Storm Water Retention Pond

June 2019 – Campus Pond Maintenance

January 2016
Campus Pond Maintenance Complete

Cleaner water, a healthy pond habitat, and a natural-looking amenity are among the benefits of UBC’s ongoing commitment to progressive storm water handling on the Okanagan campus.

Since1991, campus storm water has been directed to a small, artificial retention pond with a sealed liner bed on the east side of campus, behind the EME building.  Rather than putting the water into the City of Kelowna’s storm water system, the human-made pond was designed to look and function like a natural pond, and effectively treat storm water pollutants through evaporation and natural biological processes.

In 2011, a sedimentation forebay was added to the North side of the pond (Photo 1). The forebay acts as a natural sediment-settling area providing an initial depression where the first flush of storm water can collect and allow the suspended solids to settle out. The forebay also reduces the maintenance impact on the larger retention pond area and its wildlife inhabitants from periodic silt removal and servicing.

Since 2011, sediment input into the main pond has decreased significantly and the pond and forebay have functioned as designed and continued to provide the campus with a unique ecological feature for both learning and enjoyment. However, organic sediment accumulation primarily from Cattail colonization in the main pond has continued to increase impacting the pond’s primary function by reducing its capacity for water storage. Currently the water levels are at all-time highs as can be witnessed by the mature Ponderosa Pine Trucks underwater at the pond’s edge.

A recent environmental report commissioned by Campus Operations and Risk Management (2015) and has been reviewed by campus staff and select faculty. The report assessed the current conditions of the storm water retention system including associated wildlife and vegetation and provided several recommendations to restore storage capacity of the pond and an environmental maintenance plan for maintaining critical habitat features important to wildlife.

The recommendation accepted by Campus Operations to restore capacity of the main pond involves the removal of a 10 meter wide band of Cattails and associated organic and inorganic sediments on the Northeastern shoreline and the clearing of the forebay. Excavation work will begin the first week of January when most wildlife is either absent or in hibernation limiting potential negative impacts. To prevent further cattail colonization excavation will result in open water areas that are approximately 120 cm in depth during the growing season (excluding the forebay).

The maintenance on the pond is now complete.