The Regional District has, since at least 1981, regulated development within the floodplain associated with Osoyoos Lake through its zoning bylaw and designated the “floodplain” as being any area with an elevation lower than 280.70 Geodetic Survey of Canada (GSC) datum.

These regulations have further required that the floor system or pad which supports a habitable area (e.g. the underside of the wooden floor system), is not lower than the flood construction level, which is generally the 200-year flood level shown on available provincial mapping.

The provincial mapping that the Regional District has relied on to apply these regulations was prepared in the late 1980s.

In 2020, the Okanagan Basin Water Board (OBWB) completed the Okanagan Mainstem Floodplain Mapping project, which involved the development of updated floodplain mapping.  

In early 2026, the Town of Osoyoos adopted amendments to its Official Community Plan (OCP) and zoning bylaws to increase the floodplain elevation of Osoyoos Lake within the Town’s municipal boundaries from 280.70 metres GSC datum to 280.80 metres GSC datum based on the recommendations contained within a Flood Mitigation Plan (2022) completed by TRUE Consulting Ltd (which incorporated data from the 2020 OBWB floodplain mapping project).

As Osoyoos Lake is situated within both the Town of Osoyoos and Electoral Area “A” in the RDOS, it is being proposed to update the floodplain elevation of Osoyoos Lake from 280.70 metres GSC datum to 280.80 metres GSC datum to ensure consistency between the two jurisdictions.

Zoning Amendment Bylaw No. 2800.64, 2026 proposes amendments to Section 10.0 (Floodplain Regulations) of the Okanagan Valley Zoning Bylaw No. 2800, 2022 in order to update existing floodplain regulations associated with Osoyoos Lake and to replace the existing provincial floodplain mapping with a new, updated floodplain map.