2115 NE 130th St, Seattle, WA 98125

Applicant: Yunyan & Lenna Xie • Assessed Value: $780,000

Professional Attestation & Digital Stamp Applied

Dossier certified under SMC 25.09.012(C)(2)(a) Artificial Wetland Exclusion. Ready for formal municipal hearing submission.

Discovered Spatial & Municipal Files (1)

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LAS PointCloud13.87 MB

pointcloud_classified_vegetation.las

USGS 3DEP Classified LiDAR Point Cloud (Ground / Low / High Veg)

Part 1: Statutory Authority

Formal Memo

Active Citation: SMC 25.09.012(C)(2)(a) Artificial Wetland Exclusion

Reviewer: Christy Carr (Seattle Department of Construction & Inspections (SDCI))

"Critical Areas screening flagged potential wetland in excavated NW pond/ditch swale. Requires 110-ft buffer unless artificial upland origin proven."

Binding Precedent: Under *Madison Estates v. Seattle SDCI* (CoA Div 1 No. 85733-9-I), documented mechanical excavation and highway grading establish statutory upland exclusion regardless of intermittent ponding or secondary hydric soil indicators.

Part 2: Aerial Chronology

1940–2025

1940 Baseline

Undisturbed upland agricultural field; zero surface water or channel signature.

1965 Highway Cut

Adjacent road grading underway; mechanical spoil berms and artificial cut visible.

1995 Runoff Swale

Excavated drainage ditch conveying highway runoff; no downstream natural confluence.

2025 Current Ortho

Point-source municipal outfall conduit headwall in active MS4 drainage service.

Part 3: Bare-Earth LiDAR

1-ft Contours

Elevation Datum:480.7 – 491.4 ft

4-Sun Hillshade:0°, 90°, 180°, 270°

Morphology:2.5:1 Spoil Berms

Cross-section profiles confirm straight-walled, flat-bottom geometry diagnostic of machine excavation, lacking the meandering sinuosity of natural wetlands.

Part 4: MS4 Connectivity

Hydraulic Trace

Asset Ownership:PUBLIC_MUNICIPAL

Upstream Culverts:2 active 18-inch CMP

NRCS Soil Series:Anthropogenic Fill

Hydraulic grade-line tracing demonstrates the swale is a point-source conduit for public street stormwater, exempting it from natural tributary buffer designations.

Professional Review Attestation

Professional Wetland Scientist (PWS) / Professional Engineer (PE)

"I have reviewed the USGS 3DEP topography, aerial orthophotos, and municipal GIS records compiled herein. The feature satisfies the statutory requirements for complete exclusion from municipal critical area buffers."

Verified Digital Hash: SHA256-78b941a3d02e • Stamped: 2026-09-04