The Capacity of Hope: Developing a The Capacity of Hope: Developing a Regional Build-Out Model with GISRegional Build-Out Model with GIS

Martin Kim, Tom Harner, Kathryn Youra Polk

The Capacity of Hope: Developing a Regional Build-Out Model with GIS

Miami Valley Regional Planning Commission

September 29 - 30, 2011 | Hyatt Regency Hotel | Columbus, Ohio

Miami Valley Regional Planning Commission

• Voluntary association of governmental and non-governmental organizations in the Dayton metropolitan region in southwest Ohio

• Regional Planning Commission and Metropolitan Planning Organization (MPO) conducting transportation, land use and environmental planning

a region-based land use planning initiative to build a collective vision for the future of land

development in the Miami Valley Region

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Given the projected need for future population and job growth in our Region, where would you

like to see the Region develop?

Land Holding Capacity:A measure of the capacity (theoretical) of suitable

areas to accommodate development within the limits defined by existing infrastructure and natural

resource capabilities, often expressed in dwelling units, households, number of employees or acres

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METHODOLOGY

Basic Holding Capacity Methodology

1. Data acquisition aggregated to study area boundary size

2. Establish constraints to create ‘Net Buildable Area’

3. Develop density/intensity assumptions

4. Convert net development area into population and employment figures

1.Data acquisition aggregated to study area boundary size

2.Establish constraints to create Net Buildable Area

3.Develop Density/Intensity Assumptions

4.Convert net development area into population and employment figures

Study Area Analysis

• Multiple counties vs. single jurisdiction– Try to get data adjacent to your boundary

• Size of the Study Area changes the complexity involved

Data Needed

• Land Use Data• Parcel data• Square footage• Developed/Undeveloped/Partially Developed• Usage Share

• Socio-economic Data– Employment Data (Traffic Analysis Zones)

• Commercial • Industrial

– Census Data• Population• People per Household• Housing Unit• Count

Data Inconsistency Issues

Consistent boundaries with Blocks–TAZ Level Data aggregated down to Block level

– Parcel Level Data aggregated up to Block Level

Block 1

P1 P2

Block 1

Block 1

B1

TAZ 1

Temporal Data Issues

2000 2005

Census TAZ Parcel

2007

Year Data Gathered

Classification Issues

1.Data acquisition aggregated to study area boundary size

2.Establish constraints to create Net Buildable Area

3.Create Density/Intensity Assumptions

4.Convert net development area into population and employment figures

Remove Unsuitable Lands for Development

Issues Establishing Constraint

How unsuitable is too unsuitable for development?

Is this considered Buildable?

Or this?

Establish Constraint Solution

• Identify on the spectrum where your community’s visions match. – If focus is to preserve natural assets, slide higher

on the spectrum– If emphasis is on growing, slide lower on the

spectrum

?

Land Development Suitability Analysis

• Earlier analysis divided suitability into 4 categories based on constraints

• Removed lands only marked in most stringent category of “Unsuitable”

1.Data acquisition aggregated to study area boundary size

2.Establish constraints to create Net Buildable Area

3.Develop Density/Intensity Assumptions

4.Convert net development area into population and employment figures

Developing Density Assumptions

• What are your community’s goals? – More Walkability?

• Higher Density

– Larger Lots?• Lower Density

Large Lots Compact ?

Our Density Assumptions• Within a Block:

– Existing Density Levels would remain constant

Our Density Assumptions

- Current Land Use Shares would remain constant

How is Land Developed on That Which Has No Development?

Rural/Urban Development Issues• Will rural develop at same rate as urban? How does

this incorporate with existing land use?

Determining Regional Densities

• Delineated a boundary between areas with existing water/sewer access (urban) and areas without (rural)

• Calculate each area’s density average

• Use these averages as density for areas with no previous development

Water Sewer Access

Service

No Current Service

Existing Service

Drawing Density Assumptions

Large Lots Compact

Rural Average

Urban Average

How Much Land to Develop?

• Use historic trending levels to predict rate of non-residential development in rural areas

• Take rate of change of development from 1975-2007 and apply the same rate towards how much new land will be developed by 2040.

Historical Trends

• Adjust for error by normalizing the size of the blocks

– Percentage of development over area of total block

1.Data acquisition aggregated to study area boundary size

2.Establish constraints to create Net Buildable Area

3.Develop Density/Intensity Assumptions

4.Convert net development area into population and employment figures

Converting Acreage to People

• Buildable Res Acres x Housing Units/Acre x Population per HouseHold x Residential Vacancy Rate = Maximum # of People in Area

Convert Acreage to Jobs

• Buildable Non-Res Acres x FAR/Acre x Jobs/Acre x Non-Residential Vacancy Rate = Maximum # of Jobs in Area

Where can we get Vacancy Rate for:

Census data: subtract occupied housing units (Households) from total number of housing units (Housing Units)

Residential?

Where can we get Vacancy Rate for:

Used local market study (Gem Real Estate) and applied to sub regions within the study boundary

Non-Residential?

Post Analysis: Other Items to Consider

• What is proper amount of land for future infrastructure, schools, police, etc.?– Sources recommend anywhere from 10- 30% of

available land for public use

Questions?