Professional Civil Engineering Services
Expert Civil Engineering for Small-Scale Projects – Ensuring Compliance, Sustainability & Efficiency
As a licensed WA Professional Engineering firm (based in Bonney Lake/Tacoma area), we specialize in small site civil engineering compliant with the Washington State Department of Ecology's Stormwater Management Manual for Western Washington (SWMMWW, 2019 edition) and local adoptions like the Pierce County Stormwater Management and Site Development Manual (2020). Our focus is on sustainable, low-impact development for sites under 5 acres, addressing NPDES requirements, erosion control, and environmental protection.
We handle everything from concept to permit approval, integrating with structural engineering for seamless projects.
Small Site Civil Engineering Services
Stormwater Design & Management
Low-impact development (LID) plans including infiltration, bioretention, permeable pavements, detention ponds, and conveyance systems per Ecology SWMMWW and Pierce County manual. Flow control, water quality treatment, and runoff modeling.
SWPPP Preparation (Stormwater Pollution Prevention Plan)
Comprehensive SWPPPs for construction sites (required for disturbances ≥1 acre or per local thresholds), including erosion/sediment control BMPs, spill prevention, inspection protocols, and stabilization measures. Compliant with Ecology's Construction Stormwater General Permit.
Foundation Engineering & Geotechnical Support
Site-specific foundation designs (shallow/spread footings, piles), soil bearing capacity analysis, slope stability, and groundwater considerations – integrated with structural plans.
Utility Connections & Design
Sewer, water, stormwater, and dry utility (power, telecom) tie-ins; trench design, backfill specs, and coordination with utilities like Tacoma Public Utilities or Seattle Public Utilities.
Grading & Drainage Plans
Earthwork calculations, cut/fill balancing, site grading for positive drainage, erosion control, and ADA-compliant access.
Erosion & Sediment Control (ESC) Plans
Temporary and permanent measures like silt fences, check dams, and vegetated buffers for small sites.
Site Development & Permitting Support
Feasibility studies, critical area assessments (wetlands, steep slopes), and full civil sheets for permit submittal to jurisdictions like Pierce County Planning & Public Works or Seattle DPD.
Our Civil Engineering Process
- Initial Consultation – Review site plans, goals, regulations (Ecology/Pierce County manuals), and environmental constraints (virtual or on-site in South Sound).
- Site Investigation – Surveys, soil tests, hydrology data collection for accurate modeling.
- Design & Analysis – Use tools like WWHM or MGSFlood for stormwater modeling; prepare drawings, calcs, and reports.
- SWPPP & Documentation – Draft SWPPP narratives, BMP details, and compliance docs.
- Permit Submittal & Revisions – Submit to local agencies, address comments efficiently.
- Construction Support – Field observations, as-builts, and certification.
Why Choose Dow Engineering PLLC for Civil Engineering?
- Local Compliance Experts – In-depth knowledge of WA Ecology SWMMWW, Pierce County Stormwater Manual, and NPDES permits to avoid delays.
- Small Site Specialists – Focused on residential and small commercial for cost-effective, LID-friendly designs.
- Integrated Services – Seamless coordination with our structural engineering for one-stop solutions.
- Sustainable Focus – Emphasize green infrastructure to reduce runoff and qualify for incentives.
- Fast & Responsive – Quick revisions, direct PE involvement for reliable results.
- Affordable for Small Projects – Transparent pricing tailored to site scale.