Stormwater permits in City of Issaquah: fees, timeline & requirements (2026)
Everything you need to know about pulling a stormwater / drainage permit in City of Issaquah, Washington — when one is required, what it costs, how long review takes, what documents are required, and which inspections you can expect. Cited to Community Planning & Development.
Free lookup, no account needed — your lot polygon, zoning, setbacks and overlays, cited to City of Issaquah's source.
When does a stormwater / drainage need a permit in City of Issaquah?
Ecology's Stormwater Management Manual for Western Washington (SWMMWW, 2024 edition) is the state floor. A municipal stormwater permittee may instead adopt a REGIONAL manual Ecology has determined equivalent, and most do — some counties publish their own, some cities publish their own, and others adopt Ecology's directly. WHICH MANUAL APPLIES IS A PER-JURISDICTION FACT and it changes the numbers: review thresholds for new plus replaced impervious surface and for land-disturbing activity differ between manuals, so read this jurisdiction's own adopting chapter before quoting one. Critical-area and closed-basin parcels get stricter review under every manual.
From City of Issaquah's own code
“A. Permit Required. Any land disturbing activity that involves clearing, grading, or creation or modification of a stormwater management facility requires approved plans and permit(s), unless such activity is determined to be exempt from obtaining a permit as provided below.”Source ↗verified 2026-09-06
What City of Issaquah says in its own permit handout
From 2017 City of Issaquah Stormwater Addendum, published by City of Issaquah. This is the jurisdiction's own guidance on its permit process, not the ordinance text — where the two differ, the code governs.
“TESC plan review is required even if the applicant is also required to obtain an Ecology Construction Stormwater General Permit.”Handout ↗read 2026-09-05
Required submittals
- drainage report (full or simplified)
- site plan with impervious calc
- BMP / facility detail
- geotech if infiltration claimed
Inspection sequence
- pre-construction (BMPs in place)
- facility installation
- final stabilization
Contractor specialties needed
general
Who can do this work in City of Issaquah?
Kolmo Construction is a licensed Washington general contractor — KOLMOL*753JS, active through April 10, 2027, bonded and insured — working throughout City of Issaquah and King County. Kolmo prepares the drawings and submittals, files the stormwater / drainage permit with Community Planning & Development, carries the project through review and inspections, and performs the construction. Call (206) 410-5100 for a City of Issaquah stormwater / drainage quote.
Notes & caveats
Issuing body is city public works / county DPER, often parallel to the building permit. On-site infiltration / detention required where infeasible to discharge to municipal storm. Critical-area parcels (steep slope, salmon-bearing watercourse) get more conservative review.
How to apply yourself
- 1. Confirm your parcel's zoning & overlays. Run an address lookup for your City of Issaquah stormwater / drainage — we'll pull your specific lot polygon, zoning, setbacks, and any shoreline/ECA/historic overlays.
- 2. Assemble submittals (4).
- 3. Submit through the city portal: Community Planning & Development ↗
- 4. Track review. Respond to reviewer comments promptly.
- 5. Pay issuance fees (Drainage review fees are commonly tiered by project size in the city's fee schedule. Apply via https://mybuildingpermit.com.) and pick up the permit. Inspection card travels with the job.
Or have Kolmo do it
We pull stormwater / drainage permits in City of Issaquah every month. We prepare the drawings and submittals, file with Community Planning & Development, handle reviewer comments, and build the project.
Licensed WA general contractor KOLMOL*753JS · bonded & insured
Stormwater permits in City of Issaquah — FAQ
When does a stormwater / drainage need a permit in City of Issaquah?
Ecology's Stormwater Management Manual for Western Washington (SWMMWW, 2024 edition) is the state floor. A municipal stormwater permittee may instead adopt a REGIONAL manual Ecology has determined equivalent, and most do — some counties publish their own, some cities publish their own, and others adopt Ecology's directly. WHICH MANUAL APPLIES IS A PER-JURISDICTION FACT and it changes the numbers: review thresholds for new plus replaced impervious surface and for land-disturbing activity differ between manuals, so read this jurisdiction's own adopting chapter before quoting one. Critical-area and closed-basin parcels get stricter review under every manual.
How much does a stormwater / drainage permit cost in City of Issaquah?
Current fee per the City of Issaquah fee schedule: Drainage review fees are commonly tiered by project size in the city's fee schedule. Apply via https://mybuildingpermit.com.. Plus ancillary plan-review/tech-surcharge fees per city schedule.