Central Corridor Forecasting Methodology

Transcription

1 Central Corridor Forecasting Methodology Overview: Demographics will be developed for a base year, 2010, and two forecast years, 2020 and A straight line interpolation of the adopted CAMPO 2035 Plan county population and job control totals will be used to derive 2020 and 2030 controls for the 5 counties, from 2015 to 2025 and 2025 to Only TAZs in the Central Corridor study boundary will be adjusted for 2010, 2020, and 2030 (Refer to Map 1). o CAMPO 2010 parcel/point data will be used to establish a new base year 2010 for the existing condition and future growth allocation. o Future growth will be added to the new 2010 base numbers and replace the interpolated 2020 and 2030 numbers. County control totals from the 2035 Plan will be used for 2020 and 2030 o This growth will be redistributed based on updated parcel level goal density information o Special Generators, such as the UT Medical School, will be adjusted outside of the control totals after the allocation is done. Future growth (2010 to 2030) will be determined using the following information/assumptions: Population The new 2010 base year will be developed using 2010 Census data (non-group quarter population and occupied housing units) allocated to the parcel geography. The 2020 and 2030 population is based on allocating housing units first then multiplying them by an average parcel household size. Average household size is applied based on the parcel density. Households The following layers of data sources will be used to determine future housing growth: Each parcel is evaluated based on its likely future household capacity. Site Plans (SP) o The number of units is determined by what is planned or approved in the City s Emerging Projects dataset and/or Site Plan/Zoning case information. Specific Regulating District (SRD) o If the parcel is within a special district, like North Burnet Gateway Regulating Plan, a specific set of regulating guidelines are used to determine the number of units based on a maximum units per acre. Zoning o If the parcel is zoned for residential use the number of units is calculated using a maximum units per acre based on zoning code Future Land Use Map Mixed Use (FLUM MU)

2 o If the parcel has a future land use designation indicating a change of use, i.e. Mixed Use, the number of units is calculated based on the maximum units per acre based on its type of mixed use designation. The four layers of sources are applied in a specific order and differ by decade: Decade Situation Number of Units 2020 Existing Site Plan with identifiable units Use the Site Plan units 2020 No Site Plan but advertised units Use the advertised units 2020 Specific Regulating District (SRD) SRD Subdistrict UPA x buildable residential acreage 2020 Areas with only Zoning Zoning UPA x buildable residential acreage 2030 Existing Site Plan with identifiable units Use the Site Plan units 2030 No Site Plan but advertised units Use the Advertised units 2030 Mixed Use FLUM area Mixed Use FLUM UPA x buildable residential acreage 2030 Areas without MU FLUM but Zoning Zoning UPA x buildable residential acreage *UPA for each source in appendix The 2020 and 2030 horizon years will have a field that says Site Plan, SRD, Zoning, or FLUM MU indicating the source of the household capacity, Source_2020 and Source_2030. The household capacity will be in a field called MaxHH20 and MaxHH30. Where the MaxHH## is greater than the base year the parcel has the potential to increase. If the base year is greater than the MaxHH## the base year will be maintained throughout the forecast. Population When a parcel has a MaxHH it will also have a potential future household size, MaxHSIZE##. The MaxHSIZE is calculated based on the parcel s household density. Household Density (Units per Acre) Household Size UPA >= UPA >= 35 and < UPA >= 25 and < UPA >= 19.5 and < 25 2 UPA >= 10 and < UPA >= 5 and < UPA > 0 and < 5 3 or Base Year Household Size The potential future population will be in the MaxPOP20 and MaxPOP30 fields. The actual forecasted population will be determined during the attractiveness and allocation procedure.

3 Employment: The new 2010 base year for employment will be developed using Texas Workforce Commission 3 rd quarter 2010 data allocated to the parcel geography. At the time of this project the CAMPO 2010 Employment figures were not available at the parcel level and a draft was used. The 2020 and 2030 employment is based on allocating employees to parcels in a similar process as the population growth. Jobs The following layers of data sources will be used to determine future employment growth: Each parcel is evaluated based on its likely future commercial square footage by type of business. The square footage is then converted to number of jobs by dividing the square footage by an average number of employees per 1000 square feet. Site Plans (SP) o The amount of commercial square feet is based on what is planned or approved in the City s Emerging Projects dataset and/or Site Plan/Zoning case information. Specific Regulating District (SRD) o The amount of commercial square feet is calculated using the Floor to Area ratio designated in the SRD guidelines. o The commercial square footage is then divided by business type based on the Subdistrict type. Zoning o The amount of commercial square feet is calculated using the Floor to Area ratio designated in the zoning code. o The commercial square footage is then divided by business type based on the zoning type. Future Land Use Map Mixed Use (FLUM MU) o If the parcel has a future land use designation indicating a change of use, i.e. Mixed Use, the amount of commercial square feet is calculated using the Floor to Area ratio designated in the FLUM categories. o The commercial square footage is then divided by business type based on the type of use. The four layers of sources are applied in a specific order and differ by decade: Decade Situation Commercial Square Footage 2020 Existing Site Plan with identifiable units Use the Site Plan square footage by type 2020 No Site Plan but advertised units Use the advertised square footage by type 2020 Specific Regulating District (SRD) SRD Subdistrict FAR x buildable commercial area 2020 Areas with only Zoning Zoning FAR x buildable commercial area 2030 Existing Site Plan with identifiable units Use the Site Plan units 2030 No Site Plan but advertised units Use the Advertised units 2030 Mixed Use FLUM area Mixed Use FLUM FAR x buildable commercial area 2030 Areas without MU FLUM but Zoning Zoning FAR x buildable commercial area *FAR for each source and conversions in appendix

