Regina shoreline sewage lagoon, Regina, Sask., Canada
When Stantec Consulting Ltd. of Regina, SK, Canada, won the contract to design a new sewage lagoon for the City of Regina, the site’s history provided a good indication that serious erosion control measures were called for. Constructed in the early 1960s, the Regina Wastewater Treatment Plan uses a series of lagoons to contain secondary effluent from its sewage treatment operation. With the use of native clay soi1 as a containment medium and built with no shoreline protection system, the original lagoons soon began to erode from wind-induced wave action. A few years after their construction, their interior slopes were shored up with reclaimed sections of concrete from sidewalks and roads placed along the lagoons’ top 3 m. Poured concrete was added to protect the slopes’ lower portions. This hard-armor solution was only partially effective. The areas of concrete rubble at the tops of the slopes permitted extensive vegetation growth and were difficult for treatment plant operations crews to access. The poured concrete sections cracked and because they were not restrained tended to slide downslope.