THE SMART GROWTH TWIN CITIES DEVELOPMENT SCENARIOS INDICATOR MODELING SUMMARY OVERVIEW
INFORMING THE BLUEPRINT
During the past two years, the Smart Growth Twin Cities (SGTC)
The Smart Growth Twin Cities process represents an important step
process has incorporated extensive input from public workshops,
in the development of Blueprint 2030. The Blueprint will chart a
local comprehensive plans, business associations and regional
course for future growth and development in the Twin Cities region.
transportation policy into the creation of three alternative development
The following seven objectives form the core of the Blueprint:
Scenarios for the Twin Cities Region. For the SGTC process, each
- Increase lifecycle and affordable housing
alternative future illustrates a distinct way in which the Twin Cities can
- Preserve and protect natural resources
accommodate the Region’s next 280,000 households (approximately
- Support rural communities and preserve agricultural lands
580,000 people) and 360,000 jobs.
- Provide greater transportation choices linked to development patterns and jobs
Ranging from auto-oriented to transit-oriented, the Scenarios vary in
- Reinvest in fully developed and older communities
land consumption, levels of reinvestment, walkable development,
- Invest in new, developing communities
density, and other development characteristics. The land use variations
- Focus growth and redevelopment in urban and rural centers along corridors
in each Scenario hold different consequences for regional housing diversity, transportation choice, air quality, public infrastructure costs,
By measuring the consequences of the SGTC development Scenarios,
agriculture and environmental preservation. Each Scenario has
the Metropolitan Council will be able to weigh particular advantages
undergone extensive land use and transportation modeling to measure
and disadvantages of each Scenario against these core objectives. The
these consequences and better understand the implications of various
Council can then incorporate particular elements or patterns into the
regional development patterns. These findings will serve as essential
Blueprint that align with the seven objectives, or choose to avoid
input as the Metropolitan Council develops Blueprint 2030.
patterns that are not consistent with local and regional goals.
Current Plans Scenario
Regional Workshop Scenario A
Regional Workshop Scenario B
The above figures provide a sense of land consumption in each development Scenario. The colored areas represent the newly developed land in each Scenario, also referred to as the increment. Gray represents existing developed land.
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THE SGTC DEVELOPMENT SCENARIOS
LAND CONSUMPTION
The Current Plans Scenario represents a mosaic of local comprehensive
A comparison of land consumption illustrates one of the most
plans in the region and is mainly auto-oriented. Considering the growth
dramatic differences between the development Scenarios. The Current
forecasts, local jurisdictions generally over-planned commercial land.
Plans Scenario consumes 286 square miles of land in the Region,
Likewise, local plans often did not provide enough multi-family
significantly greater than the 152 square miles developed in Regional
housing or plan for walkable development types. Thus, the Current
Workshop Scenario A and more than double the 136 square miles
Plans Scenario consists of low-density, often single-use development
developed in Regional Workshop Scenario B. Higher levels of
and little reinvestment.
reinvestment, often with higher-density development, reduced the
Regional Workshop Scenario A is derived directly from the local and
overall land consumption and development of existing agriculture
regional public workshops. Regional Workshop Scenario A balances
and undeveloped land in the Regional Workshop Scenarios.
more compact, auto-oriented development with a greater amount of
Reinvestment and density are further discussed in the following
development that is walkable, particularly along the planned 2025
sections.
Transit Network and on underutilized land in existing urban centers. It also provides more housing choices than the Current Plans Scenario.
LAND CONSUMPTION COMPARISON
Regional Workshop Scenario B is also based on public input from the workshops, but it concentrates compact, walkable centers along the Transit Network to a greater degree than Workshop Scenario A. Regional Workshop Scenario B incorporates the greatest amount of reinvestment and rural conservation development. It also provides the greatest diversity of housing. Both Regional Workshop Scenarios preserved known green corridors in the region.
