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Planning project · Planning application

Block retaining wall proposed to replace railroad tie wall on hillside lot

The city treats the project as a Category II hillside review because of slope and unstable soils. A geotechnical report and engineering plans may be required. Staff would decide the application administratively.

SubmittedPLN26-00760Filed Aug. 12, 2026488 W Sandstone Ct+1 related filing
Site plan for Block retaining wall proposed to replace railroad tie wall on hillside lot
Site plan from the application documents.
Pin at the reported location; the shaded outline is the primary parcel (Ada County).

From the filing

The application's description as it appears in City of Boise's record. See the official record

Cat II

Project name on file: 488 W SANDSTONE CT

Timeline

  1. Oct. 13, 2026

    10 documents added

  2. Aug. 18, 2026

    Concept Review Complete: Engineering Preview

  3. Aug. 18, 2026

    Concept Review Complete: Engineering Preview Complete

    Based on submitted documents and limited overview of the property, a determination has been made that this project will be a Category II Hillside project due to slope, erosion-prone soils, unstable soils, earth movement, and other geologic and hydrologic hazards. In addition to the already submitted documents (please submit them with subsequent applications), additional documents may be required during the CFH Review process.Additional documents that you can expect to provide will be a site-specific geotechnical report with the possibility of a global slope stability analysis (please see the Agency Comment for Hillside Retaining Wall Permitting within this PLN); structural calculations for any retaining wall system that is greater than four feet in height from top of foundation to top of wall, that has more than one wall when the interior horizontal distance between the walls is less than 10 feet and the total height of all walls exceeds four feet, that has a surcharge, that has a backslope greater than three feet horizontal to one foot vertical, or that has structural components (these requirements will be assessed again at the time of occupancy); and civil plans. Please refer to the Hillside Development Requirements for Technical Reports for grading & drainage plan and geotechnical report requirements.A subgrade inspection by a geotechnical firm will be required at the time of construction once the subgrade is exposed and prior to placement of foundation materials or forms/rebar. A report of the inspection will need to be submitted to and accepted by PW Hillside (HillsideDrainage@cityofboise.org) before scheduling your inspection with the Building Department and receiving final occupancy.NOTE: The hazards of developing and building on a property, especially in the Boise foothills, are well known. It is the responsibility of the applicant/owner’s design, geological, and engineering professionals, not the City, to identify, address, and mitigate any hazards to the site. Satisfying these Conditions of Approval is for limited [City purpose] only and should not be relied on for design, geological or engineering purposes. Developer will comply with all requirements of Boise City Hillside Development Code Sections or submit evidence satisfactory to the Boise City Engineer that the proposed development is exempt from the requirements therein stated due to location, topography and/or the absence of adverse conditions associated with slope stability, ground water, erosion and sedimentation.If you would like to discuss this determination, please contact us at HillsideDrainage@cityofboise.org. Please include your application number and address in the subject line.

  4. Aug. 18, 2026

    Concept Review Complete: CR Complete - Type 2

  5. Aug. 14, 2026

    Concept Review Complete: Hillside Questionnaire Needed

  6. Aug. 12, 2026

    Application Submittal: Online

  7. Aug. 12, 2026

    Application filed

Documents

Plans

  • Residence landscaping plan showing plant materials legend, hardscape such as pavers, retaining walls, steps and a fire pit, with a scale and designer information.

    Aug. 18, 2026 · 1 page · 18.4 MB · PDS-Other Small Docs

    Download Landscape plan with measurements and planting details
  • Residence landscaping plan showing plant materials legend, hardscape such as pavers, retaining walls, steps and a fire pit, with a scale and designer information.

    Aug. 18, 2026 · 1 page · 18.4 MB · PDS-Other Small Docs

    Download Landscape plan with measurements and planting details

Project narrative

  • Advisory concept review summary for a planned replacement of a railroad tie wall with a block wall, classifying the project as a Category II hillside project and listing expected technical documents.

    Aug. 18, 2026 · 2 pages · 452 KB · PDS-Concept Review Summary Report

    Download Concept review summary report

Application

  • Application to replace an existing railroad tie retaining wall with a block wall on an R-1A zoned residential lot, with applicant, owner and hillside questionnaire details.

    Aug. 12, 2026 · 2 pages · 154 KB · PDS-Application

    Download Planning project application form

Photos

Correspondence

  • Public Works guidance on when retaining walls in the hillside zone need a determination, slope stability analysis, and planning-code height and setback limits.

    Aug. 18, 2026 · 5 pages · 804 KB · PDS-Agency Comments

    Download Hillside retaining wall permitting guidance

Other documents

Nearby

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