Updates to Flood Plain Mapping

The Province requires that the City have policies in the Official Plan (OP) and provisions in the Zoning By-law to prohibit development within the one in one hundred year flood plain. As such, a program of updates to improve the accuracy of the flood plain mapping and to add newly mapped flood plain areas were included in the department’s 2015-2018 Planning Committee-approved workplan. Updates will be carried out through Official Plan and Zoning By-law amendments, which will occur over a number of years, as mapping becomes available from the conservation authorities. The first phase of these amendments is anticipated to be brought to the Agriculture and Rural Affairs Committee and the Planning Committee in April 2016.

The City of Ottawa has partnered with all three local conservation authorities to update the flood plain mapping contained in the Official Plan and Zoning By-law. Mapping is being updated by the conservation authorities through City funding. The new mapping reflects the most up-to-date elevations of land adjacent to watercourses. The first phase of updates will apply to the lands shown on the key in the map below.


Technical amendments to the policies contained in section 4.8.1 of the OP are proposed to distinguish between areas within the flood fringe portion of the flood plain (where depths and velocities are generally less severe), and areas of reduced risk (lands within the flood plain that are protected by flood control works, but are not in the flood fringe).

In addition, a new policy will be proposed so that the OP, Schedule K, no longer requires amending each time flood plain mapping within the Zoning By-law is amended. Schedule K shows the general location of the flood plain but, given its scale, most of the amendments would not be distinguishable.

The intent of the proposed amendments is to reduce the risk of flood impacts. The amendments will apply flood plain provisions to some lands, and remove flood plain provisions from other lands. While the development potential of some lands may be negatively impacted as a result of the amendments, the development potential of other lands will be positively affected.

If a landowner wishes to develop within an area where new flood plain provisions will be applied, staff will advise of the risks of building in the flood plain. If the property owner is determined to develop on lands that will be subject to flood plain provisions, despite being advised of the risk, they have a right to apply for and obtain a Building Permit until such time as the amendments are approved by City Council and come into effect.

Notices will be sent to affected community associations and technical agencies in early December. Ads will be placed in the EMC and Le Droit on December 3rd. A detailed map showing the current boundaries and proposed boundaries of the flood plain overlay in the Zoning By-law is available by going to ottawa.ca/floodplain. An Official Plan and Zoning By-law amendment report is anticipated to go to Planning Committee, Agriculture and Rural Affairs Committee and City Council in April 2016.