We support competent remediation and improvement of the river and its flood plain along the entire length of the river from its source in wet lands on NCC land at Eagleson and Hazeldean Roads and storm water management ponds near Terry Fox (between Abbott St. and Hazeldean Rd.) in Kanata to its exit into the Ottawa River at Fitzroy Provincial Park in West Carleton.
We have advocated that the planning and development of Kanata West ensure that the following issues are adequately addressed with respect to the Carp River:
1. Correct flow models are used to calibrate the extent of remediation required.
2. The models take into account the additional runoff into the river that will occur from new residential and commercial hard surfaces (roads, driveways, parking lots) where before there were marshes and soils absorbing rainfall and melting snow.
3. The models also take into account the effect on down stream flooding during both the spring melt and significant storm events. Ideally the remediation should improve the current situation down stream, but as a minimum it should not exacerbate it.
4. The remediation methods used should trap and filter polluting runoff (salt, grease and oils, fertilizers, pesticides) from entering the river and being transported down stream. In addition, they should act as a “sponge” to allow slow release of water into the river thus tempering its flow over high volume events and drought. For example, an ecosystem of storm water management ponds, habitat ponds, and wetlands is a healthy approach to restoration vs. dredging and straightening to create a drainage ditch prone to erosion and pollution transport.
For the Kanata West development the City proposed a Carp River Restoration Project. Concerns raised by the Carp River Coalition (of whom we are a member) eventually led to a Third Party Review by Greenland International Consulting, who completed their report in March 2009. This was revised in May 2010: “Carp River Restoration Plan – Widening Alternatives Final Report” also by Greenland International Consulting”* to incorporate storm data from the record 24 July 2009 rain fall. It recommended the following changes to the City’s plan:
- additional habitat ponds or alternatively wet meadows from the Paladium Drive area to Richardson Side Road; and
- additional widening of the river by 3.8m to accommodate flow volume.
While we are generally supportive of the restoration and of the new recommendations, we still have concerns about down stream impact. The current restoration plan stops at Richardson Side Road. The opening of the Terry Fox Extension, which heads north at the edge of the river’s flood plain, and plans for new development on the eastern side of the road are adding more hard scape runoff and pollutants. The FCR would welcome additional remediation measures such as ponds and wetlands applied to the flood plain north of Richardson Side Road.