Chronic flooding in a west-end Ottawa neighbourhood may be traced back to the design of a nearby stormwater pond, a city engineer suggests.

Ted Cooper said a 2003 study shows the water in the pond rises to an elevation of over 95.6 metres. That means it could flow more than a metre downhill before gathering in the basements built in the nearby Kanata neighbourhood of Glen Cairn, which was most recently flooded during a storm in July.

"You know, when you look at the history of development of Glen Cairn, and the construction of that stormwater pond, one would think that something has fallen through the cracks," Cooper told CBC News.

Cooper, who has a previous track record as a city whistleblower, sent a letter over the weekend to city councillors representing west-end wards and to the Glen Cairn Community Association, alerting them to the problem, providing details and suggesting some possible solutions:

• Reconfiguring the Glen Cairn stormwater management pond.
• Lowering the profile of the nearby Carp River.

He added that he was sending the letter as a concerned citizen, rather than as a city engineer.

After receiving the letter, at least one city councillor has asked staff to review the findings and report back.

Cooper said the basements in the neighbourhood were built at or above 94.5 metres, based on a 1973 grading plan that set that as the level of the flood plain. The stormwater pond was dug by the Mississippi Valley Conservation Authority in 1978.

Request for audit

Glen Cairn has been flooded three times in the past 13 years. The most recent incident this past July prompted a frustrated resident to alter this 'For Sale' sign. (Julia Kilpatrick/CBC)Attached to Cooper's letter to city councillors was a letter addressed to Ontario Premier Dalton McGuinty, asking the Ministry of Natural Resources to conduct an immediate audit of the conservation authority, which is responsible for managing the watershed in the Glen Cairn area.

"Based on research that I have undertaken, there is clear evidence that MVC is responsible for the authorization of channelization and development work in the Glen Cairn and Bridlewood communities that has resulted in an increase in flood levels in the Carp River basin by nearly four feet in the worst impacted area of the Glen Cairn community that has now been flooded three times in the last 13 years," the letter said.

Allan Hubley, vice-president of the Glen Cairn Community Association, said Cooper's findings, if true, are worrying.

"We expect the city to step up and take responsibility for the sewage now and build another pumping station," he said, "and do the work that's need to make sure not only that we don't get any more sewage backup but that we don't get any more stormwater problems, either."

Cooper had previously blown the whistle on flaws in the plan for Ottawa's massive Kanata West development. That error in flood predictions prompted the city to put the development on hold in February 2008. The city's auditor general later confirmed the errors.

Ted Cooper attached this diagram of Glen Cairn to his letter to city councillors, explaining his theory on the cause of the flooding. (Courtesy of Ted Cooper)