen skating on storm water ponds. As Edmonton continues to grow and storm water ponds continue to be part of runoff management in these communities, skating on what potentially may be thin ice will be more of a concern.