4 Table 1 Mean Sq Ft per Building Mean Sq Ft per Worker Employees per 1000 Sq Ft Principal Building Activity Table 4-10 Table 4-11* * Education Food Sales/Grocery 5.7 1, Food Service/Restaurant Health Care Inpatient Outpatient Lodging** , Mercantile Retail (not mall) 8.9 1, Enclosed strip malls Office Public Assembly , Public Order and Safety Religious and Worship , Service Warehouse and Storage , Other Source: Planner's Estimating Guide, Employment Land-Use Needs, Table 4-10 Totals and Means of Floorspace, and Number of Workers, 1999, pg Gross Sq Ft of total space, adapted from US Dept of Energy 2002 *Space and Land Consumption based on Downtown San Francisco, CA, 1981 study, will be used in high density uses **Hotels average 0.74 employees per room, will be used when number of rooms is known Used the following conversions for all data sources Employment Type Employees per 1000 sq ft Service 3.33 Retail 2.26 Restaurant (Retail) 5 Basic 1

5 Map 1 Study Area TAZ s outside of the study area will retain their original 2010 estimate and interpolated 2020 and 2030 numbers.

6 Allocation Procedure: An arithmetic allocation procedure was developed instead of manually distributing the growth. The parcels had to be ranked in order of attractiveness to receive the growth increments. The attractiveness rating was based on the combination of scores given for development status, auto and transit accessibility, and land vacancy status (and redevelopment potential if completed). In Excel the parcels were sorted from highest rating to lowest then divided into groups called bins. The total growth increments were divided into the bins then allocated to the parcels. The parcels received growth up to their capacity until the growth increment was depleted. Attractiveness Parameters The following attractiveness parameters were used: Existing Site Plan o 1000 points if a plan exists for that site Site Plan Status o 1000 points if a site plan has been approved o 750 points if a site plan has been proposed Building Permit o 1000 points if a building permit has been issued Auto Accessibility o 1000 point scale based on travel times in the Travel Demand Model, indexed to 1000 o Three Auto Accessibility measures were used, AutoHH, AutoWork, and AutoRetail Transit Accessibility o 1000 point scale based on travel times in the Travel Demand Model, indexed to 1000 o Three Auto Accessibility measures were used, AutoHH, AutoWork, and AutoRetail Vacant o 1000 points if the parcel is Undeveloped and Developable and shows no household or employment use Redevelopment Potential o 1000 point scale based on a combination of attributes used to determine a parcels likelihood of redevelopment FLUM MU designation 1000 points if future change of use to mixed use Parcel Size greater than? acre 1000 points if true Built Capacity Ratio - underdeveloped parcels = dividing the actual residential units built by the potential units allowed Highest Ratio receives 1000, rest are scaled down Remaining Capacity - the absolute number of additional dwelling units that could be built Highest additional amount receives 1000, rest are scaled down Investment Index - measure of how much a parcel has been improved = dividing the dollar value of the improvements by the dollar value of the land

7 The parcel with the lowest investment index value receives 1000 points, the rest are scaled down Year Built buildings built after? and before? 1000 points if within time period Other any score can be applied to account for unknown variables that contribute to a parcel s attractiveness to develop Map 2 Attractiveness Ratings (not final)

8 Distribution Curve In order to more evenly distribute the growth increment, and simulate the CAMPO Demographic Tool, a distribution curve was applied to the total growth increment. The parcels eligible for growth were sorted by attractivess from highest to lowest then divided equally into bins, 1 through 20. The distribution curve applies a percentage of the growth to each bin, with the highest percent in bin 1. Beta value= 0.04 total increment= 1,000 bin x e(x) Percent bin increment % % % % % % % % % % % % % % % % % % % % 33 total parcels= 10,000 parcels/bin= 500 user input result based on GIS

9 Post Allocation Procedure: The allocation procedure allocated all non-special generator growth which are the DA1POP, DA1HH, BASIC, RET, SERV fields in that TAZ. Once the allocation is done, and the control totals are met, the parcels need to be aggregated to the TAZ and joined to the TAZ geography. The previously listed fields then need to be filled with the new data. The POP and HH fields then need to be updated by adding the new DA1 fields by the SGZ fields. The special generator fields remained the same as the 2035 Plan Forecast: The 2020 allocation servs as the new base year to allocate growth to The same household and employment capacities were carried forward for 2030 except for when the FLUM MU source was present. Using the Max fields for 2030 and the DA1HH20, BASIC20, RET20, and SERV20 fields, each CALC field need to be updated to show the potential growth between 2020 and POP_CALC is updated by multiplying the MaxHSIZE30 and the HH_CALC fields.

10 Appendix Goal Density Assumptions, City of Austin document - draft_2013_buildout_assumptions_ck.xls