Meydenbauer Creek Bank Stabilization & Sewer

PBS worked with the City of Bellevue and Jacobs to obtain environmental permits for bank stabilization and replacement of a deteriorating sewer pipe near Lake Washington. Ongoing stream bank erosion in Meydenbauer Creek was threatening to expose City utilities, the City sidewalk, and an adjacent street. The existing sewer was not only very close to the eroding bank but in need of replacement. The project combined the sewer replacement with stabilization of the stream bank.

PBS conducted several site visits to identify the critical areas that could be affected by the project and to determine what permits would be necessary to maintain environmental compliance through the project. To obtain these permits, PBS conducted a critical areas assessment; wrote a Critical Areas Report, Stream Mitigation Plan, and Biological Evaluation; and performed an HEC-RAS model calculation for modifications of the stream channel.

PBS also assembled a JARPA application and SEPA documents to obtain the following required permits: Corps of Engineers 404 Nationwide Permits 13 and 33; a Hydraulic Project Approval (HPA), and a City of Bellevue Critical Areas Permit. Because of the limited space available, PBS suggested the use of a bioengineered stream bank made from Enviro-lok geotextile bags that would prevent further erosion and incorporate native plantings.

To assist the contractor in meeting all the permit conditions, PBS assembled a permit matrix that clearly identified environmental constraints during the design and construction of this project. We also provided follow-up permitting services during construction when the sewer installation necessitated modifications of the stream culverts.

Client:
City of Bellevue
Bellevue, Washington

Scope of Services:

  • Critical Areas Assessment
  • Environmental Permitting
  • Stream Mitigation Plan
  • Hydrogeology
  • Construction Oversight