Infrastructure: Public Sector Perspective • The Public Sector is heavily involved in infrastructure provision, monitoring, and upgrading. In considering infrastructure investments, the public sector must take into account: • --Public safety --Total cost issues --Economic development --Who benefits/who pays --Political issues --Community priorities --Growth management --Fiscal situation • In short, the public sector “must take the broadest possible view of proposed development and its implications”.
Infrastructure: The Developer’s Perspective • A developer almost always approaches a project from the “site level”. They are not nearly as interested in issues of equity, service levels, etc. as the Public Sector, unless these impact the success of a given project. • This simple difference must be kept in mind by both parties when determining project impacts and identifying necessary infrastructure upgrades. • At the site level, developers usually review (at minimum): -Topography -Climate -Soils -Vegetation -Hydrology -Local land uses -Zoning -Demand for development -Existing infrastructure
Community Infrastructure Provision • The goals and objectives of infrastructure development for a community can be properly achieved only through careful planning. • Elements integral to successful infrastructure provision include: • --A clearly articulated Comprehensive Plan with well-defined purposes and goals for development and infrastructure investments • --Explicit minimum engineering and environmental standards to guide infrastructure development • --Explicit Level of Service (LOS) Standards that identify a community’s acceptable service levels for infrastructure/urban services • --Incentives and sanctionsto be used towards achieving these goals and objectives • --A comprehensive and continuously updated information base on current conditions of existing infrastructure • --Continued monitoring and evaluation of the impacts of existing and new development on infrastructure • --Sufficient revenuesfor planning and for implementing infrastructure high-priority projects
Assessing Infrastructure Needs • The Landscape • America’s infrastructure is falling apart; bridges crumbling, sewer mains breaking, yet investment is down. Recall Week 1. • In addition, infrastructure is expanding into suburban areas, with squabbles over costs for expensive extensions of all infrastructure types. • Implications for Planners • Two Very different types of “Infrastructure Needs” 1) Replacement Infrastructure in Developed Areas 2) Infrastructure for New/Emerging Areas • Two Very different methods for determining “Infrastructure Needs”
Assessments for Existing Systems • At the heart of an Infrastructure Needs Assessment for currently developed areas is Information. • Condition Assessment: The process of measuring the physical condition of facilities, using specific, clearly defined indicators that are “observable and measurable”. • The Five Major “Condition Assessment Measures” 1) Safety and Structural Integrity: The most important factor 2) Age: Formerly one of two most important factors (along with safety) now much less important as an indicator. 3) Capacity: Existing and projected; Current and projected usage 4) Quality of Service 5) Role: The relative importance of a given facility is imperative in an assessment. Must recognize the fit of an individual component into the whole system and in relation to other systems.
Assessments for Existing Systems II • The Role of Standards 1) Standards ensure consistent approaches to assessment, 2) Compatibility of system components, 3) Can help save money by protecting from unnecessary improvements, and 4) Most importantly, provide for public safety through good engineering. • The issue is not whether design standards are required, but what level of service they represent and how flexible they are for allowing or delaying improvements. • It is important to keep in mind that for each level of service a level of investment and maintenance is required. This translates into dollar figures each year that must come from somewhere. Higher standards require higher O&M funding. • Sometimes, the planner’s role is to calculate the different levels of investment required for each level of service.
Replacement InfrastructureDecision-Making Process Step 1: Develop a System Inventory Step 2A: Establish Performance Criteria Step 2B: Conduct a Conditions Assessment Step 3: Identify Deficiencies in the System Step 4: Develop Funding Scenarios and Program Priorities Step 5: Develop and Evaluate Alternative Projects Step 6: Evaluate Program/Project Alternatives Step 7: Select Programs/Projects and Start Spending Money!!!
Assessments for New Systems • Traditionally, projected needs for New Systems or New (Suburban) Areas have been tied to population. • A number of different projection methods have been used (URP 5261 Methods III) • “Infrastructure Needs” have been estimated from these population projections. • Traditional demographic factors of importance to infrastructure planners: • Population Size (Total served population) • Population Composition (Household Sizes, Ages, Genders, etc.) • Population Distribution (Spatial location, Densities) • This system works well for some infrastructure systems that derive their demand from residential populations (for example, schools)
Assessments for New Systems Demand Side Calculations Population& Workers Infra UseMultipliers InfraDemand X = • This approach is typically used to determine the impacts of a proposed project during the permitting process. • This allows the planner to determine if facilities/services are available to service a proposed development. • For example, a developer is proposing to build 100 SF homes, half of which will be four bedroom, the other half three bedroom. What is the impact of this development on local public schools, potable water demand, and wastewater produced?
