Development Application Reviews

Development applications received by HD4 are reviewed on a first-come-first-served basis subject to adjustments for the application type and number of submittals as follows:

Review Score  =  (# of days since receipt) x (Application Type Multiplier) x (Submittal Multiplier)

Application Multiplier:  Concept (1.0);  Prelim Plat (1.25);  Improvement Dwg (1.5);  Final Plat (2.0)

Submittal Multiplier:  1st (1.0);  2nd (4.0);  3rd (9.0);  4th (1.5);  5th (1.2);  6th or higher (1.0)

Applications with the highest review score are reviewed first. This prioritization for project review is intended to promote faster reviews as projects advance beyond the preliminary entitlement stages, and to significantly reduce review times for 2nd and 3rd submittals to advance projects to the next stage once they are under review.  Applications that require multiple reviews (4 or more) to meet development standards are subject to reduced review priority to encourage applicants to carefully review previous comments and the published development standards.

Open Letter to the Development Community

Please see the letter below regarding development plan reviews and review priorities:


Development Review Letter July 8, 2021 276.14 KB 1172 downloads


Master Development Application 

A  Master Development Application is required with all development-related submittals to allow tracking of applications and to assist in review prioritization.  Please include this completed form with all project inquiries or submittals.

2022 Highway Standards and Development Procedures Manual  (HSDP Manual)

(2022 Edition) Development design standards, policies, and submittal requirements are provided in detail in the Highway Standards and Development Procedures Manual, which has been adopted by all four highway districts in Canyon County.

  • Section 1:   Introduction
  • Section 2:   General Development Procedures and Conditions
  • Section 3:   Design Standards
  • Section 4:   Supplemental Specifications to the Idaho Standards for Public Works Construction
  • Section 5:   Construction Quality Assurance and Project Closeout
  • Section 6:   Definitions
  • Appendicies:   Standard Forms and Standard Drawings

Administrative Land Division or Lot Line Adjustment

HD4 will review and provide a Letter of Acknowledgement for Administrative Land Divisions or Lot Line Adjustments authorized under County Code.  Please include the following information to HD4 to allow for prompt review:

  • Master Development Application
  • Completed parcel inquiry form from Canyon County confirming the number of splits available and other entitlements.
  • Letter of Acknowledgement form from Canyon County with property owner's name, contact information, property address, and parcel number.
  • Site plan or preliminary record of survey showing original parcel boundary and proposed division(s).
  • Evidence of recorded easement if proposed for use, or if there is no public roadway frontage for the parcel.

A $250 application fee is required at the time of application.  HD4 will evaluate existing and proposed access locations to serve the property, and may require access restrictions, access improvments, or right-of-way dedication as conditions of approval.  Access standards are determined in accordance with Section 3061 of the HSDP Manual.  Review times vary with the availability of staff and the complexity of the request, but are typically 7 - 14 days.

Pre-Development Review or Entitlement Inquiry

Preliminary development reviews are provided by appointment only.  Please contact the office at 208-454-8135 to schedule an appointment.  Appointments are limited to 30 minutes and are available on a first-come, first-served basis.  To assist in a thorough review, please provde the following information at the time the appointment is made:

  • Master Development Application (required to make an appointment).
  • Project owner or representative, including contact information
  • Vicinity Map including street names, property address, or parcel number(s)
  • Development Type (Residential, High Density Residential, Commercial, etc...)
  • Proposed Development Density or Commercial Business Type

HD4 will review and provide information on the current and planned transportation system affecting the property, right-of-way widths, access availability or restrictions, anticipated development requirments, traffic impact studies, or other policies that may affect the proposed land use change.

Preliminary Plat

Preliminary Plats are approved by the HD4 Board of Commissioners.  Board meetings are held every other week, typically on Wednesday during business hours.  Completed preliminary plat applications must be received a minimum of two weeks prior to the requested hearing date to be considered for a Board agenda.  Please include the following information with any preliminary plat submittal:

  • Master Development Application
  • Preliminary Plat (full size hard copy and electronic copy) and submittals meeting Canyon County and HSDP Section 2030 requirements
  • Completed Preliminary Plat Checklist
  • Traffic Impact Study
  • Approval letter from City if within area of impact
  • Preliminary Plat Review Fee:   $200 + $6 per buildable lot


CHD4 Preliminary Plat Review Checklist 116.16 KB 3959 downloads


The HD4 Board will review and approve the following general conditions at preliminary plat stage:  access type and location, current and future transportation needs, connectivity, right-of-way dedication, improvement requirements (including urban infrastructure within areas of impact), and mitigation of traffic impacts.

Improvement Drawings

Improvement plan reviews are conducted in the order received, with priority given to re-submittals or change orders.  Please include the following information with any improvement drawing submittal:

  • Master Development Application
  • Improvement Plan submittals meeting HSDP Section 2030.04 requirements  (single hard copy and electronic copy)
  •  Final Plat (all sheets) if applicable (single hard copy and electronic copy)
  • Completed Improvement Plan Checklist
  • Drainage Report and Calculations
  • Geotechnical Report and Pavement Design Calculations
  • SWPPP Plan and Narrative  (electronic copy only)
  • Improvement Plan Review Fee:   $450 + $15 per buildable lot for projects in Canyon County;  $200 flat fee for city or other agency projects that affect roads maintained by CHD4.


CHD4 Plan Review Checklist 218.75 KB 4999 downloads


Incomplete submittals may be returned for correction without review.  No permits for roadway or utility construction within public right-of-way, or on roadways intended for dedication as public streets will be issued until improvement plans have been reviewed and accepted for construction by HD4.

Final Plat

HD4 requires construction of public roadway improvements, including drainage works or offsite traffic mitigation, prior to final plat approval.  Final plats are approved by the HD4 Board of Commissioners.  Board meetings are typically held every other Wednesday during business hours.  Final plat applications, including project closeout and construction certification documents must be received a minimum of two weeks prior to the requested hearing date to be placed on the agenda. Please include the following information with any final plat submittal:

  • Master Development Application
  • Final Plat (one full size hard copy and electronic copy)
  • Completed Final Plat Review Checklist
  • Final PlatReview Fee:   $300 + $20 per buildable lot
  • Project Closeout Package:   Engineer's Construction Observation Reports, Copies of all Testing Reports, Record Drawings, Engineer's Certification Statement, Request for Acceptance of Road Improvments, Construction Surety or Warranty Bond (50% of improvement costs), Signed Financial Guarantee Agreement, Signed License Agreement for Irrigation or Landscaping, Construction Punchlist completed and approved by CHD4.  See HSDP Section 5000.

The mylar original plat should be available for signature at the Board Meeting where the plat is considered.


CHD4 Plat Review Checklist 97.10 KB 5683 downloads


Pre- and Post- Development Stormwater Supplemental Standards

Standards for stormwater treatment and disposal are found in the HSDP Manual Section 3070.  The Supplemental Stormwater Standards address requirements for SWPPP plans during construction, and additional requirements for permanent stormwater controls for projects that discharge to the MS4 drainage system operated by HD4.