1. Nautilus Elementary School Community Garden
Photo credit: Federal Community Gardens Foundation
WHERE TO
GROW
Identifying Public
Lands Suitable for
Urban Agriculture
in the City of Federal Way,
Washington

2. 2 | P a g e
Contents
EXECUTIVE SUMMARY................................................................................................................................ 3
INTRODUCTION........................................................................................................................................... 4
METHODOLOGY.......................................................................................................................................... 5
RESULTS...................................................................................................................................................... 8
DISCUSSION ................................................................................................................................................ 9
NEXT STEPS............................................................................................................................................... 10
APPENDICES.............................................................................................................................................. 11
Appendix A. Data Dictionary................................................................................................................. 12
Appendix B. Geospatial Analysis Methodology..................................................................................... 17
Appendix C. Results Table..................................................................................................................... 25
Appendix D. Sample Site Profiles .......................................................................................................... 27
This report was prepared for Forterra and the City of Federal Way by Chris Hoffer and
Matt Dressler. Spatial analysis was conducted by Matt Dressler and Christopher Walter
using ArcGIS 10 software provided by ESRI through the Nonprofit Organization Program.
Special thanks to Kara Martin with Urban Foodlink and Kristen McIvor with the Pierce
Conservation District, as well as staff from the City of Federal Way, for their thoughtful
contributions in developing and conducting the inventory.
Please contact Forterra with any questions about this report:
901 5th Ave, Ste. 2200, Seattle, WA 98164; info@forterra.org; (206) 292-5907

3. 3 | P a g e
EXECUTIVE SUMMARY
This report describes the methodology and results of a spatial analysis to develop an inventory
of public land with the potential for urban agriculture in the City of Federal Way, Washington. In
partnership with City staff, Forterra conducted the analysis over several months in 2012 and
2013. The objective was to assess all public lands relative to a suite of characteristics that
address their potential suitability for several forms of urban agriculture. All input and result
datasets were delivered to the City in an ArcGIS geodatabase. In addition, City staff was
provided KML versions of key datasets so that they would be able to directly access and interact
with the results using Google Earth.
Using geographic information system (GIS) technology and publicly available data, Forterra
evaluated potential sites based on suitability criteria relevant to urban agriculture. These criteria
fell into several general categories: land ownership and management; land cover characteristics
and growing area; land use characteristics; topography; soil suitability; transportation access;
and neighborhood demographics.
In all, the assessment identified 362 candidate sites with a combined total of 256 acres of land
potentially suitable for urban agriculture. Among the candidate sites, 192 met the criteria for
potential cultivation: 26 met the minimum area requirements for small community gardens,
another 76 (totaling 20.5 acres) for large community gardens or food forests, and another 90
(totaling 233 acres) for urban farms. In addition, 490 acres were identified as having the
potential for agroforestry activities.
This analysis represents the first step in identifying new sites on public lands suitable for urban
agriculture. With this information, the City of Federal Way now moves to the next phase of
reviewing the results, engaging the community, gathering additional information and planning
additional urban agriculture projects for the benefit of residents.
"Almost any barrier [to urban agriculture] can be overcome by
an excited community group."
Kristin Mclvor
Community Garden Coordinator
Pierce County Conservation District

