Rainier Boulevard N LID Phase II
Green Stormwater Infrastructure Near Downtown Issaquah
When the City of Issaquah obtained a grant from the Washington State Department of Ecology to reconstruct Rainier Boulevard N., they asked KPG to design this section of roadway to blend seamlessly with the first phase of this project, which was designed by City engineers. This second phase included a roadway with permeable pavement and bioretention planters to infiltrate stormwater runoff and reduce stormwater related impacts to nearby Issaquah Creek.
The stormwater elements used in both phases of the project significantly reduced the amount of stormwater runoff, which allowed us to eliminate piped storm drainage in certain sections of the system. Certain sections included piped drainage, where we needed to provide an overflow in the event the infiltration systems become blocked.
In addition to these stormwater retrofits, KPG also designed a new multi-use trail along the east side of the roadway, new street illumination, landscaping, irrigation and undergrounding of existing overhead utilities. The landscape design preserved existing street trees and integrated seamlessly with recently completed improvements at Confluence Park.
Multiple public workshops were held and a technical advisory committee with the City was facilitated.