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Home My WebLink AboutPZ - Ada-County-ID-Jail-Impact-Fee-Study_5.24.24 (1) OF14 Jail Capital Improvement Plan and Development Impact Fee Study Submitted to: Ada County, Idaho May 24, 2024 Prepared by: TischlerBise FISCAL I ECONOMIC I PLANNING 999 W Main St Suite 100 Boise, ID 83702 800.424.4318 www.tischlerbise.com Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study [Page intentional blank] i TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study Impact Fee Study Ada County, Idaho ExecutiveSummary .......................................................................................................................................1 Idaho Development Impact Fee Enabling Legislation ...............................................................................2 Summary of Capital Improvement Plans and Development Impact Fees.................................................3 Methodologiesand Credits ...................................................................................................................3 FeeMethodologies................................................................................................................................4 CapitalImprovement Plan.....................................................................................................................5 Maximum Supportable Development Impact Fees by Type of Land Use.............................................6 CapitalImprovement Plan.............................................................................................................................7 CapitalImprovement Plan.....................................................................................................................9 Funding Sources for Capital Improvements........................................................................................10 Jail Development Impact Fee Analysis.........................................................................................................11 Cost Allocation for Jail Infrastructure......................................................................................................12 Jail Level of Service and Cost Analysis .....................................................................................................13 JailCapacity Analysis............................................................................................................................13 JailAncillary Facilities ..........................................................................................................................13 JailBeds................................................................................................................................................14 Share of the Development Impact Fee Study......................................................................................15 Jail Capital Improvements Needed to Serve Growth ..............................................................................16 JailAncillary Facilities ..........................................................................................................................16 JailBeds................................................................................................................................................17 Jail Development Impact Fee Credit Analysis..........................................................................................18 Jail Input Variables and Development Impact Fees.................................................................................18 Cash Flow Projections for Jail Maximum Supportable Impact Fee .........................................................19 Proportionate Share Analysis ......................................................................................................................20 Implementation and Administration...........................................................................................................21 Appendix A. Land Use Definitions ...............................................................................................................23 ResidentialDevelopment.........................................................................................................................23 Nonresidential Development Categories ................................................................................................24 Appendix B. Demographic Assumptions .....................................................................................................25 Population and Housing Characteristics..................................................................................................25 Base Year Population and Housing Units.................................................................................................26 Population and Housing Unit Projections................................................................................................29 Current Employment and Nonresidential Floor Area..............................................................................31 Employment and Nonresidential Floor Area Projections........................................................................32 VehicleTrip Generation...........................................................................................................................36 Residential Vehicle Trips by Housing Type..........................................................................................36 Residential Vehicle Trips Adjustment Factors.........................................................................................37 ii TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study Nonresidential Vehicle Trips....................................................................................................................38 VehicleTrip Projections...........................................................................................................................39 TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study EXECUTIVE SUMMARY Ada County, Idaho, retained TischlerBise, Inc. to calculate the impact fees to be imposed on new development to meet the new demands generated for public facilities in the County. It is the intent of Ada County to evaluate and establish impact fees for jail facilities.This report presents the methodologies and calculations used to generate current levels of service and maximum supportable impact fees. It is intended to serve as supporting documentation for the evaluation and establishment of impact fees in Ada County. The purpose of this study is to demonstrate the County's compliance with Idaho Statutes as authorized by the Idaho Legislature. Consistent with the statutory authorization for development impact fees (Idaho Code 67-8202(1-4)), it is the intent of Ada County to: 1. Collect impact fees to ensure that adequate public facilities are available to serve new growth and development; 2. Promote orderly growth and development by establishing uniform standards by which local governments may require that those who benefit from new growth and development pay a proportionate share of the cost of new public facilities needed to serve new growth and development; 3. Establish minimum standards for the adoption of development impact fee ordinances by government entities; 4. Ensure that those who benefit from new growth and development are required to pay no more than their proportionate share of the cost of public facilities needed to serve new growth and development and to prevent duplicate and ad hoc development requirements; Impact fees are one-time payments used to construct system improvements needed to accommodate new development. An impact fee represents new growth's fair share of capital facility needs. By law, impact fees can only be used for capital improvements, not operating or maintenance costs. Impact fees are subject to legal standards, which require fulfillment of three key elements: need, benefit and proportionality. • First, to justify a fee for public facilities, it must be demonstrated that new development will create a need for capital improvements. • Second, new development must derive a benefit from the payment of the fees (i.e., in the form of public facilities constructed within a reasonable timeframe). • Third, the fee paid by a particular type of development should not exceed its proportional share of the capital cost for system improvements. 1 TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study TischlerBise evaluated possible methodologies and documented appropriate demand indicators by type of development for the levels of service and fees. Local demographic data and improvement costs were used to identify specific capital costs attributable to growth. This report includes summary tables indicating the specific factors, referred to as level of service standards, used to derive the impact fees. The geographic area for the jail impact fees is countywide. These facilities provide a countywide benefit and are services not provided by the cities within Ada County. IDAHO DEVELOPMENT IMPACT FEE ENABLING LEGISLATION The Enabling Legislation governs how development fees are calculated for municipalities in Idaho. All requirements of the Idaho Development Impact Fee Act(hereafter referred to as the Idaho Act) have been met in the supporting documentation prepared by TischlerBise. There are four requirements of the Idaho Act that are not common in the development impact fee enabling legislation of other states. This overview offers further clarification of these unique requirements. First, as specified in 67-8204(2) of the Idaho Act, "development impact fees shall be calculated on the basis of levels of service for public facilities . . . applicable to existing development as well as new growth and development." Second, Idaho requires a Capital Improvements Plan (CIP) [see 67-8208]. The CIP requirements are summarized in this report, with detailed documentation provided in the discussion on infrastructure. Third,the Idaho Act also requires documentation of any existing deficiencies in the types of infrastructure to be funded by development impact fees [see 67-8208(1)(a)]. The intent of this requirement is to prevent charging new development to cure existing deficiencies. In the context of development impact fees for Ada County, the term "deficiencies" means a shortage or inadequacy of current system improvements when measured against the levels of service to be applied to new development. It does not mean a shortage or inadequacy when measured against some "hoped for" level of service. TischlerBise used the current infrastructure cost per service unit (i.e., existing standards), or future levels of service where appropriate, multiplied by the projected increase in service units over an appropriate planning timeframe,to yield the cost of growth-related system improvements.The relationship between these three variables can be reduced to a mathematical formula, expressed as A x B = C. In section 67- 8204(16), the Idaho Act simply reorganizes this formula, stating the cost per service unit (i.e., development impact fee) may not exceed the cost of growth-related system improvements divided by the number of projected service units attributable to new development (i.e., A = C - B). By using existing infrastructure standards to determine the need for growth-related capital improvements, Ada County ensures the same level-of-service standards are applicable to existing and new development. Using existing infrastructure standards also means there are no existing deficiencies in the current system that must be corrected from non-development impact fee funding. 