Assured Water Supply

Overview

The City of Boise is committed to supporting sustainable growth that aligns with our natural water resources. The Assured Water Supply standards are intended to provide protection and benefits to residents, the development community, designated water providers, and other regulatory agencies by ensuring that growth and land development aligns with long-term water supply needs.

These standards begin July 1, 2024 and apply to development on previously undeveloped lands, or any proposed redevelopment that includes the creation of five or more total dwelling units or is in specific critical areas determined by state statutes, unless specifically accepted in accordance with the zoning code. These standards are in place to supplement the roles and responsibilities of State of Idaho's water supply regulators solely for planning and zoning purposes, to confirm that water resources will be available to serve continued growth in Boise. These standards are not intended, however, to conflict or duplicate efforts of any state agencies that regulate the water supply. Based on the Local Land Use Planning Act (LLUPA), the city will consider the impact of development on water supply and water quality.

Read the Code

Elements of Demonstrating Assured Water Supply

Every provider of water for drinking or general domestic use as a public utility within the city limits or the City Area of Impact is required to be certified as a Designated Water Provider by demonstrating it has an Assured Water Supply and be approved by the Planning Director a designee based on the criteria in the zoning code.

To demonstrate an assured water supply, the criteria outlined in the zoning code will be analyzed based on reasonable population projections with in the existing service area, including:

• Physical and legal water availability
• Continuous water availability
• Adequate delivery and quality; and
• Compliance with GMD, CGA, GMA, and ARD Standards

Proof of Assured Water Supply Required

The proof of an assured water supply may be provided by:

• A letter from a Designated Water Provider committing all or a portion of its Assured Water Supply to meet the anticipated water demand or
• Information and analysis from the applicant, prepared and submitted at the applicant's expense, confirming an Assured Water Supply for project completion.

All licensure requirements of Idaho State Code must also be followed by the applicant where applicable for the submission information.

Representations

The appropriate city form must be submitted by the Designated Water Provider or the applicant attesting that:

• The information is true and complete to the best of their knowledge
• The representations are binding upon the signing party and its successors in interest; and
• The individual executing the letter or analysis, as applicable, has any and all required authorization to submit the materials.

Certification and Required Recertification

After the application is reviewed and approved, the proof of Assured Water Supply must be recertified by either the Designated Water Provider or the applicant. The Designated Water Provider must recertify if:

• More than 10 years have passed since the approval;
• The Designated Water Provider applies to enlarge its certified service area; or
• The city has experienced extreme or exceptional drought, according to the United States Drought Monitor, for a majority of months within each calendar year for a period of three consecutive years.

The applicant must recertify if:

• More than 10 years have passed since the approval;
• The project, has changed in scope in a way that also changes the type or intensity of the water demand; or
• The city has experienced extreme or exceptional drought, according to the United States Drought Monitor, for a majority of months within each calendar year for a period of three consecutive years.

Assured Water Supply Implementation Guidance Document and Application(s)

A guidance document and application forms to support the implementation of the Assured Water Supply requirements have been developed for use by Designated Water Providers and development applicants.

Assured Water Supply Implementation Guide

Application B: Applicants seeking AWS for development within a Designated Water Provider’s service area.

Assured Water Supply Application B

Application C: Applicants seeking AWS for onsite Private Water Systems.

Assured Water Supply Application C

Demand Calculator is a tool that can be used to aid applicants in calculating the water demand for a proposed project.

Demand Calculator

AWS Flowchart is a tool to help applicants determine whether AWS will be required for their project.

Assured Water Supply Flowchart