Updated Core Tap Procedures for Storm and Sewer Mains

Seattle Public Utilities (SPU) has updated their Core Tap Procedures for Storm and Sewer Mains web page to make it easier to understand. SPU also made updates to match their current practice for installing tees in a variety of pipe materials.

Some specific changes include:

  • A new table in section 4.5 that outlines the bedding materials required to restore support to the main at the core tap locations
  • New sections, such as:
    • Non-Standard Connections Process
    • Non-Standard Connections That SPU May Approve
    • Abandoning a Sewer Lateral at the Mainline


For more information, visit the Core Tap Procedures for Storm and Sewer Mains web page or contact the Development Services Office at spu_dso@seattle.gov or (206) 684‑3333.

Storm Drain Insert Reminder

–Builders Need to Inspect and Maintain Storm Drain “Socks”

With the onset of the rainy season, SDCI is reminding builders working in Seattle to inspect and maintain any temporary storm drain inserts they have installed as part of construction projects. The inserts, also known as storm drain socks, are used on many construction projects to catch sediment not captured by other required construction-related erosion control measures.

All construction sites must have on-site erosion control measures to prevent soil from washing away. The use of storm drain inserts is an added level of protection for water quality.

Stormwater Code standards for the use of the socks include the following:

  • Inspections by the builder should be made on a regular basis, especially after large storms. Inlet protection devices shall be cleaned or removed and replaced when sediment has filled one-third of the available storage. Product manufacturer standards should be followed.
  • Do not wash sediment into storm drains while cleaning. Spread all excavated material evenly over the surrounding land area or stockpile and stabilize as appropriate.
  • Only place the storm drain inserts in the area directly adjacent to the project site.
  • In the event of heavy rain, remove the socks to prevent local flooding.


For reference, see SDCI Director’s Rule 17-2017, SPU DWW-200, Stormwater Manual, Volume 2, Chapter 4, Section 4.3.3.

Any questions on active construction site drainage or erosion control measures may be referred to the SDCI Site Inspection Team at (206) 684-8600.

To help prevent flooding, the public is urged to clear clogged drains where it is safe and practical to do so. Flooding should be reported to Seattle Public Utilities at (206) 386-1800.

Publication Updates



  • Tip 107, SDCI Public Records, with information about the Public Records Request Center. We streamlined the information about electronic records and the microfilm library.
  • Tip 309, Blanket Permits, with new the new application process. Copies are available online and in the ASC.


Director’s Rules




GSI Summit Focuses on ‘Getting Growth Right’

The Office of Sustainability & Environment is pleased to again be sponsoring and serving on the host committee for our region’s 2nd annual day-long Green Infrastructure Summit, taking place on Thursday, February 16th at the Mountaineers Club.

The Summit, convened by Stewardship Partners, will bring together  thought leaders from government, academia, business, and the non-profit sector to share models for innovation and strategize on intersectional green solutions to stormwater pollution – solutions that improve neighborhoods, help us prepare for climate change, and further racial equity in our communities during this time of intense growth across the region.

This year, Summit organizers are thrilled to welcome MacArthur Genius award-winner, Majora Carter, as the event’s keynote speaker and Seattle Public Utilities’ new director, Mami Hara, as its closing speaker. There is still time to register!  Visit  www.12000raingardens.org/summit/  for additional information. We look forward to seeing you on the 16th!

Updated – Are YOU Prepared for Landslides?

–Wetter conditions expected this winter

Did you know that most landslides occur between the months of November and March? Or that Seattle just set a record for the most rainfall ever in the month of October? As rainfall continues to increase throughout the fall, the threat of landslides will continue to rise this winter.

Landslide season is upon us, so the City of Seattle is urging residents to take preventive measures to protect themselves and their property from possible landslides.

Most landslides are caused by water (e.g. rainfall, uncontrolled stormwater) or human activity that increases the weight at the top of the slope or reduces the stability at the bottom of the slope.

With 20,000 Seattle properties (mostly residential) in landslide-prone areas, the Seattle’s Department of Construction and Inspections (Seattle DCI) encourages property owners to take preventive measures to protect themselves from landslides by:

  • Checking downspouts; making sure they are functioning/routed to a safe location
  • Maintaining drainage systems by clearing away leaves and debris
  • Inspecting sloped areas for indications of soil movement and erosion
  • Shutting off irrigation systems and checking it out seasonally
  • Keeping fill and yard waste off slopes
  • Knowing when to seek professional help for hillside projects

Visit our website to understand if you’re at risk and how to be prepared. Helpful tools include:

  • Landslide tutorial
  • Interactive GIS Map
  • Landslide Prone Area Map
  • Do’s & Don’ts

If a landslide damages your property and you have an immediate concern for your safety, leave the premises and call 9-1-1. Seattle property owners with structures that may be affected or endangered by a landslide should also contact Seattle DCI at (206) 615-0808 so that a building inspector can respond and perform an initial assessment of the structure.

To view the current conditions of the USGS rainfall threshold for landslides, please visit: http://landslides.usgs.gov/monitoring/seattle/rtd/plot.php.