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INTRODUCTION
Healthy living in Federal Way
In 2011, the City of Federal Way was awarded a Healthy Eating Active Living grant from Seattle
King County Public Health through the Communities Putting Prevention to Work program
funded by the Centers for Disease Control and Prevention. This work involved conducting a
food landscape assessment1 to gain a better understanding of the community’s access to food,
by mapping and analyzing the retail environment, land use patterns, demographics, and street
network.
The results of this assessment demonstrated
the need for new policies and projects to
promote access to food and healthy living in
Federal Way. Key findings from the report
demonstrate that not only does Federal Way
have a high rate of adult obesity, but also that
most residents live closer to fast food
restaurants and convenience stores than to
healthy food sources like supermarkets.
Urban agriculture
As revealed by Federal Way’s food landscape assessment, many residents have limited access
to fresh produce and healthy foods. One strategy identified by the City to ensure that residents
have better access to healthy food is to increase access through urban agriculture.
Urban agriculture is an umbrella term encompassing a wide range of activities involving the
raising, cultivation, processing, marketing and distribution of food in an urban environment.
Urban agriculture includes a wide spectrum of activities such as home gardens, community
gardens, urban farms, cottage food operations, farm stands, and farmers markets
There are many reasons for municipalities to encourage urban agriculture. In addition to
improving health and nutrition by increasing access to healthy food, urban agriculture provides
environmental benefits, such as improving air and water quality, and helps to preserve
cultivatable lands. It also offers social benefits to the community such as capacity building and
creating an enhanced sense of place. Community gardens reduce family budgets, facilitate
neighborhood and community development and create opportunities for recreation, exercise
and education.
To help promote urban agriculture, the City of Federal Way received technical assistance in
2012 from Forterra, as part of the Environmental Protection Agency’s Building Blocks for
Sustainable Communities program. This technical assistance included engaging the community
in conversations about urban agriculture, amending current policies and regulatory codes, and
developing a land assessment protocol for identifying public lands that could be used for
community gardens and other forms of urban agriculture.
1
Kara E. Martin, Urban Food Link with Branden Born and Eva Ringstrom, Northwest Center for Livable Communities
and Amalia Leighton, SvR Design
http://www.urbanfoodlink.com/wp/wp-content/uploads/2011/11/FederalWayFoodLandscape.pdf
Food landscape assessment key findings
 Federal Way has the county’s third
highest adult obesity rate.
 Over 87% of the city’s land base is more
than one half mile from a super market.
 There are nearly four times as many fast
food restaurants and convenience stores
as there are supermarkets, small grocery
stores and produce vendors, combined.

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Land inventories for urban agriculture
Municipalities throughout the country have conducted inventories of publicly owned land that
may be suitable for urban agriculture. These inventories have allowed cities and residents to
identify the most promising lands for community gardens and other types of urban agriculture,
as well as to calculate potential food productivity. Other examples in the Northwest include
Seattle and King County, as well as Portland, Oregon and Vancouver, British Columbia.
In her review of recent inventories in
municipalities across the country2, Megan Horst
developed a general framework for conducting
an urban agriculture land inventory. Expanding
on this framework, Forterra worked with the City
to develop a methodology and then to conduct a
public land inventory. The purpose of this project
was to provide an initial inventory of publicly
owned lands and to identify their suitability for
urban agriculture. This built on the City’s existing
work to assess its food landscape and to adopt
policies in support of urban agriculture. The
inventory is intended to provide residents,
nonprofits, and City staff with information that can support an increase in urban agriculture and
food production. Looking ahead, the inventory has the potential to help both residents and City
planners identify and consider specific locations for different types of urban agriculture.
METHODOLOGY
Using the tools and analysis techniques available in geographic information systems (GIS),
Forterra conducted an inventory of publicly owned land in Federal Way and evaluated the
suitability of that land for urban agriculture based on a set of criteria. This process was informed
by reviewing methodologies and best practices of other land inventories conducted across the
country, with a focus on local efforts in Seattle, Portland, and Vancouver, BC.
After meeting with planning and GIS staff at the City of Federal Way, we created and prioritized
a list of suitability criteria. These criteria fit under several general categories of suitability for
urban agriculture: land ownership and management; land cover characteristics and growing
area; land use characteristics; topography; and soil suitability. Additionally, we included criteria
that extended beyond the characteristics of the site itself, such as transportation access and
demographics of the surrounding area. This additional information can be used to prioritize
potential sites based on how likely they are to benefit residents with the least amount of access
to healthy food and other benefits of urban agriculture.
Data were acquired from the City of Federal Way as well as a variety of local and federal
sources including King County, imagery from the US Department of Agriculture, LIDAR data
from the Puget Sound Lidar Consortium and 2010 US Census information. Based on factors
2
“A Review of Suitable Urban Agriculture Land Inventories.” Megan Horst, February 10, 2011.
http://www.planning.org/resources/ontheradar/food/pdf/horstpaper.pdf
Conducting a land inventory
1) Determine objectives
2) Involve stakeholders
3) Conduct inventory
a. Establish an initial set of
available lands
b. Establish suitability criteria
c. Assign scores
d. Present results
4) Plan next steps