2 TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study Fourth, Idaho requires a proportionate share determination [see 67-8207]. Basically, local government must consider various types of applicable credits and/or other revenues that may reduce the capital costs attributable to new development.The development impact fee methodologies and the cash flow analysis have addressed the need for credits to avoid potential double payment for growth-related infrastructure. SUMMARY OF CAPITAL IMPROVEMENT PLANS AND DEVELOPMENT IMPACT FEES METHODOLOGIES AND CREDITS Development impact fees can be calculated by any one of several legitimate methods. The choice of a particular method depends primarily on the service characteristics and planning requirements for each facility type. Each method has advantages and disadvantages in a particular situation, and to some extent can be interchangeable, because each allocates facility costs in proportion to the needs created by development. Reduced to its simplest terms, the process of calculating development impact fees involves two main steps: (1) determining the cost of development-related capital improvements and (2) allocating those costs equitably to various types of development. In practice, though, the calculation of impact fees can become quite complicated because of the many variables involved in defining the relationship between development and the need for facilities. The following paragraphs discuss three basic methods for calculating development impact fees, and how each method can be applied. Cost Recovery or Buy-In Fee Calculation. The rationale for the cost recovery approach is that new development is paying for its share of the useful life and remaining capacity of facilities already built or land already purchased from which new growth will benefit. This methodology is often used for systems that were oversized such as sewer and water facilities. Incremental Expansion Fee Calculation.The incremental expansion method documents the current level of service (LOS)for each type of public facility in both quantitative and qualitative measures, based on an existing service standard (such as park land acres per 1,000 residents). This approach ensures that there are no existing infrastructure deficiencies or surplus capacity in infrastructure. New development is only paying its proportionate share for growth-related infrastructure. An incremental expansion cost method is best suited for public facilities that will be expanded in regular increments, with LOS standards based on current conditions in the community. Plan-Based Fee Calculation. The plan-based method allocates costs for a specified set of improvements to a specified amount of development. Facility plans identify needed improvements, and land use plans identify development. In this method, the total cost of relevant facilities is divided by total demand to calculate a cost per unit of demand. Then, the cost per unit of demand is multiplied by the amount of demand per unit of development (e.g., housing units or square feet of building area) in each category to arrive at a cost per specific unit of development (e.g., single family detached unit). 3 TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study Credits. Regardless of the methodology, a consideration of "credits" is integral to the development of a legally valid impact fee methodology. There are two types of "credits," each with specific and distinct characteristics, but both of which should be addressed in the calculation of development impact fees.The first is a credit due to possible double payment situations.This could occur when contributions are made by the property owner toward the capital costs of the public facility covered by the impact fee. This type of credit is integrated into the impact fee calculation.The second is a credit toward the payment of a fee for dedication of public sites or improvements provided by the developer and for which the facility fee is imposed. This type of credit is addressed in the administration and implementation of a facility fee program. FEE METHODOLOGIES Of the fee methodologies discussed above, the incremental expansion method and the cost recovery method are used to calculate jail impact fees for Ada County.Where capacity is sufficient to serve current demand the incremental expansion method documents the current Level of Service (LOS) for each type of public facility. While the cost of the impact fee study is captured through the cost recovery method. Additionally,Ada County anticipates working with the cities to collect the jail impact fee countywide.The following table summarizes the method(s) used to derive the jail impact fee in Ada County. Figure 1. Summary of Impact Fee Methodologies Fee Category Service Area Cost Incremental Plan-Based Cost Recovery Expansion Allocation Jail Countywide Impact Fee Study Jail Facilities Person&Vehicle Trips 4 TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study CAPITAL IMPROVEMENT PLAN The jail development impact fee is based on the existing level of service provided for jail facilities. The development impact fee is calculated for residential and nonresidential development.To serve projected growth at current levels of service,the jail will need to provide 16,555 square feet of new ancillary facility space and 178 new jail beds over the next 10 years. Listed in Figure 2 are the capital improvement plans for facility expansion for the next 10 years. The planned expansions are consistent with growth-related needs to continue providing the current level of service. Important to note is that of the total $16 million ancillary facility costs, only $12.5 million will be captured by the impact fees. The CIP also includes non- growth-related projects which will be funded with non-impact fee revenue. Figure 2.Jail Capital Improvement Plan 10-Year Jail 10-Year General Fund Capital Improvement Plan Square Feet Total • .. Other Sources Pod E Expansion (294 beds) 39,984 $32,843,108 $19,936,000 $12,907,108 Pod E Locker Rooms 3,000 $2,464,219 $2,464,219 $0 Warehouse 10,562 $6,967,817 $6,967,817 $0 Second Secured Entrance 6,719 $6,352,666 $6,352,666 $0 New Booking Room 1,000 $270,229 $270,229 $0 Kitchen Remodel 4,609 $4,992,463 $0 $4,992,463 Camera Installation - $1,322,421 $0 $1,322,421 Restroom& Locker Room Remodel $138,831 $0 $138,831 Jail Management System Upgrade - $4,000,000 $0 $4,000,000 Total 65,874 $59,351,755 $35,990,932 $23,360,823 Growth-Related Pod Expansion $19,936,000 Pod Expansion Revenue $19,936,000 Growth-Related Pod Expansion Funding Gap $0 Growth-Related Anc. Facility Expansion $16,054,932 Anc. Facility Expansion Revenue $12,499,025 Growth-Related Anc.Facility Funding Gap $3,555,907 5 TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study MAXIMUM SUPPORTABLE DEVELOPMENT IMPACT FEES BY TYPE OF LAND USE Figure 3 provides a schedule of the maximum supportable development impact fees by type of land use for Ada County. The fees represent the highest supportable amount for each type of applicable land use and represents new growth's fair share of the cost for capital facilities. The County may adopt fees that are less than the amounts shown. However,a reduction in impact fee revenue will necessitate an increase in other revenues, a decrease in planned capital expenditures, and/or a decrease in levels of service. The fees for residential development are to be assessed per housing unit based on type. For nonresidential development, the fees are assessed per square foot of floor area (for illustrative purposes the nonresidential fee is listed per 1,000 square feet of development). Nonresidential development categories are consistent with the terminology and definitions contained in the reference book,Trip Generation 111n Edition, published by the Institute of Transportation Engineers. These definitions are provided in the Appendix A. Land Use Definitions. Importantly, the Ada County Jail provides a countywide service and benefit. Thus, the impact fee study has calculated the maximum supportable fee based on a countywide level of service. In this case, Figure 3 lists maximum amounts for all development within Ada County. Figure 3. Summary of Maximum Supportable Development Impact Fees -Countywide DevelopmentJail Maximum Supportable Residential (per housing unit) Single Family Multifamily Nonresidential(per 1,000 square feet) Retail ' Office Industrial Institutional 6 TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study IMPROVEMENTCAPITAL The following section provides a summary of the Capital Improvement Plan depicting growth-related capital demands and costs on which the fees are based. First, Figure 4 and Figure 5 lists the projected growth over the next ten years in Ada County.Overall,there is an estimated 23 percent increase in residential development (125,397 new residents and 50,296 new housing units) and an 18 percent increase in nonresidential development (43,283 new jobs and 16.9 million square feet of development). Further details on the development projections are provided in Appendix B. Demographic Assumptions. 7 TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study Figure 4.Ten-Year Projected Residential Growth Base Year Total 2026 2027i i29 2030 2031i Population 1 544,5901 568,015 591,946 602,628 613,310 623,991 634,673 645,355 653,566 661,776 669,987 125,397 Percent Increase 4.3% 4.2% 1.8% 1.8% 1.7% 1.7% 1.7% 1.3% 1.3% 1.2% 23.0% Housing Units Si ngl a Fa mi I y 182,342 190,171 198,180 201,750 205,321 208,891 212,462 216,033 218,774 221,515 224,256 41,914 Multifamily 37,833 39,417 41,005 41,716 42,426 43,137 43,847 44,558 45,110 45,662 46,215 8,382 Total Housing Units 220,175 229,588 239,185 243,466 247,747 252,028 256,309 260,591 263,884 267,177 270,471 50,296 Source:COMPASS(Community Planning Association of Southwest Idaho)Traffic Analysis Zone Model;City& Fire District Impact Fee Studies; TischlerBise analysis Figure 5.Ten-Year Projected Nonresidential Growth Base Year Total Ada County 2023 2024 2025 2026 2027 2028 2029 2030 Jobs[l] Retail 43,787 44,612 45,437 46,262 47,086 47,910 48,734 49,557 50,367 51,177 51,986 8,199 Office 130,780 133,132 135,483 137,835 140,186 142,538 144,889 147,241 149,556 151,872 154,187 23,407 Industrial 35,745 36,388 37,030 37,673 38,315 38,958 39,600 40,242 40,875 41,507 42,139 6,394 Institutional 29,356 29,884 30,413 30,943 31,472 32,003 32,533 33,064 33,588 34,113 34,639 5,283 Total 1 239,6681 244,016 248,364 252,712 257,060 261,408 265,756 270,104 274,386 278,669 282,951 43,283 Nonresidential Floor Area(1,000 sq.ft.)