OKANAGAN CLIMATE

The UBC Okanagan Campus is located in the ecological setting of the Okanagan’s Very Dry Hot Ponderosa Pine Zone.

Climate adaptation planning at UBC’s Okanagan Campus is fundamental to address climate change impacts. Sustainability – Campus Planning & Development is currently integrating adaptation measures into key plans, such as the Integrated Rainwater Management Plan (IRMP, 2017). The IRMP assesses and proposes measures to responsibly manage rainwater that falls on campus, thereby mitigating the impacts of the built environment on rainwater management. Climate modelling was an integral component to rain water modelling flows and volumes and associated IRMP recommendations for future campus development sites.

Climate

Mean annual precipitation (Kelowna Airport) is 298 mm, of which 102 mm (34%) falls as snow. High intensity rain tends to fall in the spring and summer seasons after the snow is gone. Approximately 25% of the campus has a high environmental sensitivity, representing primarily woodland and wetland ecological communities. With a diverse landscape of pine woodland and open grassland, the campus contains ecosystems and has plants and wildlife identified as being species at risk. Among those documented on campus are the Great Basin Spadefoot Toad and the Western Painted Turtle, which have been observed in certain rainwater features making maintenance more challenging and costly. Understanding potential changes to the Okanagan climate resulting from climate change will also need to be considered in planning the IRMP for the campus.

Trends for the Okanagan Region are expected to include increased annual temperature, increased annual rainfall (likely in shorter and more intense rainfall events), and decreased snowfall and snow pack leading to an overall decline in groundwater recharge and base flows during the summer.

Topography

Positioned along the ridgeline, the campus has three distinct benches and slopes and several low-lying areas that have developed into rainwater retention areas and wetlands.

Soil permeability

Soil conditions and permeability vary largely throughout campus. In general there is a coarse granular aquifer that is exposed in the lower elevations in Innovation Precinct, which is then capped with a thick layer of mixed silts, clays and cobbles in the higher elevations. In the highest elevations along the ridge is some bedrock. Hydrology has been extensively modified through historic development within the campus core.

The Water Cycle

The Water Cycle image depicts the cycle of water movement of water on, in, and above the Earth. The water cycle on campus is impacted by many factors including rainfall intensity, permeability of surfaces and soils and the volume of water that can penetrate and infiltrate from the surface. Promoting infiltration in a dry climate is important to recharge groundwater supply.

Snow Pack

Source: Ministry of Forests, Lands and Natural Resources, River Forecast Centre, Snow Survey and Water Supply Bulletin – 1st of March 2019

Weather patterns through February were very cold through the entire province as a stable arctic airmass remained in place for most of the month. Many cities recorded the coldest or second coldest average temperature for February. Temperature anomalies  anomalies in the southern interior were -6 to -9˚C below normal. The provincial average for all March 1 snow measurements is 89% of normal. Snow basin indices for March 1, 2019 indicate that the snowpack is slightly below normal to normal (80-110%) for the Okanagan.

So far this season, snow accumulation has been dominated by persistent weather patterns. Most of this years’ snowpack built up rapidly over a five to six-week period from early-December to early-January. Weather through February shifted into the dominance of Arctic air across the province, with extremely cold temperatures and limited snow accumulation. This pattern has continued into the beginning of March. Snowpack throughout the province remained relatively level through February. Most basins dropped by 5 to 15% relative to normal compared to February 1 due to the dry and cold conditions.