A Seattle Street Improvement Permit (SIP) application needs a survey and base map of the affected right of way. Before fieldwork, the civil designer and surveyor should confirm the project limits, required control, topographic detail, drafting standards, and any adjacent features the design will use. A parcel-only topographic survey may leave the street design short of information.
Start with the permit path
Seattle DOT says most SIPs arise when adjacent development triggers street improvements. Its SIP permit overview explains the permit category. Confirm with the project’s civil engineer and SDOT whether a SIP applies and which current intake requirements govern; do not infer the answer from the property address alone.
SDOT’s Survey and Basemap applicant guide calls for a complete base map and survey as part of SIP work in the right of way. It identifies control, topographic survey, and base map components, with work prepared and stamped by a Washington-licensed surveyor.
Give the surveyor the design area, not only the lot
Send the current site and frontage plans, known permit conditions, anticipated work in the street, available records, and the current SDOT checklist. Ask the engineer to mark the limits that need grades, curb and sidewalk features, drainage structures, utilities visible at the surface, intersections, and adjoining context. The precise extent depends on the project and SDOT’s current requirements.
Agree on horizontal and vertical control, benchmarks, coordinate system, CAD format, and which features came from field measurement versus records. Utility lines shown from plans or locator markings should be labeled by source; their position should not be presented as physically verified without an appropriate separate investigation.
Check the handoff before detailed design
Have the engineer review an early base map for missing frontage features and unusable elevations. A technically accurate drawing can still be incomplete for the planned street improvements if the original scope omitted the area or datum the design requires. Record additions before the permit set advances.
Terrane’s Learning Center article on starting survey and engineering together covers the broader coordination. For the SIP assignment, send the current SDOT request, marked work limits, civil contact, available files, access constraints, and the date the base map must be ready for design.
The useful question is not “Do we have a topo?” It is whether the base map answers the right-of-way design and review questions for this permit.