[2] Retail 41,938 42,327 42,715 43,104 43,492 43,880 44,268 44,656 45,037 45,419 45,800 3,862 Office 21,670 22,392 23,114 23,836 24,558 25,280 26,002 26,724 27,434 28,145 28,856 7,186 Industrial 41,668 42,078 42,487 42,896 43,305 43,715 44,124 44,533 44,936 45,339 45,741 4,073 Institutional 25,911 26,096 26,281 26,467 26,652 26,838 27,023 27,209 27,392 27,576 27,760 1,849 Total 131,1881 132,893 134,598 136,302 138,007 139,712 141,417 143,121 144,800 146,479 148,1571 16,970 [1] COMPASS(Community Planning Association of Southwest Idaho)Traffic Analysis Zone Model;Communities in Motion 2050;TischlerBise analysis [2]Source: Institute of Transportation Engineers, Trip Generation, 2021 8 TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study The Idaho Development Impact Fee Act requires Capital Improvement Plans to be updated regularly, at least once every five years (Idaho Code 67-8208(2)).This report projects revenue and fees based on a 10- year forecast in an effort to provide the public and elected officials with illustrative guidance of probable growth demands based on current trends however, per Idaho Code, it is expected that an update to all Capital Improvement Plans included in this study will occur within five years. FUNDING SOURCES FOR CURRENT DEFICIENCIES The majority of the CIP relates to the expansion of the Ada County Jail. A number of specific upgrades, replacements, and expansions to existing Jail facilities have also been proposed for fiscal year 2025 and beyond. In addition, it is estimated that$2,500,000 will be required for maintenance and repair of existing facilities over the next five years. Because replacement and addressing existing deficiencies are not eligible to be funded with impact fees,these costs will need to be funded by other sources,such as property taxes, in accordance with Idaho Code 67-8207(iv)(2)(h). The Board of Ada County Commissioners retain discretion and authority to fund deficiencies through the county's annual CIP budget process,accumulate savings annually in a construction fund,budget annually for one-time projects using unspent fund balance, or through the deferred maintenance budget annually appropriated to the Operations Department for these sorts of expenses. CAPITAL IMPROVEMENT PLAN The jail development impact fee is based on the existing level of service provided for jail facilities. The development impact fee is calculated for residential and nonresidential development. Based on the 10- year growth projections,the following infrastructure is projected over the next ten years: • 16,555 square feet of new ancillary facility • 178 new jail beds • $32,435,000 growth-related costs to Ada County The projected demand is consistent with the Ada County Jail expansion plans. Currently,the department is exploring options for several expansions within the jail including a warehouse expansion and locker rooms for future Pod E. These projections are consistent with the Jail's Capital Improvement Plan shown in Figure 77. Important to note is that of the total$16 million ancillary facility costs,only$12.5 million will be captured by the impact fees. Also, there are four capital projects which are addressing non-growth- related project,thus not impact fee eligible. 9 TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study Figure 7.Jail Capital Improvement Plan 10-Year Jail 10-Year I General Fund ImprovementCapital .. Other Sources Pod E Expansion (294 beds) 39,984 $32,843,108 $19,936,000 $12,907,108 Pod E Locker Rooms 3,000 $2,464,219 $2,464,219 $0 Warehouse 10,562 $6,967,817 $6,967,817 $0 Second Secured Entrance 6,719 $6,352,666 $6,352,666 $0 New Booking Room 1,000 $270,229 $270,229 $0 Kitchen Remodel 4,609 $4,992,463 $0 $4,992,463 Camera Installation - $1,322,421 $0 $1,322,421 Restroom& Locker Room Remodel $138,831 $0 $138,831 Jail Management System Upgrade - $4,000,000 $0 $4,000,000 Total 65,874 $59,351,755 $35,990,932 $23,360,823 Growth-Related Pod Expansion $19,936,000 Pod Expansion Revenue $19,936,000 Growth-Related Pod Expansion Funding Gap $0 Growth-Related Anc. Facility Expansion $16,054,932 Anc. Facility Expansion Revenue $12,499,025 Growth-Related Anc.Facility Funding Gap $3,555,907 FUNDING SOURCES FOR CAPITAL IMPROVEMENTS In determining the proportionate share of capital costs attributable to new development, the Idaho Development Fee Act states that local governments must consider historical, available, and alternative sources of funding for system improvements (Idaho Code 67-8207(2)). Currently, there are no dedicated revenues being collected by the County to fund growth-related projects for the infrastructure included in this study. Furthermore, the maximum supportable impact fees are constructed to offset the growth-related capital costs to the County for jail facilities. Evidence is given in the specific chapters of this report that the projected capital costs from new development will be offset by the development impact fees collection as long as the program is collected in the entire service area. Thus, no credits are needed in the impact fee calculation to offset double collection for growth-related capital costs. 10 TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study DEVELOPMENTJAIL ANALYSIS The Jail Development Impact Fee is based on the cost per service unit method specified in Idaho Code 67- 8204(16), also referred to as the incremental expansion method elsewhere in this report. The jail components included in the impact fee analysis are: • Jail ancillary facilities • Jail beds • Share of the development impact fee study The residential portion of the fee is derived from the product of persons per housing unit by housing type multiplied by the net capital cost per person. To calculate nonresidential development impact fees, nonresidential vehicle trips are used as the demand indicator. Trip generation rates are highest for commercial developments, such as shopping centers, and lowest for industrial development. Office and institutional land uses trip rates fall between the other two categories. This ranking of trip rates is consistent with the relative demand for jail facilities from nonresidential development and thus are the best demand indicators. Other possible nonresidential demand indicators, such as employment or floor area, do not accurately reflect the demand for service. If employees per thousand square feet were used as the demand indicator, Jail Development Impact Fees would be too high for office and institutional development. If floor area were used as the demand indicator, the development impact fees would be too high for industrial development. (See the Appendix for further discussion on trip rates and calculations.) Specified in Idaho Code 67-8207(2), local governments must consider historical, available, and alternative sources of funding for system improvements. Currently,there are no dedicated revenues being collected by the County to fund growth-related projects for jail facilities. Furthermore, the maximum supportable impact fees are constructed to offset all growth-related capital costs for jail facilities. Evidence is given in this chapter that the projected capital costs from new development will be entirely offset by the development impact fees. Thus, no general tax dollars are assumed to be used to fund growth-related capital costs, requiring no further revenue credits. 11 TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study COST ALLOCATION FOR JAIL INFRASTRUCTURE Both residential and nonresidential development increases the demand for jail services and facilities. To calculate the proportional share between residential and nonresidential demand calls for service data from the Ada County Sheriff is analyzed.This call report represents the need for law enforcement services throughout Ada County including calls to which City police departments responded. Shown at the top of Figure 88, 32 percent of calls are to residential locations, 12 percent to nonresidential locations, and 56 percent are classified as traffic calls. Base year vehicle trips are used to assign traffic calls to residential and nonresidential land uses. This results in 41,125 additional residential calls (1,138,874 residential vehicle trips/ 2,087,130 total vehicle trips x 75,367 traffic calls for service) and 34,242 additional nonresidential calls (948,256 nonresidential vehicle trips/2,087,130 total vehicle trips x 75,367 traffic calls for service). After this adjustment, 63 percent of calls are attributed to residential development and 37 percent are attributed to nonresidential development.These percentages are used to attribute facilities to respective demand units. Figure 8. Countywide Law Enforcement Calls for Service M- - - - - Residential 42,779 32% Nonresidential 15,958 12% Traffic 75,367 56% Total 134,105 100% Vehicle Land Use Trips %of Total Residential 1,138,874 55% Nonresidential 948,256 45% Total 2,087,130 100% Adj.Calls Land Use for Service %of Total Residential 83,905 Nonresidential 50,200 Total 134,105 100% Source:Ada County Sheriff's Office 12 TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study JAIL LEVEL OF SERVICE AND COST ANALYSIS The following section details the level of service calculations and capital cost per person for each infrastructure category. JAIL CAPACITY ANALYSIS Shown in Figure 99 is an analysis of the Ada County share of square footage and jail beds.The Ada County Jail houses inmates awaiting transfer to the Idaho State Prison and pretrial hearings. Of the 200 currently held for these reasons, 10 of them are from outside of Ada County.These 10 out-of-county prisoners are then divided by the operational capacity of the jail to get the out of county utilization of 1 percent (10 out-of-county inmates/949 operational capacity= 1 percent out-of-county utilization). Figure 9.Ada County Jail Capacity Analysis Ada County Jail Jail Operational Capacity 949 County Inmates Awaiting Transfer/Hearing 200 Portion of Awaiting Inmates Out-of-County(5%) 10 Portion of Jail Capacity Out-of-County 1% JAIL ANCILLARY FACILITIES Listed in Figure 1010, there is a total of 87,956 square feet of ancillary facilities at the county jail, 87,710 square feet being attributed to Ada County demand (99 percent). The proportionate share between residential and nonresidential demand of the facilities is found by applying the calls for service data percentages. As a result, 54,877 square feet are attributed to residential demand and 32,833 square feet are attributed to nonresidential demand.The current level of service is found by comparing the attributed square footage to the base year population and nonresidential vehicles trips. As a result, there is 100.8 square feet per 1,000 residents and 34.6 square feet per 1,000 vehicles trips. The average cost per square foot is combined with the current levels of service to find the capital cost per demand unit.This results in a cost of$76 per person and $26 per vehicle trip(100.8 square feet per 1,000 persons x$755 per square foot= $76 per person, rounded). 