ASSUMPTIONS All three Scenarios incorporate the same set of assumptions regarding environmentally constrained land. Growth was not allocated to 100year floodplains, National Wetlands Inventory wetlands and slopes greater than 18 percent. When the Metropolitan Council - Department Acres of Development
of Natural Resources (DNR) natural resources inventory and assessment is completed, the Council and the DNR can refine the
Land Consumption Agricultural Land Developed Prime Ag Soils Developed
definition of environmentally constrained lands. The same set of
Current Plans
Workshop A
Workshop B
182,922 95,205 56,885
96,972 45,884 34,419
87,173 41,342 31,953
tools was used to build each Scenario: a set of 16 development types, each with a unique number of dwelling units and jobs per acre and with a unique mix of housing and commercial land use types. These are the same development types used in the public workshops. Each Scenario assumes the same future network of highways and transit corridors (see Transportation Policy Plan, Jan. 2001), but coordinates land use with these networks to varying degrees. Finally, all three Scenarios accommodate the same increment of growth – 280,000 households and 360,000 jobs. Calthorpe Associates
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DEVELOPMENT ON AGRICULTURAL LANDS
around a shared public space. Homes can be placed on the soils most
The Current Plans Scenario develops significantly more agricultural
appropriate for septic tanks and drainage fields. The clustering of
land and prime agricultural soils than the Workshop Scenarios. The
homes saves infrastructure costs by reducing the length of roads and
agricultural land alone developed in the Current Plans Scenario is
utility lines. The remaining acres of each lot form a contiguous open
comparable to all of the new land developed in Workshop Scenario A,
space, in which 50 to 90 percent of the site can be preserved in its
and is nearly 10 percent more than all the new land developed in
natural or farmed state. Though Rural Cluster is considered as
Workshop Scenario B. In the Current Plans Scenario, nearly 57,000
“developed” land in the Scenarios, more land is actually conserved
acres (89 square miles) of prime agricultural soils were developed,
within areas designated Rural Cluster. Thus, a significant proportion
while only 34,000 (53 sq. miles) and 32,000 acres (50 sq. miles) are
of the 33 square miles of Rural Cluster in Workshop Scenario A and
developed in Workshops Scenarios A and B, respectively.
the 67 square miles in Workshop Scenario B remain undeveloped.
DEVELOPMENT ON AGRICULTURAL LAND AND PRIME AGRICULTURAL SOILS Natural Open Space (Activities Restricted) Active Open Space (Construction, fences, pets permitted) Building Site (Location & orientation restrictions)
RURAL CLUSTER
Common Open Space (Natural Features preserved where possible)
The Regional Workshop Scenarios incorporate a significant amount of rural cluster development – a form of conservation development in which more land is conserved than developed. Rather than parceling off agricultural land and ecologically-sensitive areas into uniformly large residential lots, this approach clusters homes on variable size lots
The above diagram illustrates the hierarchy of uses typical in rural cluster development
RURAL CLUSTER DEVELOPMENT
These examples of Rural Cluster Development emphasize the connection between clustered homes and the natural landscape. At left, homes are clustered around a central green, which is also accessible via trail. At right, homes face onto a preserved riparian corridor. Calthorpe Associates
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WALKABLE DEVELOPMENT The differences between each Scenario become more apparent in a comparison of specific land uses. The character of each Scenario is largely reflected in the extent to which walkable and auto-oriented development types are utilized. Walkable development – development with a mix of uses and an interconnected street network – is essential to livable communities that provide transportation choices, including driving, taking transit, walking and other modes. Auto-oriented development is often characterized by disconnected networks of streets, lower-density development and large-scale activity centers. While such activity centers are mixed-use, their scale and design are not conducive to walking.
WALKABLE DEVELOPMENT COMPARISON
Walkable development accounts for 25 percent of the households in the Current Plans Scenario. The Workshop Scenarios provide a greater diversity of housing and employment centers in walkable centers than the Current Plans Scenario. Walkable development accounts for 57 percent of households in Workshop Scenario A and 70 percent of households in Workshop Scenario B.
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RESIDENTIAL DENSITY
To more accurately depict the difference between each Scenario, the
The discussion of development scenario density incoporates both
incremental density can be divided into the Urban Service Area density
final and incremental figures. The final regional residential density*,
and the Rural Area density. The Urban Service Area Density measures
encompassing all existing development and new land to be developed
residential density within the region’s contiguous urbanized areas.
in the Scenario, does not vary significantly between the Scenarios. Thus,
The Rural Area density measures residential density outside this core
while the Regional Workshop Scenarios concentrate development along
of developed land. The Urban Service Area Density in the Current
centers and corridors and conserve natural resources, they do not
Plans Scenario is 4.3 dwelling units per acre. Due to greater reinvestment
significantly alter the all-encompassing final density. The Current Plans
and transit corridor development in the Regional Workshop Scenarios,
Scenario results in a final region-wide density of 1.32 dwelling units
the Workshop Scenario A Urban Service Area Density is 6.5 du/ac
per acre (du/ac) – near the 2000 residential density of 1.24 du/ac.
while that of Workshop Scenario B is 8.3 du/ac.
