Washington projects are typically governed by the Department of Ecology’s Stormwater Management Manuals for Western Washington (SWMMWW) or Eastern Washington (SWMMEW), depending on location. Many local jurisdictions—such as King, Pierce, and Snohomish counties—also have their own adopted standards that add requirements beyond the state minimums. We review the applicable manual and any local amendments at the start of every project to ensure your site is fully compliant.

Most projects that create or replace 2,000 square feet or more of impervious surface will require a stormwater management plan under Department of Ecology regulations. Projects adding 5,000 square feet or more typically require full stormwater design, which is usually prepared by a licensed civil engineer. Smaller projects may still require engineering depending on the jurisdiction. We review these thresholds early and design a site-specific approach to meet the applicable requirements.

A Stormwater Pollution Prevention Plan (SWPPP) outlines how a construction site will prevent sediment and pollutants from leaving the site during construction. In Washington, most projects that require a stormwater management plan will also need a SWPPP. Larger projects that disturb one acre or more must also obtain coverage under the Department of Ecology’s Construction Stormwater General Permit. We prepare project-specific SWPPPs and design the appropriate erosion and sediment control measures to keep your project compliant.

We design water, sanitary sewer, and dry utility systems—including coordination with power, gas, and telecom providers—for residential, commercial, and mixed-use developments. Our services include hydraulic modeling, profile design, utility conflict coordination, and preparation of construction documents that meet local utility district and WSDOT standards.

To get started on a proposal for your project, we typically need the project address or parcel number, a brief description of the proposed development (such as use, building footprint, and site coverage), and your timeline. Any existing survey or topographic information is helpful, and site plans or preliminary architectural drawings are a bonus—but not required at the proposal stage.

Timelines vary based on project complexity and jurisdiction. Simpler residential or commercial projects may move through design and permitting in 3–6 months, while larger or more complex projects—especially those involving environmental review, utility extensions, or SEPA—can take 12–24 months or more.

We provide project-specific schedule estimates early on and keep you informed throughout the process. Because we maintain a focused workload, have deep familiarity with local permitting requirements and stormwater regulations, and operate with low overhead, we’re often able to complete design work more efficiently than larger firms.