13 TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study Figure 10.Jail Facility Level of Service&Cost Analysis Total Ada County Ada County Facility Square Feet � Portion 99% � Replacement Cost Medical Unit 24,607 24,361 $20,010,220 Work Release 12,980 12,980 $5,612,125 Juvenile Detention 49,012 49,012 $40,258,763 ASCO Vehicle Maintenance 1,357 1,357 $366,634 Total 87,956 87,710 $66,247,743 Level-of-Service Standards Residential Nonres Proportional Share 63% 37% Share of Square Feet 54,877 32,833 2023 Population/Nonres.Vehicle Trips 544,590 948,256 ��Square Feet per � Cost Analysis Residential Nonres Square Feet per 1,000 Persons/Vehicle Trips 100.8 34.6 Average Cost per Square Foot $755 $755 Capital Cost per Person/Vehicle Trip 1 $761 $26 Source:Ada County Sheriff's Office JAIL BEDS Listed in Figure 61, the jail operational capacity is 949 occupied beds, 940 of which are utilized by Ada County(99 percent).The proportionate share between residential and nonresidential demand of the beds is found by applying the calls for service data percentages. As a result, 588 beds are attributed to residential demand and 352 beds are attributed to nonresidential demand.The current level of service is found by comparing the attributed beds to the base year population and nonresidential vehicles trips. As a result, there are 1.08 beds per 1,000 residents and 0.37 beds per 1,000 vehicles trips. The average cost per bed is combined with the current levels of service to find the capital cost per demand unit. This results in a cost of $121 per person and $41 per vehicle trip (1.08 beds per 1,000 persons x $112,000 per bed = $121 per person, rounded). 14 TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study Figure 61.Jail Bed Level of Service&Cost Analysis Operational CapacityFacility Ja i I 9491 100%1 940 $105,280,000 Total 949 940 $105,280,000 Level-of-Service Standards Residential Nonres Proportional Share 63% 37% Share of Beds 588 352 2023 Population/Nonres.Vehicle Trips 544,590 948,256 Beds per 000 0: Cost Analysis Residential Nonres Beds per 1,000 Persons/Vehicle Trips 1 1.081 0.37 Average Cost per Bed [2] 1 $112,0001 $112,000 Capital Cost per Person/Vehicle Trip 1 $1211 $41 [1]Jail population model forcasts 100%utilization by the beginning of 2024 [2] Based on Pod E expansion of 294 beds at$32,843,108 including contingencies and FFE SHARE OF THE DEVELOPMENT IMPACT FEE STUDY Under the Idaho enabling legislation, Ada County is able to recover the cost of the study through the collection of future fees. The total cost of the study has been evenly attributed to the four infrastructure categories, resulting in the Jail category share being $16,370. An impact fee study must be completed every five years, so the attributed cost is compared to the five-year projected increase. As a result, the cost per person is$0.13 and the cost per vehicle trip is $0.11. Figure 72.Jail Share of the Development Impact Fee Study Share of Residential Nonresidential Study Cost Share Share $16,370 63% 1 37% Residential Five-Year Capital Cost 11 Growth Co! Population ncrease per Person $10,242 79,401 Nonresidential Five-Year Capital Cost Growth Cost Vehicle Tr ip Increase per Vehicle Trip $6,128 56,847 15 TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study JAIL CAPITAL IMPROVEMENTS NEEDED TO SERVE GROWTH Needs due to future growth were calculated using the levels of service and cost factors for the infrastructure components. Growth-related needs are a projection of the amount of infrastructure and estimated costs over the next ten years needed to maintain levels of service. JAIL ANCILLARY FACILITIES The current levels of service are combined with the population and vehicle trip projections to illustrate the need for new jail ancillary facilities. Shown in Figure 83, over the next ten years, there is a need for 16,555 square feet.The average cost per square foot is multiplied by the need to find the projected capital need from growth ($12,449,025). Figure 83. Projected Demand for Jail Ancillary Facilities Infrastructure I Level of Service Cost/Unit And Ilary Jai I Residential 100.8 per 1,000 persons Square Feet $755 Facilities Nonresidential 34.6 per 1,000veh.trips Growth-Related Need for Ancillary Jail Facilities Year Population Nonres. Residential Nonresidential Total I- Vehicle Trips Square Feet Square FE Square Feet Base 2023 544,590 948,256 54,894 32,809 87,703 Yea r 1 2024 568,015 959,629 57,255 33,203 90,458 Year 2 2025 591,946 971,000 59,668 33,596 93,264 Year 3 2026 602,628 982,369 60,744 33,989 94,733 Year 4 2027 613,310 993,737 61,821 34,383 96,204 Year 5 2028 623,991 1,005,103 62,898 34,776 97,674 Year 6 2029 634,673 1,016,467 63,975 35,169 99,144 Year 7 2030 645,355 1,027,830 65,051 35,562 100,613 Year 8 2031 653,566 1,039,020 65,879 35,950 101,829 Year 9 2032 661,776 1,050,206 66,707 36,337 103,044 Year 10 2033 669,987 1,061,389 67,534 36,724 104,258 Ten-Year Increase 125,397 113,134 12,640 3,915 16,555 Projected Expenditure $9,543,200 $2,955,825 $12,499,025 Growth-Related Expenditures for Ancillary Jail Facilities $12,499,025 16 TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study JAIL BEDS The current levels of service are combined with the population and vehicle trip projections to illustrate the need for new jail beds. Shown in Figure 94, over the next ten years,there is a need for 178 beds.The average cost per unit is multiplied by the need to find the projected capital need from growth ($19,936,000). Figure 94. Projected Demand for Jail Beds Infrastructure I Level of Service Cost/Unit Jail Facilities Residential 1.08 Beds per 1,000 persons Nonres i denti a 1 0.37 per 1,000 veh.trips $112,000 Growth-Related Need for Jail Facilities Year Population Nonres. Residential Nonresidential Total Beds Beds Beds Base 2023 544,590 948,256 588 351 939 Year 1 2024 568,015 959,629 613 355 968 Year 2 2025 591,946 971,000 639 359 998 Year 3 2026 602,628 982,369 651 363 1,014 Year 4 2027 613,310 993,737 662 368 1,030 Year 5 2028 623,991 1,005,103 674 372 1,046 Year 6 2029 634,673 1,016,467 685 376 1,061 Year 7 2030 645,355 1,027,830 697 380 1,077 Year 8 2031 653,566 1,039,020 706 384 1,090 Year 9 2032 661,776 1,050,206 715 389 1,104 Year 10 2033 669,987 1,061,389 724 393 1,117 Ten-Year Increase 125,397 113,134 136 42 178 Projected Expenditure $15,232,000 $4,704,000 $19,936,000 Growth-Related Expenditures for Jail Facilities $19,936,000 17 TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study JAIL DEVELOPMENT IMPACT FEE CREDIT ANALYSIS Currently,there are no dedicated revenues being collected by the County to fund growth-related projects for jail facilities. Furthermore, the maximum supportable impact fees are constructed to offset growth- related capital costs for facilities. Evidence is given in this chapter that the projected capital costs from new development will be entirely offset by the development impact fees. As a result, no revenue credit is necessary in the impact fee calculation. JAIL INPUT VARIABLES AND DEVELOPMENT IMPACT FEES Figure 105 provides a summary of the input variables (described in the chapter sections above) used to calculate the net cost per person and vehicle trip. The residential Jail Development Impact Fees are the product of persons per housing unit by type of dwelling unit multiplied by the total net capital cost per person.The nonresidential fees are the product of trips per 1,000 square feet multiplied by the net capital cost per nonresidential vehicle trip. The fees represent the highest supportable amount for each type of applicable land use and represents new growth's fair share of the cost for capital facilities. The County may adopt fees that are less than the amounts shown. However, a reduction in impact fee revenue will necessitate an increase in other revenues, a decrease in planned capital expenditures, and/or a decrease in levels of service. Figure 105.Jail Input Variables and Maximum Supportable Impact Fees ComponentFee Cost Cost , Jai I Beds $121.00 $41.00 Jail Ancillary Facilities $76.00 $26.00 Impact Fee Study $0.13 $0.11 Gross Total $197.13 $67.11 Net Total $197.13 $67.11 Residential SupportablePersons per Maximum Housing Type H Residential(per housing unit) Single Family 2.62 Multifamily 1.81 AMi Nonresidential DevelopmentVehicle Trips Maximum ... Nonresidential(per 1,000 square feet) Reta i 1 14.06 . Off ce 5.42 Industrial 2.44 Institutional 5.39 18 TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study CASH FLOW PROJECTIONS FOR JAIL MAXIMUM SUPPORTABLE IMPACT FEE This section summarizes the potential cash flow to Ada County if the Jail Development Impact Fee is implemented at the maximum supportable amounts. The cash flow projections are based on the assumptions detailed in this chapter and the development projections discussed in Appendix B. Shown at the bottom of Figure 16, the maximum supportable jail impact fee is estimated to generate $32.2 million in revenue while there is a growth-related cost of$32.4 million. Thus, the impact fees are able to offset all growth-related capital costs (note: the difference is the result of rounding in the calculations). The impact fee revenue is compared to the total Jail CIP to illustrate the non-impact fee funding needed to complete the plan. Importantly,the level of service has included demand from within the cities of Ada County.To ensure that the County captures the full potential revenue of the impact fees an intergovernmental agreement (IGA) is necessary for the Cities to collect the County impact fees on its behalf. Those revenues would be remitted to the County periodically. In the case there are no IGAs, the County will collect $3.1 million in the unincorporated areas (9.4 percent of the countywide growth-related capital costs). Figure 116. Projected Revenue for Jail Impact Fees Infrastructure Costs for Jail Facilities Total Cost Growth Cost Jail Beds $32,843,108 $19,936,000 Jail Ancillary Facilities $21,047,395 $12,499,025 Impact Fee Study $32,740 $32,740 Total Expenditures $53,923,243 $32,467,765 Projected Development Impact Fee Revenue OfficeSingle Family Multifamily Retail per uni per uni per KSF per KSF per KSF per KSF Year Housing Units Housing Units KSF KSF KSF KSF Base 2023 182,342 37,833 41,938 21,670 41,668 25,911 1 2024 190,171 39,417 42,327 22,392 42,078 26,096 2 2025 198,180 41,005 42,715 23,114 42,487 26,281 3 2026 201,750 41,716 43,104 23,836 42,896 26,467 4 2027 205,321 42,426 43,492 24,558 43,305 26,652 5 2028 208,891 43,137 43,880 25,280 43,715 26,838 6 2029 212,462 43,847 44,268 26,002 44,124 27,023 7 2030 216,033 44,558 44,656 26,724 44,533 27,209 8 2031 218,774 45,110 45,037 27,434 44,936 27,392 9 2032 221,515 45,662 45,419 28,145 45,339 27,576 10 2033 224,256 46,215 45,800 28,856 45,741 27,760 Ten-Year Increase 41,914 8,382 3,862 7,186 4,073 1,849 Projected Revenue $21,627,749 $2,992,275 $3,645,458 $2,615,726 $663,897 $667,499 Projected Revenue=> $32,213,000 Projected Expenditures=> $53,923,243 Non-Impact Fee Funding=> $21,710,243 19 TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study PROPORTIONATESHARE ANALYSIS Development impact fees for Ada County are based on reasonable and fair formulas or methods. The fees do not exceed a proportionate share of the costs incurred or to be incurred by the County in the provision of system improvements to serve new development.The County will fund non-growth-related improvements with non-development impact fee funds as it has in the past. Specified in the Idaho Development Impact Fee Act(Idaho Code 67-8207),several factors must be evaluated in the development impact fee study and are discussed below. 