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Minimum criteria for cultivation
 At least 2,500 square feet
 Not in a sensitive area or buffer
 Not forested*
 Average slope less than 10%
Potential cultivation category
 Small community garden (2,500 – 5,000 ft2
)
 Community garden (2,500 ft2
– 0.5 acres)
 Urban farm ( > 0.5 acres)
* Forested sites meeting other minimum criteria were
classified as potentially suitable for agroforestry.
such as the timeframe for conducting the inventory, the availability of necessary data and initial
priorities, not all potentially useful information was collected. The Appendices of this report
include both a data dictionary and detailed description of the methodology used for geospatial
analysis.
For land ownership, we catalogued the name and type of the agency with jurisdiction and
management of each property, recognizing that public properties could be owned by city,
county, state, federal government or other local entities. We included both the owner of the
property, such as the City of Federal Way, as well as the managing agency, such as the Parks
Department. Given that the City was in the process of updating its policies and codes as they
relate to urban agriculture, we also catalogued land use compatibility such as zoning and
current use.
To determine the potentially cultivatable
area of each site, we calculated the amount
of land available after excluding areas that
were deemed unsuitable for growing food.
Unsuitable areas included: impervious
surfaces (such as buildings, pavement, and
sidewalks); forested areas covered by tree
canopy; sensitive areas and their
associated buffers (wetlands, rivers and
lakes), and areas with slopes greater than
10%. Based on this information, sites were
further categorized by the size of
cultivatable area, indicating likely
appropriateness for small community
gardens, large urban farms, etc.
Importantly, no site was excluded from the inventory even if it was determined to be unsuitable
for cultivation. Although immediately cultivatable sites were of the most interest to the City, it
was agreed that many sites could be used for other forms of urban agriculture. Paved areas
could support container gardening or farmers markets, for example, while forested sites could
support agroforestry, and sites with extreme slopes might still be developed through terracing.
Soil suitability was also important to catalog, both by looking at the USDA farm soil rating as
well as potential arsenic contamination. Although arsenic occurs naturally in the environment
and is not typically of concern for urban agriculture, a copper smelting plant that operated
nearby until 1986 left significantly elevated levels of arsenic in surrounding soils, including much
of Federal Way. For each site, the area and concentration of detected arsenic contamination
was reported in parts per million based on data from the Washington State Department of
Ecology. Those sites with arsenic levels above 20 ppm (the state cleanup level) may still be
suitable for cultivation by bringing in new soil, or for other forms of urban agriculture such as
container gardening or farmers markets.
Given the unique role for urban agriculture to improve equitable food access, the City was also
interested in surrounding demographic characteristics of each site. This included identifying
areas with higher levels of poverty (with respect to both federal standards and in comparison to
the rest of the City). Additionally, the inventory includes the percentage of residents near each

7. 7 | P a g e
site who are people of color, as these individuals are disproportionately impacted by a lack of
access to healthy food.
Population density was also measured, recognizing that more dense and urban neighborhoods
stand to benefit the most from urban agriculture opportunities, given that less developed areas
are likely to have greater access to land for cultivation. Transportation accessibility was also
analyzed. This included the proximity of the site to bus service as well as a site’s active
transportation potential. This information can be helpful in determining which sites are most
accessible for transit-dependent residents.
Summary of land suitability categories and criteria
SUITABILITY CATEGORY AND RATIONALE SUITABILITY CRITERIA
Ownership and Management
To identify jurisdiction
 Ownership Jurisdiction
 Managing Agency or Department
Land Cover Characteristics and Growing Area
To determine suitability for cultivation and
type of urban agriculture
 Impervious Area
 Forested Area
 Sensitive Area
 Steep Slope Area
 Potentially Cultivatable Area
 Potentially Cultivatable Suitability
by Type
 Potential Agroforestry Area
Land Use Characteristics
To determine compatibility with current and
potential use
 Current zoning designation
 Current land use
Topography
To determine ease of developing site for urban
agriculture
 Slope
Transportation Accessibility
To determine site access by transit-dependent
residents
 Proximity to bus service
 Active Transportation Potential
Rating
Site Soil Suitability
To identify soil quality and potential for arsenic
contamination
 Potential Arsenic Pollution
 USDA Farm Soil Rating
Equity
To determine proximity to communities with
most benefit from, and least access to, urban
agriculture
 Food Equity
 Residential Density
 Ethnicity
Other Characteristics  Property Size
 Site Name

