Bozeman is a fast-growing drought-prone community facing numerous water supply constraints posed by its headwaters location in the Upper Missouri River Watershed, impacts of climate change on water supply yields, and a challenging legal framework regarding new water rights appropriations. In 2013, the City Commission adopted an Integrated Water Resources Plan (Plan) to guide future water use and supply policies and practices. The Plan calls for water conservation to reduce the future water supply and demand gap by 50% over the next 40 years. Outdoor watering of lawns and landscapes represents fifty percent of annual residential water use in Bozeman. A recent analysis of single-household water use based on year-built indicates that homes built over the last decade are applying over twice the amount of water to landscapes as compared to older homes, despite being located on smaller lots with less landscaping. This is likely due in large part to the installation of inefficient irrigation systems and high water use turfgrass in new construction. 

On February 15, 2022, the City Commission held a work session to consider water efficient landscape and irrigation performance and design standards (standards) for new development to reduce Bozeman’s water supply and demand gap. During the work session, City staff presented three ‘tiers’ of standards. The tiers demonstrated various levels of outdoor water use reduction that could be achieved through the implementation of landscape and irrigation standards. During the work session, the City Commission directed staff to develop standards that align with Tier 3, which represented an extensive set of standards resulting in the greatest water savings. The implementation of Tier 3 standards is estimated to save 421 million gallons of water by the year 2040—enough water to support over 5,000 new single-households or 10,000 multi-household units. The standards were developed through a multi-pronged approach that included reviewing other municipal water efficiency standards, researching current best practices associated with landscape and irrigation systems, and soliciting feedback from the local landscape and irrigation design community through various engagement opportunities.  

The Landscape and Irrigation Performance and Design Standards Manual (“Manual”) was developed to establish water efficient landscape and irrigation performance and design standards required pursuant to Bozeman Municipal Code (BMC) 38.550.060. These project types are not required to go through the full plan review process and are instead afforded a simpler self-certification process. The full detailed requirements for these project types are in Section 2 of the Manual, beginning on page 9. The self-certification form for these project types can be found in Appendix E on page 38 of the Manual. To simplify the submittal requirements for these project types, no landscape or irrigation plan is required to receive a building permit.

The Landscape and Irrigation Performance and Design Standards Manual (“Manual”) was developed to establish water efficient landscape and irrigation performance and design standards required pursuant to Bozeman Municipal Code (BMC) 38.550.040. The full detailed requirements are in Section 3 of the manual, beginning on page 12. Landscaping requirements can be found in Section 3.2, starting on page 13.  Irrigation requirements can be found in Section 3.3, starting on page 21. These projects will be required to submit full landscaping and irrigation plans as part of the development review process.  These submittals, combined with a required pre-installation meeting, are intended to ensure that new projects achieve compliance. The landscape design plan requirements are located in Section 3.2.2, which begins on page 18. The irrigation plan requirements can be found in Section 3.3.3, beginning on page 22. To learn more about what is required during the pre-installation meeting, see Section 3.1.3 on page 12.

To achieve compliance with the City of Bozeman Landscape and Irrigation Performance and Design Standards Manual follow the flowchart below for your project. 

The performance pathway to achieve landscape design compliance (outlined in the Manual) includes two resources to determine how much water a landscape will require: a plant list and a water budget calculator. The plant list includes many USDA hardiness zone 4 plants, that are suitable for Bozeman’s climate. The list contains plant information such as size, bloom color, sun requirements, and other information to aid in plant selection. 
The list also includes a plant factor for each plant, which represents the relative water demand of the plant when compared to a reference crop of alfalfa. For example, alfalfa has a plant factor of 1.0, whereas Kentucky bluegrass has a plant factor of 0.8, and Russian Sage has a plant factor of 0.1. The lower the plant factor, the less water the plant requires. Applicants seeking landscape design compliance through the performance pathway are required to use the plant list plant factors in addition to the water budget calculator.

Plant List

The water budget calculator is the key tool that must be used when following the performance pathway to achieve landscape design compliance. The total landscaped area occupied by each plant factor must be entered into the water budget calculator to determine the average number of gallons of supplemental irrigation required per square foot of landscaped area per growing season to maintain a healthy landscape. Projects subject to Section 2 of the Manual are afforded a water budget of 10 gallons per square foot of landscaped area per year; projects subject to Section 3 are afforded a water budget of 8 gallons per square foot of landscaped area per year. Full instructions on how to use the water budget calculator can be found in Appendix D on page 33 of the Manual. 

Water Budget Calculator

To achieve compliance with the City of Bozeman Landscape and Irrigation Performance and Design Standards Manual, applicants must demonstrate that the irrigation zone that will experience the most pressure loss due to fittings, distance, and/or elevation will be able to function within the pressure range specified by the manufacturer of the irrigation product. The Water Conservation Division has created a pressure loss calculator to simplify this process for project applicants and a guide to make it easy to use. 

 Guide to Pressure Loss Calculator

Pressure Loss Calculator