osborne-squareOsborne Square – Snohomish County, Washington

Afton Properties

Osborne Square is a new commercial retail mall at the intersection of 132nd Street SE (SR96) and Seattle Hill Road.  Existing site was an unapproved detention pond built by the county in the 1980’s.

Design required extensive coordination with Snohomish County and WSDOT to establish the upstream basin (approximately 70 acres), research the history of the pond. establish flow control and water quality parameters and design a dual system that met all necessary requirements of Snohomish County and WSDOT.  Design also included water and sewer design through Silver Lake water and Sewer District, retaining walls along the back of the project, storm drainage improvements in public roads downstream of the project and improvements along the site frontages to 132nd and Seattle Hill Road along with new intersection channelization to WSDOT standards.  Project also included a traffic concurrency requirement for a right-turn lane extension at another intersection 1 mile from the project site.