1) The development impact fees for Ada County are based on new growth's share of the costs of previously built projects along with planned public facilities as provided by Ada County. Projects are included in the County's capital improvements plan and will be included in annual capital budgets. 2) TischlerBise estimated development impact fee revenue based on the maximum supportable development impact fees for the one, countywide service area; results are shown in the cash flow analyses in this report. Development impact fee revenue will entirely fund growth-related improvements less funding from other sources (i.e.,federal and state grants). 3) TischlerBise has evaluated the extent to which new development may contribute to the cost of public facilities. 4) The relative extent to which properties will make future contributions to the cost of existing public facilities has also been evaluated in regards to existing debt. Outstanding debt for growth's portion of already constructed facilities will be paid from development impact fee revenue, therefore a future revenue credit is not necessary. 5) The County will evaluate the extent to which newly developed properties are entitled to a credit for system improvements that have been provided by property owners or developers.These"site- specific"credits will be available for system improvements identified in the annual capital budget and long-term Capital Improvements Plans. Administrative procedures for site-specific credits should be addressed in the development impact fee ordinance. 6) Extraordinary costs, if any, in servicing newly developed properties should be addressed through administrative procedures that allow independent studies to be submitted to the County. These procedures should be addressed in the development impact fee ordinance. One service area represented by Ada County is appropriate for the fees herein. 7) The time-price differential inherent in fair comparisons of amounts paid at different times has been addressed. All costs in the development impact fee calculations are given in current dollars with no assumed inflation rate overtime. Necessary cost adjustments can be made as part of the annual evaluation and update of development impact fees. 20 TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study IMPLEMENTATIONADMINISTRATION The Idaho Act requires jurisdictions to form a Development Impact Fee Advisory Committee. The committee must have at least five members with a minimum of two members active in the business of real estate, building, or development. The committee acts in an advisory capacity and is tasked to do the following: • Assist the governmental entity in adopting land use assumptions; • Review the capital improvements plan, and proposed amendments, and file written comments; • Monitor and evaluate implementation of the capital improvements plan; • File periodic reports, at least annually, with respect to the capital improvements plan and report to the governmental entity any perceived inequities in implementing the plan or imposing the development impact fees; and • Advise the governmental entity of the need to update or revise land use assumptions,the capital improvements plan, and development impact fees. Per the above, the County formed a Development Impact Fee Advisory Committee (DIFAC). TischlerBise and County Staff met with the DIFAC during the process and provided information on land use assumptions, level of service and cost assumptions, and draft development impact fee schedules. This report reflects comments and feedback received from the DIFAC. The County must develop and adopt a capital improvements plan (CIP)that includes those improvements for which fees were developed.The Idaho Act defines a capital improvement as an "improvement with a useful life of ten years or more, by new construction or other action, which increases the service capacity of a public facility." Requirements for the CIP are outlined in Idaho Code 67-8208. Certain procedural requirements must be followed for adoption of the CIP and the development impact fee ordinance. Requirements are described in detail in Idaho Code 67-8206. The County has a CIP that meets the above requirements. TischlerBise recommends that development impact fees be updated annually to reflect recent data. One approach is to adjust for inflation in construction costs by means of an index like the RSMeans or Engineering News Record (ENR).This index can be applied against the calculated development impact fee. If cost estimates change significantly the County should evaluate an adjustment to the CIP and development impact fees. Idaho's enabling legislation requires an annual development impact fees report that accounts for fees collected and spent during the preceding year (Idaho Code 67-8210). Development impact fees must be deposited in interest-bearing accounts earmarked for the associated capital facilities as outlined in capital improvements plans. Also, fees must be spent within eight years of when they are collected (on a first in, first out basis) unless the local governmental entity identifies in writing (a) a reasonable cause why the 21 TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study fees should be held longer than eight years;and (b)an anticipated date by which the fees will be expended but in no event greater than eleven years from the date they were collected. Credits must be provided for in accordance with Idaho Code Section 67-8209 regarding site-specific credits or developer reimbursements for system improvements that have been included in the development impact fee calculations. Project improvements normally required as part of the development approval process are not eligible for credits against development impact fees. Specific policies and procedures related to site-specific credits or developer reimbursements for system improvements should be addressed in the ordinance that establishes the County's fees. The general concept is that developers may be eligible for site-specific credits or reimbursements only if they provide system improvements that have been included in CIP and development impact fee calculations. If a developer constructs a system improvement that was included in the fee calculations, it is necessary to either reimburse the developer or provide a credit against the fees in the area that benefits from the system improvement.The latter option is more difficult to administer because it creates unique fees for specific geographic areas. Based on TischlerBise's experience, it is better for a reimbursement agreement to be established with the developer that constructs a system improvement. For example, if a developer elects to construct a system improvement, then a reimbursement agreement can be established to payback the developer from future development impact fee revenue. The reimbursement agreement should be based on the actual documented cost of the system improvement, if less than the amount shown in the CIP. However,the reimbursement should not exceed the CIP amount that has been used in the development impact fee calculations. 22 TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study APPENDixA. LAND USE DEFINITIONS RESIDENTIAL DEVELOPMENT As discussed below, residential development categories are based on data from the U.S. Census Bureau, American Community Survey. Ada County will collect impact fees from all new residential units. One-time impact fees are determined by the number of residential units. Single Family Units: 1. Single family detached is a one-unit structure detached from any other house, that is, with open space on all four sides. Such structures are considered detached even if they have an adjoining shed or garage.A one-family house that contains a business is considered detached as long as the building has open space on all four sides. 2. Single family attached (townhouse) is a one-unit structure that has one or more walls extending from ground to roof separating it from adjoining structures. In row houses (sometimes called townhouses), double houses, or houses attached to nonresidential structures, each house is a separate, attached structure if the dividing or common wall goes from ground to roof. 3. Mobile home includes both occupied and vacant mobile homes, to which no permanent rooms have been added. Mobile homes used only for business purposes or for extra sleeping space and mobile homes for sale on a dealer's lot,at the factory,or in storage are not counted in the housing inventory. Multifamily Units: 1. 2+ units (duplexes and apartments) are units in structures containing two or more housing units, further categorized as units in structures with "2, 3 or 4, 5 to 9, 10 to 19, 20 to 49, and 50 or more apartments." 2. Boat, RV, Van, etc. includes any living quarters occupied as a housing unit that does not fit the other categories(e.g.,houseboats, railroad cars,campers,and vans). Recreational vehicles, boats, vans, railroad cars, and the like are included only if they are occupied as a current place of residence. 