Something fishy with Carp River pathway plan, say observers

(Above: A heron and ducks swim along the Carp River between Hazeldean and Maple Grove.  This photo looks north towards Maple Grove from the Hazeldean Road Bridge.)

After years of delay, restoration of the Carp River in Kanata and Stittsville will start this fall, but some observers say the planned recreational paths will be prone to excessive flooding.

Erwin Dreessen of Ottawa’s Greenspace Alliance is one of several people in the community who’ve been keeping a close eye on development around the river.

“The design would see those pathways flooded with a two-year storm,” he says.  “It’s not in accordance with what one expect with responsible government to approve… I find this very disturbing.”

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A contract to carry out the work — a project known as the Carp River Restoration Plan (CRRP) — will be awarded on September 11 and construction is expected to start shortly after that.  It covers 5.2km of river from Hazeldean Road to north of Richardson Side Road.

The City of Ottawa, along with the Kanata West Owners Group (KWOG) has been developing the plan since 2000.  It’s the blueprint for an engineering project that would alter the existing Carp River to reduce flooding during spring runoff and heavy rainfalls and allow for more nearby development in what for years was considered a floodplain.

KWOG, the consortium of landowners who control most of the property along the river, are paying 70% of the cost of the restoration. In 2006, City Council agreed to pick up 30% of the tab, in part because of the benefit that the recreational pathways would provide to residents.

The first phase of the work (from the 417 to Richardson Side Road) is expected to be complete in fall 2016 and future phases (from the Queensway south to Hazeldean) will be done by the end of 2017.

In 2006 the total price tag was estimated at $5-million.  The most recent estimate, based on a preliminary design, is $14.8-million, according to the City.  The final price tag won’t be known until the tender process is complete.

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THE START OF THE WORK THIS FALL WILL FOLLOW YEARS OF STUDIES, CONSULTATION AND CONTROVERSY. The final design that was tendered by KWOG earlier this summer went through the scrutiny of a variety of governments departments and agencies from the municipal to the federal level.

“We’ve actually been through many years of very rigorous approvals. The approvals that we have, we have them from the City, from Mississippi Valley Conservation Authority, from the federal Department of Fisheries and Oceans, the Ontario Ministry of Environment, the Ministry of Natural Resources, and even the Ministry of Transportation just to go under the freeway bridge… This has taken many many years to get the point we’re at now.” said Kathleen Willis, the project manager for KWOG.

What Dreesen and others are concerned about are the flood elevation levels. Early plans called for recreational pathways at a 1:100 year flood elevation. As the Mississippi Valley Conservation Authority explains: “A 1:100 year flood is a major flood that risks causing serious damage to people and property. These major floods have a 1% chance of occurring in any given year. To compare, a 50 year flood has a 2% chance of occurring in any given year. Simply because a major flood occurs does not mean that it cannot re-occur the next year.”

Just a few centimetres change to the elevation, up or down, can have a large effect on the possibility of flooding.

Now, some sections of the remaining pathway are planned at a 1:2 to 1:10 elevation, meaning that there’s a 10-50% chance of flooding in any year.  That could mean the Carp River would overflow its banks and cover the pathways with anywhere from 30-100 centimeters of fast-moving water.  (One report suggested that signs warning of the possibility of flooding could be put up along the path to mitigate the safety risk.)

Besides the safety factor, there’s also the clean-up.  Every time the Carp floods the pathway — a 1-in-2 chance of happening each year — there will likely be clean-up required to get rid of the mud and debris that the river leaves behind.

There have been other tweaks since the last time the public was consulted on the plan during an environmental assessment in 2010, including skinnier pathways (from 4 meters down to 3), changes to fish habitat ponds, and the elimination of two pedestrian bridges over the mighty Carp.

“The current design approach is to build the pathways at grade to the river between the 1:2 and 1:10 year elevations. The final elevation of the pathway system will be in accordance with Provincial standards and City requirements,” the City said in an email attributed to Don Herweyer, Manager of Development Review.

“Each project is unique in the context of the Carp River and other situations across the City – recreational pathways are set at different elevations. In the case of the Carp River the proposed elevation of the pathway is the most appropriate design solution,” he wrote.

Just last year, the City spent about $400,000 in nearby Glen Cairn to elevate the pathways in Ravine Park to 1:25 year flood levels. That ravine feeds into the Carp River close to Terry Fox Road.

The Hazeldean Road bridge over the river was completed in 2011 with pathways underneath built to at least a 1:10 year flood level.  

Besides concerned citizens, at least one Ministry of Environment engineer has asked questions about the plan.

“Will the proposed pathway meet the City’s risk management policy with respect to parks and recreational facilities? Will the pedestrian pathway conform to the City’s risk management policy for stormwater conveyance infrastructure?” wrote Charles Goulet in a March 2014 email obtained via a freedom of information request.  “…The mix of flooding waters and children is a dangerous one.”

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WE CONTACTED THREE COUNCILLORS with wards that include parts of the Carp River, and asked them if they had concerns about flooding on the pathways.

“I do not have significant concerns with the pathway elevations,” wrote Stittsville councillor Shad Qadri. “Yes, there will be times when there is significant rainfall that the pathway ‎may flood, however that is often the case with parks and pathways in other areas of the city. In those cases residents exercise caution or avoid the area until it has dried.”

“I discussed the elevation of the pathways with staff last year and found out that they could not be higher as they need to have clearance under the Campeau Road bridge that will cross the Carp and it would be both difficult and expensive to raise the bridge higher due to soft soils in the area,” wrote Kanata North councillor Marianne Wilkinson.  “Temporary flooding of pathways is common – for example the paths along the Beaver Pond in Kanata North sometimes flood but they soon drain off and paths along the Ottawa River in West Ottawa do the same during the spring runoff.”

“Ravine (Park) is more than recreational as it links over 2,000 people to their only bus stop on Eagleson,” wrote Kanata South councillor Allan Hubley. “We also had significant erosion of private property issues that had to be dealt with thanks to a bad design in 2003. Unless there is special circumstances such as just provided, there is no reason for taxpayers to pay for the higher design level. The new pathway from Cope to Eagleson for example would be at same lower level.”

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THE PATHWAY PLANS ARE JUST THE TIP OF THE ICEBERG when it comes to issues with the CRRP, according to Dreesen.  He’s concerned with many aspects that he’s seen over the years, often uncovered through freedom of information requests.

“There’s so many things that have been done the wrong way throughout this whole saga,” says Dreesen. “We see flooding problems, we see a river that’s been badly abused, and we see it all seemingly motivated by a desire on the part of the development community to gain more land.”

“Eventually nature will give its answer. Let’s hope there’s no loss of life,” he says.