HomeMy WebLinkAboutTetra Tech PresentationContract with Tetra Tech, Inc. for
Engineering Services
Big Soos Creek at 116 th
Ave SE Sediment Control
March 2, 2026
Kevin Evans, P.E.,
Civil Engineer III
Surface Water Utility
Location:
•116th Ave SE between SE 168th St
and Petrovitsky Road
Big Soos Creek at 116th Ave SE Sediment Control
Project Background
Big Soos Creek Outfall under 116th Ave SE
Problems:
•Significant sedimentation has been observed in the Big
Soos Creek channel from 116th Ave SE to SE Petrovitsky
Road.
•Big Soos Creek runs through private property, making it
difficult to maintain.
•Excessive vegetation growth and reduced conveyance
capacity of the channel increase risk of flooding.
•Proposed Soos Creek Watershed fine sediment Total
Maximum Daily Load limit (TMDL) compels Renton to
reduce peak flows and fine sediment discharge to Big Soos
Creek.
Big Soos Creek at 116th Ave SE Sediment Control
Project Background
Vicinity Map
Project Objectives:
•Investigating sediment sources and inputs into
the stream within the basin at and upstream of 116th
Ave SE.
•Significantly reduce sediment deposition in the
channel to decrease flood risk in the surrounding
area.
•Improve the channel’s flow conveyance capacity of
Big Soos Creek in the project area.
•Reduce the City’s long-term maintenance burden in
the project area.
•Meet TMDL requirements, with site-specific data
collection, subwatershed modeling, and
implementation of stormwater best management
practices (BMPs).
Big Soos Creek at 116th Ave SE Sediment Control
Project Objectives
Big Soos Creek Running Through Private Properties
Big Soos Creek at 116th Ave SE Sediment Control
Contract Overview
Consultant Selection:
•Reviewed SOQs from 10 engineering firm on MRSC
Roster
•Interviewed four top scoring firms
•Tetra Tech Inc. was selected as most qualified firm to
provide engineering services
Contract Phasing:
•Phase 1 – Initial Evaluation and Conclusions, 30%
Design
•Phase 2 – Design and Permit Support (Future
Amendment)
•Phase 3 – Bid Support and Services During
Construction (Future Amendment)
Big Soos Creek Culvert Under 118th Ave SE
Big Soos Creek at 116th Ave SE Sediment Control
Scope of Work
Scope of Services: Consultant work will include:
•Project Management
•Data Collection and Review
•GIS data, as-builts, Soos Creek Fine Sediments TMDL, site
reconnaissance, and stormwater sampling
•Preliminary Survey
•Hydrologic Evaluation
•Will support identification of sediment accumulation
hotspots
•Alternatives Analysis
•30% Design of Stormwater Improvements
•Permit Pathway Review
116th Ave SE Near Big Soos Creek looking North
Big Soos Creek at 116th Ave SE Sediment Control
Project Schedule
Planning Level Project Schedule:
•Q1 2026: Data collection and review, preliminary survey
•Q2 2026: Hydrologic evaluation and stormwater memo
•Q3 2026: Alternatives analysis
•Q4 2026: Initiate 30% Design plans and cost estimate,
permit pathway review
Big Soos Creek from 116th Ave SE
Recommendation to
Utilities Committee
Staff Recommendation
Authorize the Mayor and City Clerk to
execute the agreement with Tetra Tech,
Inc. for engineering services for the Big
Soos Creek at 116th Ave SE Sediment
Control project.
Fiscal Impact
Sufficient funding is available in the
approved 2026 project budget to fund the
contract amount of $289,671.
Budget for the Big Soos Creek at 116th Ave
SE Sediment Control project (427.475614)
is $500,000 as of March 2026.