Temporary Erosion & Sediment Control

A Temporary Erosion and Sediment Control (TESC) plan is required for all land disturbing activities requiring a clearing and grading permit, per SMC 15.20.070 as approved in Ordinance 1082. Exempt activities that do not require a clearing and grading permit still require the use of best management practices to control erosion and sedimentation that may result from such activities.

Amended Soil (BMP T5.13, 2005 Ecology Stormwater Management Manual for Western Washington) is required for all landscaped areas on all project sites 1 acre or larger. Amended soil is recommended for all landscaped areas on project sites smaller than 1 acre; the default BioRetention Soil Mix linked in the reference documents is recommended, though not required.

Note: A separate Department of Ecology Construction Stormwater General Permit is required for sites having 1 acre or more of disturbed area.

Modeling & Monitoring

For projects that clear 2,000 feet or greater, the City may require the ESC Supervisor to have a turbidity meter on-site. In addition to HSPF and KCRTS the Western Washington Hydrology Model is also an acceptable tool for continuous hydrology modeling.

Drainage Review Cost Estimate

The Figure 11 flow chart in the 2011 City of Snoqualmie Addendum will help determine which of the following four drainage review types a project must meet:

1. Small (e.g. individual lot) Project Drainage Review
2. Targeted Drainage Review (includes 3 different categories)
3. Full Drainage Review
4. Large Project Drainage Review (e.g. Master Drainage Plan)

Drainage plan review costs vary depending on project size, submittal quality (i.e. package completeness, clear TIR figures and writing, etc.), the number of re‐submittals, the analyses types included in the submittal, general project complexity, sensitive area proximity, and other factors. Accurate drainage review pricing is not possible prior to seeing an applicant’s submittal; the provided estimates are only to help provide some budgeting benchmark, and are not guarantees against additional resources needed for drainage review completion and plan approval.

The “typical cost” and “range of costs” are based on past reviews of that type within the City. The Full Drainage Review Project category has been split into the sub‐categories “Not Snoqualmie Ridge Infill Development” and “Snoqualmie Ridge Infill Development.”

Other Requirements

All projects must comply with applicable municipal codes, notably 15.18 Surface & Storm water and 15.20 Clearing and Grading code changes as approved in Ordinances 1081 & 1082, as well as the 2011 City of Snoqualmie Addendum. For maintenance and operations, applicable KCSWDM procedures should be used for guidance, but City specific requirements may be applied on a case by case basis. In addition to the KCSWDM requirements under Core Requirement number 7, there are specific City requirements for financial guarantees and liability noted in SMC 15.16.170.