23 TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study NONRESIDENTIAL DEVELOPMENT CATEGORIES Nonresidential development categories used throughout this study are based on land use classifications from the book Trip Generation (ITE, 2021). A summary description of each development category is provided below. Retail: Establishments primarily selling merchandise, eating/drinking places, and entertainment uses. By way of example, Retail includes shopping centers, supermarkets, pharmacies, restaurants, bars, nightclubs, automobile dealerships, and movie theaters. Office: Establishments providing management, administrative, professional, or business services. By way of example, Office includes business offices, office parks, and corporate headquarters. Industrial: Establishments primarily engaged in the production and transportation of goods. By way of example, Industrial includes manufacturing plants, trucking companies, warehousing facilities, utility substations, power generation facilities, and telecommunications buildings. Institutional: Public and quasi-public buildings providing educational, social assistance, or religious services. By way of example, Institutional includes schools, universities, churches, daycare facilities, hospitals, health care facilities, and government buildings. 24 TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study APPENDixB. DEMOGRAPHICASSUMPTIONS The data estimates and projections used in the study's calculations are detailed in this section. This chapter includes discussion and findings on: • Household/housing unit size • Current population and housing unit estimates • Residential projections • Current employment and nonresidential floor area estimates • Nonresidential projections • Functional population • Vehicle trip generation and projections POPULATION AND HOUSING CHARACTERISTICS Impact fees often use per capita standards and persons per housing unit or persons per household to derive proportionate share fee amounts. Housing types have varying household sizes and, consequently, a varying demand on County infrastructure and services. Thus, it is important to differentiate between housing types and size. When persons per housing unit(PPHU) is used in the development impact fee calculations, infrastructure standards are derived using year-round population. In contrast, when persons per household (PPHH) is used in the development impact fee calculations, the fee methodology assumes all housing units will be occupied, thus requiring seasonal or peak population to be used when deriving infrastructure standards. Thus,TischlerBise recommends that fees for residential development in Ada County be imposed according to persons per housing units. Based on housing characteristics, TischlerBise recommends using two housing unit categories for the Impact Fee study: (1) Single Family and (2) Multifamily. Each housing type has different characteristics which results in a different demand on County facilities and services. Figure 127 shows the US Census American Community Survey 2021 5-Year Estimates data for Ada County. Single family units have a housing unit size of 2.62 persons and multifamily units have a housing unit size of 1.81 persons. Additionally,there is a housing mix of 83 percent single family and 17 percent multifamily. The estimates in Figure 127 are for household size calculations. Base year population and housing units are estimated with another, more recent data source. TischlerBise 25 FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study Figure 127.Ada County Persons per Housing Unit Housing Housing Type Persons Units . . . . Single Family[1] 415,557 158,890 153,711 2.70 83% Multifamily[2] 59,917 33,161 31,014 1.93 17% Total 475,474 192,051 184,725 2.57 [1] Includes attached and detached single family homes and mobile homes [2] Includes all other types Source: U.S. Census Bureau, 2021 American Community Survey 5-Year Estimates The US Census American Community Survey 2021 5-Year Estimates data for incorporated Ada County is shown in Figure 138. Single family units have a housing unit size of 2.59 persons and multifamily units have a housing unit size of 1.80 persons. Additionally, there is a housing mix of 81 percent single family and 19 percent multifamily. Figure 138. Incorporated Ada County Persons per Housing Unit Housing HousingType Units . . . . Single Family[1] 363,946 140,266 135,502 2.69 81% Multifamily[2] 58,871 32,691 30,619 1.92 19% Total 422,817 172,957 166,121 2.55 [1] Includes attached and detached single family homes and mobile homes [2] Includes all other types Source: U.S. Census Bureau, 2021 American Community Survey 5-Year Estimates The US Census American Community Survey 2021 5-Year-Estimates data for unincorporated Ada County is shown in Figure 149. Single family units have a housing unit size of 2.77 persons and multifamily units have a housing unit size of 2.23 persons. Additionally, there is a housing mix of 98 percent single family and 2 percent multifamily. Figure 149. Unincorporated Ada County Persons per Housing Unit Housing Housing Type Units . . . . Single Family[1] 51,611 18,624 18,209 2.83 98% Multifamily[2] 1,046 470 395 2.65 2% Total 52,657 L 19,094 18,604 2.83 [1] Includes attached and detached single family homes and mobile homes [2] Includes all other types Source: U.S. Census Bureau, 2021 American Community Survey 5-Year Estimates BASE YEAR POPULATION AND HOUSING UNITS Available through the Community Planning Association of Southwest Idaho (COMPASS), the base year 2023 population in Ada County is estimated to be 554,590 residents shown in Figure20. PPHU factors for Tischl rBise 26 FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study Incorporated and Unincorporated Ada County were used to estimate base year housing units for the whole County. The housing unit mix for Ada County was then applied to the total giving an estimated 182,342 single family units and 37,833 multifamily units. Figure 20.Ada County Base Year Population and Housing Units Base Year Population [1] 544,590 Housing Units [2] Single Family 182,342 Multifamily 37,833 Total Housing Units 220,175 [1] COMPASS(Community Planning Association of Southwest Idaho)Traffic Analysis Zone Model [2] U.S.Census Bureau, 2021 American Community Survey 5-Year Estimates, TischlerBise analysis Available through COMPASS, the base year 2023 population in unincorporated Ada County is estimated to be 63,510 residents shown in Figure 151. PPHU factors for unincorporated Ada County were used to estimate base year housing units.The housing unit mix was then applied to the total giving an estimated 22,444 single family units and 566 multifamily units. Figure 151. Unincorporated Ada County Base Year Population and Housing Units Ada County Base Year Unini .. 2023 Population [1] 63,510 Housing Units[2] Single Family 22,444 Multifamily 566 Total Housing Units 23,011 [1]COMPASS(Community Planning Association of Southwest Idaho)Traffic Analysis Zone Model [2] U.S. Census Bureau, 2021 American Community Survey 5-Year Estimates, TischlerBise analysis The population estimate for unincorporated Ada County from COMPASS was subtracted from the population estimate for the whole of Ada County to find the estimated base year population for incorporated Ada County. Shown in Figure 162 the estimated population is 481,080. PPHU factors for incorporated Ada County were used to estimate base year housing units. The housing unit mix was then applied to the total giving an estimated 159,898 single family units and 37,266 multifamily units. T[schl raise 27 FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study Figure 162. Incorporated Ada County Base Year Population and Housing Units Ada County Base Year Incorporated i Population [1] 481, 880 Housing Units [21 Single Family 159,898 Multifamily 37,266 Total Housing Units 197,164 [1] COMPASS(Community Planning Association of Southwest Idaho)Traffic Analysis Zone Model [2] U.S. Census Bureau, 2021 American Community Survey 5-Year Estimates, TischlerBise analysis T[schlerBise 28 FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study POPULATION AND HOUSING UNIT PROJECTIONS The residential projections are based on a review of COMPASS published estimates, impact fee studies from cities and fire districts within Ada County, and PPHU factors. Impact fee studies comprising the main six cities within Ada County were used to affirm growth trends for whole county projections. From the 2023 base year housing unit totals, Ada County is projected to increase by 50,296 housing units over the next ten years. Additionally,there is a projected increase of 125,397 residents over the next ten years, a 23 percent increase. Figure 173.Ada County Residential Development Projections Base Year Total Population 1 544,5901 568,015 591,946 602,628 613,310 623,991 634,673 645,355 653,566 661,776 669,987 125,397 Percent Increase 4.3% 4.2% 1.8% 1.8% 1.7% 1.7% 1.7% 1.3% 1.3% 1.2% 23.0% Housing Units Single Family 182,342 190,171 198,180 201,750 205,321 208,891 212,462 216,033 218,774 221,515 224,256 41,914 Multifamily 37,833 39,417 41,005 41,716 42,426 43,137 43,847 44,558 45,110 45,662 46,215 8,382 Total Housing Units 220,175 229,588 239,185 243,466 247,747 252,028 256,309 260,591 263,884 267,177 270,471 50,296 Source:COMPASS(Community Planning Association of Southwest Idaho)Traffic Analysis Zone Model;City& Fire District Impact Fee Studies; TischlerBise analysis From the 2023 base year housing unit totals for incorporated Ada County,there is a projected increase of 44,844 new housing units over the next ten years.Additionally, there is a projected increase of 110,415 residents in incorporated Ada County, a 23 percent increase. Figure 184. Incorporated Ada County Residential Development Projections Ada County Base Year I Total Population 1 481,0801 502,024 523,414 532,767 542,119 551,471 560,823 570,174 577,281 584,388 591,495 110,415 Percent Increase 4.4% 4.3% 1.8% 1.8% 1.7% 1.7% 1.7% 1.2% 1.2% 1.2% 23.0% Housing Units Si ngl a Fa mi ly 159,898 166,853 173,967 177,075 180,183 183,291 186,399 189,507 191,866 194,226 196,586 36,688 Multifamily 37,266 38,822 40,383 41,072 41,761 42,450 43,139 43,828 44,359 44,891 45,423 8,156 Total Housing Units 197,164 205,676 214,350 218,147 221,944 225,741 229,538 233,334 236,226 239,117 242,008 44,844 Source:COMPASS(Community Planning Association of Southwest Idaho)Traffic Analysis Zone Model;City& Fire District Impact Fee Studies; TischlerBise analysis TischlerBise 29 FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study From the 2023 base year housing unit total for unincorporated Ada County, there is a projected increase 5,453 new housing units over the next ten years.Additionally, there is a projected increase of 14,982 residents in unincorporated Ada County, a 23.6 percent increase. Figure 195. Unincorporated Ada County Residential Development Projections Ada County Base Year I Total Population 1 63,5101 65,991 68,532 69,861 71,190 72,520 73,850 75,181 76,284 77,388 78,492 14,982 Percent Increase 3.9% 3.8% 1.9% 1.9% 1.9% 1.8% 1.8% 1.5% 1.4% 1.4% 23.6% Housing Units Si ngl a Fa mi ly 22,444 23,318 24,213 24,675 25,138 25,600 26,063 26,526 26,908 27,289 27,671 5,227 Multifamily 566 594 622 644 665 687 708 730 751 771 792 226 Total Housing Units 23,011 23,912 24,835 25,319 25,803 26,287 26,772 27,256 27,658 28,061 28,464 5,453 Source:COMPASS(Community Planning Association of Southwest Idaho)Traffic Analysis Zone Model;City& Fire District Impact Fee Studies; TischlerBise analysis TischlerBise 30 FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study CURRENT EMPLOYMENT AND NONRESIDENTIAL FLOOR AREA The impact fee study will include nonresidential development as well. Available through COMPASS Job projections from the Traffic Analysis Zone Model (TAZ) and Communities in Motion 2050 there are an estimated 239,668 jobs in Ada County in 2023.These job projections are broken down by industry leading to an estimated 43,787 retail jobs, 130,780 office jobs,35,745 industrial jobs,and 29,356 institutional jobs in the base year. Base year nonresidential floor area estimates are based on Ada County GIS nonresidential parcel data. There is an estimated 131 million square feet of nonresidential floor area in Ada County. Retail and industrial sectors account for the greatest share with approximately 32 percent each. Institutional accounts for 20 percent, and office accounts for 17 percent of the total. Figure 206.Ada County Base Year Employment and Nonresidential Floor Area Base Year %of Base Year %of Jobs[1] Total Sq.Ft.