Regional Workshop Scenarios A and B result in slightly higher final
URBAN SERVICE AREA AND RURAL AREA DENSITIES
densities of 1.44 and 1.46 du/ac, respectively. Regional Densities (Dwelling Units per Residential Acre) Final Regional Density Incremental Regional Density Urban Service Area Density Rural Area Density
Current Plans 1.32 1.71 4.35 0.52
Workshop A Workshop B 1.44 1.46 3.32 3.59 6.79 8.35 0.92 1.29
The incremental density – the density of only newly developed land – does vary with each Scenario. The Current Plans incremental density is 1.71 du/ac. The Regional Workshop A incremental density is 3.32 du/ac, while that of the Regional Workshop Scenario B is 3.59 du/ac.
The Rural Area Density of 0.52 du/ac for the Current Plans Scenario
The incremental density of Regional Workshop Scenario B is most
reflects the widespread use of low-density estate and large-lot
consistent with the densities desired by most groups at the public
residential development. The Rural Area Density of .92 du/ac and
workshops.
1.29 du/ac in Regional Workshop Scenarios A and B reflect greater housing diversity and various single-family residential types in the
FINAL AND INCREMENTAL DENSITIES
Rural Areas.
The Urban Service Area Density was calculated on land within the red, inner border. The Rural Area density was calculated on the remaining land, outside of the border.
* Residential Density is equal to the number of dwelling units divided by the number of net residential acres. Calthorpe Associates
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REINVESTMENT
THE JOBS-HOUSING BALANCE
Reinvestment typically takes advantage of older, outmoded commercial
The jobs-housing balance is a meaningful way to gain a sense of how
and industrial areas and other underutilized lands, often surrounding
many people will commute to work, to or from where they will
transit corridors. In the Current Plans Scenario, 7 percent of households
commute, and how far they will have to commute. An unbalanced
and 17 percent of jobs are gained from reinvestment. The number of
jobs-housing ratio implies employees will be spending more time on
households from reinvestment doubles in Workshop Scenario A, to
roadways that may be better spent with their families or at work. One
14 percent, while 26 percent of jobs are gained from reinvestment. In
way to measure the regional jobs-housing balance is to compare the
Workshop Scenario B, 19 percent of households and 35 percent of
number of households living near a major concentration of jobs.
jobs were provided by reinvestment. Increased reinvestment is a key
Compared to the Current Plans Scenario increment, the Workshop
factor in the consequent reduction of development on sensitive
Scenario A growth increment contains roughly 30 percent more
environmental and agricultural areas in the Workshop Scenarios.
households located within 2 miles of the region’s largest employment
HOUSEHOLDS AND JOBS FROM REINVESTMENT
concentrations. Comparing Workshop Scenario B to the Current Plans Scenario, the difference is over 200 percent. The Regional Workshop Scenarios place a greater number of households near employment concentrations along transit corridors.
HOUSING MIX Recent Metropolitan Council studies have projected the demand for multi-family and single-family housing in the Twin Cities Metropolitan Region. Each Scenario meets this forecast to a different degree. The Current Plans Scenario over-supplies single-family households and under-supplies multi-family households by roughly 36 percent – more than 50,000 units. Workshop Scenario A meets the housing-type
Large Employment Concentrations in the Twin Cities Region
demand to a better degree, oversupplying single-family and undersupplying multi-family housing by approximately 15 percent.
HOUSEHOLDS NEAR EMPLOYMENT CONCENTRATIONS
Workshop Scenario B meets the single-family and multi-family housing demand forecast.
