Client: City of Tigard, Oregon
The City of Tigard was required to create approximately 5 acres of new wetlands to mitigate for various wetland impacts associated with expansion of Cook Park and other projects.
CESNW provided surveying for the topographic mapping and construction staking; civil engineering for the grading and utility plans; and preparation of landscaping/planting plans. The construction plans were based on implementing the DSL/COE wetland permit requirements.
The project involved removing 30,000 cubic yards of dirt and specific grading to create the desired planting areas and various water depths. The storm sewer overflow system included a bored outfall to the Tualatin River to reduce impacts to the river bank and existing vegetation.
The design also included incorporating Class 4 Reclaimed Water from the Clean Water Services Durham Treatment plant for temporary irrigation and to maintain summertime wetland water levels. The reclaimed water system was designed to automatically maintain water levels in the wetland area.