The primary focus of construction stormwater planning is to prevent sediment and other pollutants associated with construction activity from impacting soil, air, and water quality. Such impacts can increase project costs through regulatory and legal fines, and through repair of site damage that causes delays to project delivery.

The Stormwater, Grading and Drainage Control Code (SMC 22.800-22.808) and associated Directors’ Rules are being revised to account for advances in urban stormwater runoff management practices. These regulations are in place to protect life, property, public health and the environment from the adverse impacts of urban stormwater runoff. Adverse impacts can include flooding, pollution, landslides and erosion.

These code and Director’s rule requirements are currently being reviewed and revised, it will be the responsibility of the developer to adhere to the mandated requirements. Changes and updates to the code are being made to make it equivalent to the 2005 Washington Department of Ecology’s Stormwater Management Manual for Western Washington. This is a requirement for compliance with the Municipal Stormwater NPDES Permit, which was issued January 17, 2007.

Temporary erosion and sediment control (TESC) and spill prevention control and countermeasures (SPCC) plans are required to adequately and systematically identify and minimize project risk. Together, the TESC and SPCC plans satisfy the construction stormwater pollution prevention requirements for all projects that require stormwater site plans. All projects that disturb soil must comply with the TESC elements, and apply appropriate best management practices (BMPs).

In 2000, t he City of Seattle has adopted a set of BMPs for TESC. The Seattle Municipal Code (SMC) 22.800 through 22.808 fully defines these BMPS, as does Department of Planning and Development (DPD) Director's Rule 16-00: Volume 2: Construction Stormwater Control Technical Requirements Manual. In addition to these documents, refer to Standard Specification 1-07-15: Temporary Water Pollution and Sediment Control, with emphasis on Sections 1-05.3(3), 1-07.16(2) and 8-01.

Additional resources for standard details include Standard Plans for tree protection 132, 133, and 134, as well as DPD standard plans under the Building Permit Forms section.