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RESULTS
Using Geographic Information Systems and data from the City of Federal Way, King County,
and Federal agencies, 362 candidate sites were identified as public land potentially suitable for
urban agriculture. Detailed results are included in the appendices, as are sample site profiles
that illustrate how the inventory can be used to determine suitability for different types of urban
agriculture.
Among the candidate sites, 192 sites covering 256 acres met the criteria for potential cultivation,
meaning that the site included at least 2,500 square feet that was not forested or impervious,
not in a sensitive environmental area, and not steeply sloped. Among these sites, 26 were most
appropriately sized for small community gardens, 76 sites (totaling 20.5 acres) for community
gardens or food forests, and 90 sites (totaling 233 acres) for larger urban farms. An additional
490 acres among 208 candidate sites were forested, with the potential for agroforestry. In this
context, food forests refer to the cultivation of edible trees and shrubs, while agroforestry refers
to the cultivation of forest products alone or in combination with agriculture.
Among the 192 sites with potentially cultivatable land:
 143 are within a ¼ mile of a bus stop
 More than 180 have a medium or high Active Transportation Potential score
 161 have soils with a USDA farm soil rating of “statewide importance” or better
 32 sites are within census tracts where 40% or more of the tract is living at 200% of the
federal poverty level
 43 sites are within census tracts with a median household income at or below $45,207,
which is 80% of Federal Way’s median household income
 104 are owned by the City of Federal Way, 31 are owned by the Federal Way School
District, and 22 are owned by the Lakehaven Utility District
 21 are public school properties, 16 are open space and 17 are vacant
Summary of key characteristics of potentially cultivatable sites
CATEGORY RESULTS
Ownership and Management  More than half are owned by the City
 100 acres are owned by the School District
Transportation Accessibility  75% are within a ¼ mile of a bus stop
Site Soil Suitability  51% have very low levels of arsenic contamination
Equity  About 22% are in neighborhoods at or below 80% of
Federal Way median household income
 3 out of 4 sites are in neighborhoods where 25% - 50%
of residents are people of color

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DISCUSSION
The reality of GIS analysis, like any modeling process, is the unavoidability of a certain amount
of error. The goal is to conduct analyses with the highest level of accuracy and precision
possible given inherent limitations in data, methods and resources available. The following is a
discussion of some known limitations in this analysis.
The first source of limitations in this analysis is related to data. For example, the arsenic
concentration and farming soil datasets are both subject to sampling error and limitations
related to the mathematical interpolation involved with their creation. The U.S. Census data
used in the analysis are three years out of date and potential inconsistencies in the record of
ownership, management purpose, site name and use will have led to inaccuracies in the
aggregation of adjacent parcels as single properties. Also, while the tree canopy dataset was
determined to be 92% accurate overall, it will underestimate the canopy in some locations and
overestimate it in others, corresponding to an overestimate or underestimate, respectively, of
the amount of potentially cultivatable area for different sites.
The analysis methodology makes a number of simplifications. The proximity of each candidate
site to the nearest bus stop is calculated as Euclidean (straight line) distance rather than the
true route taken using the existing transportation network. In addition, all areas with slopes of
greater than 10% are predicted to be unsuitable for cultivation, which may not always be the
case. Regulatory buffers around sensitive areas such as creeks and wetlands may in some
cases be suitable for cultivation and these areas will be missed in this analysis. The actual
extent of land suitable for agroforestry will in some cases be smaller than the results suggest as
the analysis does not consider the important factor of canopy density. Finally, the three Equity
characteristics (Food Equity, Residential Density and Ethnicity) reported for each site are based
on a spatial average of Census demographics reported for the surrounding neighborhood. While
this is a commonly used analysis technique - in fact, the only feasible method - it produces truly
accurate results only where household income levels, racial makeup and household density are
evenly distributed throughout the surrounding area: conditions that are rarely, if ever, present in
the real world.
Nevertheless, despite the existence of some error, this analysis should prove very useful in
narrowing the range of potential candidate sites. We recommend that inventory be used more
as a tool to identify sites for further consideration than to make exclusionary decisions or take
action based on the analysis alone. Reviewing the data using Google Earth will allow city staff
to take a first step in this direction by “virtually” ground truthing the results.