MEETING HOUSEHOLD DEMAND
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ACCESS TO PARKS AND T RAILS
ACCESS TO TRANSIT
Compared to the Current Plans Scenario, the Regional Workshop
Land use in the Scenarios is coordinated with the existing and planned
Scenarios place more households near regional parks and open space.
transit infrastructure to varying degrees. The Current Plans Scenario is
Within a 2.5 mile radius of Regional Parks, Workshop Scenario A
not necessarily oriented towards the planned regional transit network,
places 20 percent more households and Workshop Scenario B places
as this network was just emerging when most comprehensive plans
40 percent more households than the Current Plans Scenario. Within
were being completed. For example, the Current Plans Scenario places
a 5 mile radius, the Regional Workshop Scenarios both contain over
6,000 households within ¼ mile (walking distance) of planned light-
40 percent more households than the Current Plans Scenario. A
rail, express busways and other future transit corridors. More than
comparison of the households near regional and state trails also shows
13,000 households in Regional Workshop Scenario A and 23,000
great variation between the Scenarios. The households within ½ mile
households in Regional Workshop Scenario B are placed within the
of regional and state trails jump 150 percent between the Current
same area. Similarly, 40,000 households in the Current Plans Scenario
Plans Scenario and Regional Workshop Scenario A (from 13,000 to
increment are added within ¼ mile of existing bus stops, while 60,000
25,000 new households). The increase is more than the 200 percent
households and 90,000 households are placed within the same area in
from the Current Plans Scenario to Workshop Scenario B, which places
Regional Workshop Scenarios A and B. Increased transit accessibility
32,000 new households Within ½ mile of regional and state trails.
noticeably affects automobile usage, as described in the following section.
HOUSEHOLDS
AND
EMPLOYEES N EAR EXISTING TRANSIT
HOUSEHOLDS
AND
EMPLOYEES NEAR PLANNED TRANSIT
Regional Parks and Trails and State Trails
HOUSEHOLDS NEAR PARKS AND TRAILS
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TRANSPORTATION
effect – in the Regional Workshop Scenarios. Regional Workshop
Transit trips increase while automobile use generally decreases as the
Scenario A reduces the Current Plans Scenario output of CO by 66
Scenarios become more walkable and transit-oriented. Development
percent. Regional Workshop Scenario B reduces the Current Plans CO
in Workshop Scenario A provides for 185 percent more trips on transit
output by 92 percent.
than the Current Plans Scenario. In Workshop Scenario B, transit trips
EMISSIONS COMPARISON
increased by 283 percent when compared to the Current Plans Scenario. For Workshop Scenario A, this represents an increase of more than 64,000 trips and 430,000 passenger miles. For Workshop Scenario B, transit trips increase by more than 114,000 trips and passenger miles 606,000 over the Current Plans Scenario. Comparing the Regional Workshop Scenario increments to that of the Current Plans Scenario shows dramatic differences in Vehicle Trips, Miles, and Hours. Regional Workshop Scenario A reduced Vehicle Trips by 11 percent and Vehicle Miles by 13 percent - this translates into a reduction of over 204,000 Vehicle Trips and 2.2 million Vehicle Miles each day. Workshop Scenario B reduces these figures to an even greater degree, slashing Vehicle Trips by more than 265,000 and Vehicle
PUBLIC INFRASTRUCTURE COSTS
Miles by more than 3 million. Vehicle hours in congestion and free-
The cost of infrastructure further differentiates the consequences of
flow are also significantly reduced in both Workshop Scenarios. Such
the three Scenarios. The totals below incorporate the costs of regional
reductions cut person hours in vehicles by 130,000 hours and 194,000
sanitary sewer facilities, local water, sewer and stormsewer facilities
hours each day in the Regional Workshop Scenarios A and B, respectively.
(WSS), local roads, the regional transit network and regional highways.
AUTOMOBILE USE STATISTICS
Since the Current Plans Scenario develops the greatest land area with the greatest number of road-miles, its infrastructure costs are consistently higher, especially the local road and WSS facility expenditures. Regional Workshop Scenario A reduces the Current Plans infrastructure costs by $2.5 billion. Regional Workshop Scenario B reduces infrastructure costs by $3 billion.
INFRASTRUCTURE COST COMPARISON
AIR QUALITY Air quality indicators substantially improve as automobile use decreases and transit ridership increases. The Workshop Scenario A increment reduces the emissions produced in the Current Plans Scenario increment by 53 percent. Workshop Scenario B reduces emissions by 74 percent – more than 70 tons per day. Most notable is the reduction of Carbon Monoxide (CO) – a major contributor to the greenhouse Calthorpe Associates
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