5900 36TH AVE W SEPA 015 - 034 - SOUNDVIEW BUSINESS CAMPUS - VERITAS Land Use Decision Documents 2025-04-22

Downstream Analysis PACLAND-Bellevue previously conducted a downstream analysis for the Soundview project on May 13, 2005 along with further reconnaissance January 2006. Downstream analysis included visual, quantitative and qualitative review as required by the City of Everett. PACLAND-Bellevue performed an additional analysis and site walk of the downstream conditions on October 8, 2016 to determine if significant changes have occurred since the original downstream analysis. The Soundview project will release storm water to three (3) separate sub -basins. The following downstream summaries include the original descriptions from 2005 and 2006 with revised or additional information inserted in bold for clarity. Basin A: 10/9/15 Update: There have been no apparent changes to the downstream system since the first analysis in 2005/2006. The western portion of the site drains into Japanese Gulch. The natural drainage flows down to the forest valley which continues to the bottom of Japanese Gulch, where it intersects the Burlington Northern Railroad Spur. The average slope of this large forest valley is approximately 10-20% with portions near the top greater than 40%. Existing flows intersect the railroad bed and are conveyed underneath the railroad bed by a 24" reinforced concrete pipe. (See below). alit Soundview Preliminary Downstream Analysis