[2) Total Retail 43,787 18% 41,938,153 32% Office 130,780 55% 21,670,098 17% Industrial 35,745 15% 41,668,221 32% Institutional 29,356 12% 25,911,213 20% Total 239,668 100% 131,187,685 100% [1] COMPASS(Community Planning Association of Southwest Idaho)Traffic Analysis Zone Model;Communities in Motion 2050 [2] Source:Ada County GIS parcel data The job and nonresidential floor area estimates were further broken down into incorporated and unincorporated areas. Incorporated Ada County has an estimated 230,704 jobs in 2023. These job projections are broken down by industry leading to an estimated 42,925 retail jobs, 125,936 office jobs, 34,547 industrial jobs, and 27,296 institutional jobs in the base year. Additionally, there is an estimated 127 million square feet of nonresidential floor area in incorporated Ada County. Retail accounts for the greatest share at 32 percent. Industrial accounts for 31 percent, institutional accounts for 19 percent,and office accounts for 17 percent of the total. Figure 217. Incorporated Ada County Base Year Employment and Nonresidential Floor Area Base Year %of Base Year %of •• . .• Jobs[1] Total Sq.Ft. [2] Total Retail 42,925 19% 41,286,649 32% Office 125,936 55% 21,370,261 17% Industrial 34,547 15% 39,887,518 31% Institutional 27,296 12% 24,605,169 19% Total 230,704 100% 127,149,597 100% [1] COMPASS(Community Planning Association of Southwest Idaho)Traffic Analysis Zone Model;Communities in Motion 2050 [2] Source:Ada County GIS parcel data Tisch Bise 31 FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study Unincorporated Ada County has an estimated 8,964 jobs in 2023. These job projections are broken down by industry leading to an estimated 862 retail jobs, 4,844 office jobs, 1,198 industrial jobs, and 2,060 institutional jobs in the base year. Additionally, there is an estimated 4 million square feet of nonresidential floor area in unincorporated Ada County. Industrial accounts for the greatest share at 44 percent. Institutional accounts for 32 percent, retail accounts for 16 percent, and office accounts for 7 percent. Figure 228. Unincorporated Ada County Base Year Employment and Nonresidential Floor Area 7Retail Base Year %of Base Year %of Jobs[11 Total Sq. Ft. [2] Total 862 10% 651,504 16% 4,844 54% 299,837 7% 1,198 13% 1,780,703 44% Institutional 2,060 23% 1,306,044 32% Total 8,964 100% 4,038,088 100% [1] COMPASS(Community Planning Association of Southwest Idaho)Traffic Analysis Zone Model;Communities in Motion [2] Source:Ada County GIS parcel data EMPLOYMENT AND NONRESIDENTIAL FLOOR AREA PROJECTIONS Job projections for the industry sectors are calculated with the Institution of Transportation Engineers' (ITE) square feet per employee averages shown in Figure 239. For retail industries the Shopping Center land use factors are used; for office the General Office factors are used; for industrial the Light Industrial factors are used; for institutional the Hospital factors are used. Figure 239. Institute of Transportation Engineers(ITE) Employment Density Factors Employment • . . - Industry .. Retail 820 1 Shopping Center 1,000 Sq Ft 2.12 471 Office 710 General Office 1,000 Sq Ft 3.26 307 Industrial 110 Light Industrial 1,000 Sq Ft 1.57 637 Institutional 610 Hospital 1,000 Sq Ft 2.86 350 Source: Trip Generation, Institute of Transportation Engineers, 11th Edition (2021) T[schlerBise 32 FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study Job and nonresidential growth projections over the next ten years for Ada County are shown in Figure 30. It is estimated there will be an increase of 43,283 jobs, an 18 percent increase from the base year.The majority of the increase comes from the office sector(54 percent). The nonresidential floor area projections are calculated by applying the ITE square feet per employee factors to the job growth. In the next ten years, the nonresidential floor area is projected to increase by 17 million square feet (rounded), a 13 percent increase from the base year. The office sector has the largest share of this growth at 42 percent. Figure 30.Ada County Employment and Nonresidential Floor Area Projections Base Year Total Jobs[l] Retail 43,787 44,612 45,437 46,262 47,086 47,910 48,734 49,557 50,367 51,177 51,986 8,199 Office 130,780 133,132 135,483 137,835 140,186 142,538 144,889 147,241 149,556 151,872 154,187 23,407 Industrial 35,745 36,388 37,030 37,673 38,315 38,958 39,600 40,242 40,875 41,507 42,139 6,394 Institutional 29,356 29,884 30,413 30,943 31,472 32,003 32,533 33,064 33,588 34,113 34,639 5,283 Total 1 239,6681 244,016 248,364 252,712 257,060 261,408 265,756 270,104 274,386 278,669 282,951 43,283 Nonresidential Floor Area(1,000 sq.ft.)[2] Retail 41,938 42,327 42,715 43,104 43,492 43,880 44,268 44,656 45,037 45,419 45,800 3,862 Office 21,670 22,392 23,114 23,836 24,558 25,280 26,002 26,724 27,434 28,145 28,856 7,186 Industrial 41,668 42,078 42,487 42,896 43,305 43,715 44,124 44,533 44,936 45,339 45,741 4,073 Institutional 25,911 26,096 26,281 26,467 26,652 26,838 27,023 27,209 27,392 27,576 27,760 1,849 Total 131,1881 132,893 134,598 136,302 138,007 139,712 141,417 143,121 144,800 146,479 148,1571 16,970 [1] COMPASS(Community Planning Association of Southwest Idaho)Traffic Analysis Zone Model;Communities in Motion 2050;TischlerBise analysis [2]Source: Institute of Transportation Engineers, Trip Generation, 2021 Tisch B S@ 33 FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study Job and nonresidential growth projections over the next ten years for incorporated Ada County are shown in Figure 241. It is estimated there will be an increase of 41,040 jobs, an 18 percent increase from the base year.The majority of the increase comes from the office sector(55 percent). The nonresidential floor area projections are calculated by applying the ITE square feet per employee factors to the job growth. In the next ten years, the nonresidential floor area is projected to increase by 16.1 million square feet (rounded), a 13 percent increase from the base year. The office sector has the largest share of this growth at 43 percent. Figure 241. Incorporated Ada County Employment and Nonresidential Floor Area Projections IncorporatedAda County Base Year � Total Jobs[l] Retail 42,925 43,696 44,466 45,236 46,004 46,772 47,539 48,306 49,059 49,811 50,561 7,636 Office 125,936 128,198 130,458 132,715 134,970 137,223 139,474 141,723 143,933 146,138 148,339 22,403 Industrial 34,547 35,168 35,787 36,407 37,025 37,643 38,261 38,878 39,484 40,089 40,693 6,146 Institutional 27,296 27,786 28,276 28,765 29,254 29,742 30,230 30,718 31,197 31,675 32,152 4,856 Total 1 230,7041 234,848 238,987 243,123 247,254 251,381 255,505 259,624 263,673 267,712 271,744 41,040 Nonresidential Floor Area(1,000 sq.ft.)[2] Retail 41,287 41,650 42,013 42,375 42,737 43,099 43,460 43,821 44,176 44,530 44,883 3,597 Office 21,370 22,065 22,758 23,451 24,144 24,835 25,526 26,217 26,895 27,572 28,248 6,878 Industrial 39,888 40,283 40,678 41,072 41,466 41,860 42,253 42,646 43,032 43,418 43,802 3,915 Institutional 24,605 24,777 24,948 25,119 25,291 25,461 25,632 25,803 25,970 26,138 26,305 1,699 Total 1 127,1501 128,774 130,397 132,018 133,637 135,255 136,872 138,487 140,074 141,657 143,2381 16,088 [1] COMPASS(Community Planning Association of Southwest Idaho)Traffic Analysis Zone Model;Communities in Motion 2050;TischlerBise analysis [2]Source: Institute of Transportation Engineers, Trip Generation, 2021 34 TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study Job and nonresidential growth projections over the next ten years for unincorporated Ada County are shown in Figure 252. It is estimated there will be an increase of 2,244jobs, a 25 percent increase from the base year.The majority of the increase comes from the office sector(45 percent). The nonresidential floor area projections are calculated by applying the ITE square feet per employee factors to the job growth. In the next ten years, the nonresidential floor area is projected to increase by 881,000 square feet, a 22 percent increase from the base year. The office sector has the largest share of this growth at 35 percent. Figure 252. Unincorporated Ada County Employment and Nonresidential Floor Area Projections UnincorporatedAda County Base Year Total Jobs[1] Retail 862 916 971 1,026 1,082 1,138 1,194 1,251 1,308 1,366 1,425 563 Office 4,844 4,934 5,025 5,120 5,216 5,315 5,415 5,518 5,623 5,734 5,849 1,005 Industrial 1,198 1,220 1,243 1,266 1,290 1,314 1,339 1,365 1,391 1,418 1,446 248 Institutional 2,060 2,098 2,137 2,177 2,218 2,260 2,303 2,347 2,391 2,438 2,487 427 Total 1 8,9641 9,168 9,377 9,589 9,806 10,027 10,251 10,480 10,714 10,957 11,208 2,244 Nonresidential Floor Area(1,000 sq.ft.)[2] Retail 652 677 703 729 755 781 808 835 862 889 917 265 Office 300 327 356 384 414 444 475 507 539 573 608 308 Industrial 1,781 1,795 1,809 1,824 1,839 1,855 1,871 1,887 1,904 1,921 1,939 158 Institutional 1,306 1,319 1,333 1,347 1,361 1,376 1,391 1,406 1,422 1,438 1,456 150 Total 1 4,0381 4,119 4,201 4,285 4,370 4,457 4,545 4,634 4,726 4,821 4,920 881 [1] COMPASS(Community Planning Association of Southwest Idaho)Traffic Analysis Zone Model;Communities in Motion 2050;TischlerBise analysis [2]Source: Institute of Transportation Engineers, Trip Generation, 2021 35 TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study VEHICLE TRIP GENERATION RESIDENTIAL VEHICLE TRIPS BY HOUSING TYPE A customized trip rate is calculated for the single family and multifamily units in Ada County. In Figure 263, the most recent data from the US Census American Community Survey is inputted into equations provided by the ITE to calculate the trip ends per housing unit factor. A single family unit is estimated to generate 10.66 trip ends and a multifamily unit is estimated to generate 5.42 trip ends on an average weekday. Figure 263. Customized Residential Trip End Rates by Housing Type Households by Structure Type Tenure by Units Vehicles Single Multifamily Total Vehicles per in Structi Available' Family HH by Tenure Owner-Occupied 289,778 129,602 1,468 131,070 2.21 Renter-Occupied 85,906 24,109 29,546 53,655 1.60 Total 375,684 153,711 31,014 184,725 2.03 Housing Units3 158,890 33,161 192,051 HouseholdsPersons in Vehicles by Trip Average Local Trip National Trip Housing Type � per Unit7 Single Family 415,557 1,157,628 324,995 2,118,200 1,637,914 9.43 Multifamily 59,917 137,129 50,518 199,334 168,231 4.54 Total 475,474 1,294,757 375,513 2,317,534 1 1,806,145 1.Vehicles available by tenure from Table B25046,2021 American Community Survey 5-Year Estimates. 