Estimating Development Parameters I • It is common for planners to be estimating the needs for new community facilities without the benefit of detailed development plans. • For instance, this is necessary when the needs are being estimated for a land use plan or for a specific development site that is still in the conceptual planning stage. • This necessitates the estimation of relevant development parameters from secondary information. • In effect, we use parameters derived from past projects or national measures to estimate: --the total number of DU’s in a proposed project --the total number of residents in a proposed project --the total number of employees in a proposed project • From these projections we can then derive demand for different infrastructure systems.
Estimating Development Parameters II Estimating Dwelling Units/Residents • For residential land uses, the calculation of infrastructure needs for many infrastructure systems (i.e. schools, water systems, sewerage systems, roads, transit, solid waste disposal, and parks) begins with an estimate of the number of dwelling units and the total population for a given area/project. • The total population expected to occupy an area is a function of the number of dwelling units, their types, and their sizes. • The number of persons per dwelling unit varies substantially by the size of the dwelling and, to a lesser extent, by the type of dwelling. • Parameters are available from the Census Bureau, from Burchell’s Development Impact Assessment Handbook, and/or can be derived locally from Census PUMS data.
Estimating Development Parameters III Estimating Non-Residential Floor Space and Employees • For non-residential uses it is common to estimate the amount of floor space and employment associated with the development of a particular site. • Floor space is usually estimated by applying a Floor Area Ratio (FAR) coefficient to the size of the site after deducting for the space needed for internal and boundary roads. • The term Floor Area Ratio is defined as “the gross floor area of all buildings on a lot divided by the lot area”. • Employment is usually estimated by applying a ratio of employees to floor space to the amount of floor space derived above. • A prime data source for this information is the Community Builders Handbook Series by the Urban Land Institute.
Infrastructure Usage Rates • It is standard practice to estimate the development-induced demand placed upon infrastructure systems by applying usage rates to development parameters discussed earlier. Usage rates are derived from the accumulation of survey research conducted in numerous areas. • Pupil Generation Rates: Pupil generation rates are provided for Elementary, Middle, and High School levels. In addition, a public school percentage should be applied as well. (B & L) • Trip Generation Rates: Different land uses and densities have different trip generation rates. Data available from ITE. • Water Usage Rates: Can be derived from formulas or surveys. Local water utility usually has a firm figure on this. • Sewer Usage Rates: Sewer system planning usually treats sewage generation as a ratio of water usage. (70% is a commonly used figure) • In addition, LOS standards are often applied to other systems. For example, a Parks standard of 6 acres per 1000 people would allow for the calculation of required Parks generated by a given project.
Assessments for New Systems Supply Side Calculations Population & Workers LOS Standards InfraSupply X = • This approach is typically used to size facilities when upgrades and additions to systems are being considered. • Using this approach, the planner can identify infrastructure shortcomings given a future population of a given size. • For example, Franklin County is expected to grow from 9,800 residents in 2000 to 14,000 residents in 2020. Do they have enough space in the schools, enough potable water, enough wastewater treatment, etc. to service this future demand?
Tallahassee LOS Standards Potable Water (Prior to Permitting) --140 gallons per capita per day (residents only) Sanitary Sewer (Prior to Permitting) --140 gallons per capita per day (residents only) Solid Waste (Prior to Permitting) --5.65 pounds per day per capita in 1990 (+.1 additional per year) Parks (Within 12 Months) --4.92 acres of ALL parkland per 1000 population (Countywide) --2.00 acres of area-wide parks per 1000 population (USA) Stormwater (Prior to Permitting) --No flood water in new buildings or existing buildings. (100 year)--The rate of off-site discharge shall not exceed the predevelopment rate of discharge. (25 year) Arterial and Collector Roads (Prior to Permitting) --LOS D during peak P.M. hour in the peak direction Source: TLCPD Concurrency Manualhttp://talgov.com/citytlh/growth/manual/contents.htm
The Concept of a Functional Population • Functional population: A measure of the equivalent population to be served by selected capital facilities that are affected by residents, workers, and visitors to an area. • Nelson and Nicholas argue that this method is useful for determining demand for certain infrastructure systems: fire, police, emergency, jail, courts, general administration. Not as useful for other systems like schools, water/sewer, and drainage. • This methodology is an example of how knowledge of local conditions can (and should) inform population projection/forecasting methods. This method takes into account local land uses and densities when calculating the “functional population” that impacts these systems.
The Concept of a Functional Population II • Generalized Formula: • Residential Pop* + Employment Pop* + • Commercial Pop* + Visiting Pop* • * All of these are standardized so that their actual “weekly weights” are determined • Implication is that by identifying the impact of employees and visitors to an area, a financing system can be devised that transfers the burden for these facilities away from just local residents. • The concept of “functional population” can help planners to design financing instruments for non-residential land uses, relating to their requirements for urban service provision. • This method also assumes that clear Levels of Service (LOS) standards are part of the planning process.