2. Households by tenure and units in structure from Table B25032,2021 American Community Survey 5-Year Estimates. 3. Housing units from Table B25024,2021 American Community Survey 5-Year Estimates. 4.Total population in households from Table B25033,2021 American Community Survey 5-Year Estimates. 5.Vehicle trips ends based on persons using formulas from Trip Generation(ITE 2021). For single-family housing(ITE 210),the fitted curve equation is EXP(0.89*LN(persons)+1.72).To approximate the average population of the ITE studies, persons were divided by 19 and the equation result multiplied by 19. For multi-family housing(ITE 221),the fitted curve equation is(2.29*persons)-81.02(ITE 2017). 6.Vehicle trip ends based on vehicles available using formulas from Trip Generation(ITE 2021). For single-family housing (ITE 210),the fitted curve equation is EXP(0.99*LN(vehicles)+1.93).To approximate the average number of vehicles in the ITE studies,vehicles available were divided by 34 and the equation result multiplied by 34. For multi-family housing (ITE 221),the fitted curve equation is(3.94*vehicles)+293.58(ITE 2021). 7.Trip Generation, Institute of Transportation Engineers, 11th Edition(2021). Tisch Bise 36 FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study RESIDENTIAL VEHICLE TRIPS ADJUSTMENT FACTORS A vehicle trip end is the out-bound or in-bound leg of a vehicle trip. As a result, so to not double count trips, a standard 50 percent adjustment is applied to trip ends to calculate a vehicle trip. For example,the out-bound trip from a person's home to work is attributed to the housing unit and the trip from work back home is attributed to the employer. However, an additional adjustment is necessary to capture County residents' work bound trips that are outside of the County. The trip adjustment factor includes two components. According to the National Household Travel Survey, home-based work trips are typically 31 percent of out-bound trips (which are 50 percent of all trip ends). Also, utilizing the most recent data from the Census Bureau's web application "OnTheMap", 17 percent of Ada County workers travel outside the County for work. In combination,these factors account for 3 percent of additional production trips (0.31 x 0.50 x 0.17=0.03). Shown in Figure 4, the total adjustment factor for residential housing units includes attraction trips (50 percent of trip ends) plus the journey-to-work commuting adjustment (3 percent of production trips) for a total of 53 percent. Figure 34. Residential Trip Adjustment Factor for Commuters Trip Adjustment Factor for Commuters Employed Ada County Residents(2020) 212,011 Residents Working in Ada County(2020) 175,359 Residents Commuting Outside of Ada County for Work 36,652 Percent Commuting Out of Ada County 17% Additional Production Trips 3% Standard Trip Adjustment Factor 50% Residential Trip Adjustment Factor 53% Source:U.S.Census,OnTheMap Application,2020 TischlerBise 37 FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study NONRESIDENTIAL VEHICLE TRIPS Vehicle trip generation for nonresidential land uses are calculated by using ITE's average daily trip end rates and adjustment factors found in their recently published 11th edition of Trip Generation.To estimate the trip generation in Ada County, the weekday trip end per 1,000 square feet factors listed in Figure 35275 are used. Figure 3527. Institute of Transportation Engineers Nonresidential Factors Employment ITE Demand Wkdy Trip Ends Wkdy Trip Ends Industry Code Land Use Unit per Dmd Unit I per Employee Retail 820 Shop in Center 1,000 Sq Ft 37.01 17.42 Office 710 General Office 1,000 S Ft 10.84 3.33 Industrial 110 L ht Industrial 1,000 S Ft 4.87 3.10 Institutional 610 Hospital 1,000 S Ft 10.77 3.77 Source: Trip Generation,I nstitute of Transportation Engineers,11th Edition(2021) For nonresidential land uses, the standard 50 percent adjustment is applied to office, industrial, and institutional land uses. A lower vehicle trip adjustment factor is used for retail uses because this type of development attracts vehicles as they pass-by on arterial and collector roads. For example, when someone stops at a convenience store on their way home from work, the convenience store is not their primary destination. In Figure 286, the Institute for Transportation Engineers' land use code,daily vehicle trip end rate, and trip adjustment factor is listed for each land use. Figure 286. Daily Vehicle Trip Factors ITE Daily Vehicle Trip Adj. Daily Vehicle CodesLand Use Residential(per housing unit) Single Family 210 10.66 53% 5.65 Multifamily 220 5.42 53% 2.87 Nonresidential (per 1,000 square feet) Retail 820 37.01 38% 14.06 Office 710 10.84 50% 5.42 Industrial 110 4.87 50% 2.44 Institutional 610 10.77 50% 5.39 Source: Trip Generation, Institute of Transportation Engineers, 11th Edition(2021); 'National Household Travel Survey, 2009 Tisch Bise 38 FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study VEHICLE TRIP PROJECTIONS The base year vehicle trip totals and vehicle trip projections are calculated by combining the vehicle trip end factors, the trip adjustment factors, and the residential and nonresidential assumptions for housing stock and floor area. Countywide, residential land uses account for 1,138,874 vehicle trips and nonresidential land uses account for 948,256 vehicle trips in the base year shown in Figure 297. Through 2033, it is projected that daily vehicle trips will increase by 374,018 trips with the majority of the growth being generated by single family (63 percent) and retail (15 percent) development. Figure 297.Ada County Vehicle Trip Projections Base Year Total Residential Trips Single Family 1,030:196 1,074,429 1,119,675 1,139,848 1,160,022 1,180,195 1,200,368 1,220,542 1,236,029 1,251,516 1,267,003 236,807 Multifamily 108679 113,228 117,791 119,832 121,873 123,915 125,956 127,997 129,583 131,170 132,756 24,077 Subtotal 1,138,874 1,187,658 1,237,466 1,259,681 1,281,895 1,304,110 1,326,324 1,348,539 1,365,612 1,382,685 1,399,759 260,884 Nonresidential Trips Retail 589,810 595,277 600,742 606,204 611,664 617,121 622,576 628,029 633,398 638,762 644,120 54,310 Office 117,452 121,365 125,278 129,191 133,103 137,016 140,929 144,841 148,694 152,547 156,400 38,948 Industrial 101,462 102,459 103,456 104,452 105,449 106,445 107,442 108,438 109,419 110,399 111,380 9,918 Institutional 139,532 140,528 141,524 142,522 143,521 144,520 145,520 146,521 147,509 148,498 149,489 9,957 Subtotal 948,256 959,629 971,000 982,369 993,737 1,005,103 1,016,467 1,027,830 1,039,020 1,050,206 1,061,389 113,134 Vehicle Trips Grand Total 2,087,130 2,147,286 2,208,466 2,242,050 2,275,632 2,309,212 2,342,791 2,376,368 2,404,632 2,432,892 2,461,148 374,018 Source:Institute of Transportation Engineers, Trip Generation, 11th Edition (2021) Tischleroise 39 FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study In incorporated Ada County, residential land uses account for 1,010,441 vehicle trips and nonresidential land uses account for 926,099 vehicle trips in the base year shown in Figure 308. Through 2033, it is projected that daily vehicle trips will increase by 337,251 trips with the majority of the growth being generated by single family (61 percent) and retail (15 percent) development. Figure 308. Incorporated Ada County Vehicle Trip Projections Ada County Base Year Total . 2i i24 2025 2026 2027 2028 2029 2030 2031 Residential Trips Single Family 903,389 942,688 982,879 1,000,440 1,018,000 1,035,559 1,053,117 1,070,675 1,084,006 1,097,336 1,110,670 207,281 Multifamily 107,051 111,521 116,004 117,983 119,963 121,942 123,921 125,899 127,427 128,954 130,481 23,429 Su btota 1 1,010,441 1,054,210 1,098,883 1,118,423 1,137,962 1,157,500 1,177,038 1,196,575 1,211,433 1,226,289 1,241,151 230,710 Nonresidential Trips Retail 580,647 585,754 590,856 595,953 601,044 606,131 611,213 616,291 621,280 626,259 631,228 50,580 Office 115,827 119,591 123,351 127,107 130,859 134,608 138,353 142,095 145,772 149,442 153,103 37,277 Industrial 97,126 98,089 99,050 100,011 100,970 101,929 102,887 103,843 104,784 105,722 106,658 9,532 1 nsti tuti ona 1 132,499 133,423 134,346 135,268 136,189 137,110 138,029 138,948 139,851 140,752 141,651 9,152 Subtotal 926,099 936,857 947,603 958,338 969,063 979,778 990,482 1,001,177 1,011,687 1,022,174 1,032,640 106,541 Vehicle Trips Grand Total 11,936,539 1,991,066 2,046,486 2,076,761 2,107,025 2,137,278 2,167,520 2,197,752 2,223,120 2,248,464 2,273,791 337,251 Source: Institute of Transportation Engineers, Trip Generation,11th Edition (2021) 40 TischlerBise FISCAL I ECONOMIC I PLANNING Ada County, Idaho 2024 Capital Improvement Plan and Development Impact Fee Study In unincorporated Ada County, residential land uses account for 128,434 vehicle trips and nonresidential land uses account for 22,157 vehicle trips in the base year shown in Figure 319. Through 2033, it is projected that daily vehicle trips will increase by 36,772 trips with the majority of the growth being generated by single family (80 percent) and retail (10 percent) development. Figure 319. Unincorporated Ada County Vehicle Trip Projections Ada County Base Year Total Unincorl 2023 2024 2025 2026 2027i 2031 Residential Trips Single Family 126,807 131,741 136,796 139,409 142,022 144,636 147,251 149,866 152,023 154,180 156,338 29,532 Multifamily 1,627 1,707 1,787 1,849 1,911 1,973 2,035 2,097 2,157 2,216 2,275 648 Subtotal 128,434 133,448 138,583 141,258 143,933 146,609 149,286 151,964 154,179 156,396 158,613 30,180 Nonresidential Trips Retail 91163 9,523 9,886 10,251 10,619 10,990 11,363 11,739 12,118 12,503 12,893 3,730 Office 1,625 1,774 1,927 2,084 2,244 2,408 2,575 2,746 2,922 3,106 3,297 1,672 Industrial 4,336 4,370 4,406 4,442 4,479 4,517 4,555 4,594 4,635 4,677 4,721 385 Institutional 7,033 7,105 7,178 7,254 7,331 7,410 7,491 7,573 7,658 7,746 7,838 805 Subtotal 22,157 22,772 23,397 24,031 24,673 25,325 25,985 26,652 27,333 28,032 28,749 6,592 Vehicle Trips Grand Total 150,5911 156,220 161,980 165,288 168,606 171,934 175,271 178,616 181,512 184,428 187,363 36,772 Source: Institute of Transportation Engineers, Trip Generation,11th Edition (2021) 41 TischlerBise FISCAL I ECONOMIC I PLANNING