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NEXT STEPS
This land inventory represents the first step in identifying the suitability of public lands for urban
agriculture. There are many additional opportunities to share the results of the inventory and
engage the community, as well as to gather additional information and explore the suitability of
other types of land for related uses. The following are potential next steps for the City to
consider:
1. Share results and engage the community.
Inventories conducted in other communities have relied on stakeholder input to ensure the
inventory is comprehensive. Portland, for example, established a Technical Advisory
Committee consisting of city staff and members of a citizen-based Food Policy Council.
Focus groups and input from additional stakeholders, such as community garden leaders
and nonprofits, were also important in establishing land criteria and reviewing preliminary
results. Using this inventory as a starting point, there is significant opportunity to engage the
community in refinement and utilization.
2. Gather additional information.
Inventories are typically iterative, so there is opportunity to gather additional information and
refine the inventory. For example, other inventories have catalogued parking and sidewalk
access to sites, as well as proximity to existing community gardens, access to water
infrastructure, and the amount of shade or solar access for a given site. There is also
opportunity to “ground truth” potential sites; while this can be accomplished through actual
site visits, many inventories with large numbers of sites have successfully used satellite
imagery and tools such as Google Street View to save time.
3. Rank, classify and prioritize potential sites.
Engaging the community and gathering additional information will allow the City and
residents to further rank, classify, and prioritize sites. For example, medium to large sites for
community gardens or urban farms may be a high priority, as well as those sites in
neighborhoods with higher levels of poverty and lower access to healthy food. Sites with
water infrastructure and parking access, or those managed by particular agencies or
departments, may also be the most feasible to develop for urban agriculture.
4. Create an online interactive site locator to assist public in identifying and accessing
potential urban agriculture sites
In addition to training City staff on how to share information from the inventory with the
public, many communities have also turned the inventory into a publicly available,
interactive, online land locator. This empowers residents and nonprofits to identify and
conveniently explore potentially suitable lands for urban agriculture.
5. Conduct additional assessment.
This inventory is focused on the suitability of publicly owned land for urban agriculture, but
there could be other uses to consider, such as suitability for urban livestock, agro-forestry, or
community orchards. Additionally, privately-owned land may also worth identifying;
churches, for example, are regularly involved in community gardens. Other assessments
might focus on parking strips or even the food potential from private home production.

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APPENDICES
Appendix A. Data Dictionary
Appendix B. Analysis Methodology
Appendix C. Results Table
Appendix D. Site Profiles

12. Appendix A. Data Dictionary
Feature Class:
FederalWay_PublicLands_UrbanAgSuitability
Suitability Criteria
Reporting
Categories
Field Name Field Alias Field Description
Land Cover Characteristics and Growing Area
Impervious Area
unsuitable for
cultivation
< 2500 sq. ft.;
2500-5000 sq. ft.;
5000-21780 sq.
ft.; > 21780 sq. ft.
IMPR_SF IMPERVIOUS_SURFACE_S
QFT
Total area (sqft.) of site that is an
impervious surface as represented
by building footprints, pavement
and sidewalks
Steep Slope Area
likely unsuitable for
cultivation
Area SLOPE_10 STEEP_SLOPE_SQFT Total area (sqft.) of site with a
slope greater than 10%
Percent SLOPE_10PCT STEEP_SLOPE_PCT Percent of site with a slope greater
than 10%
Sensitive Area
potentially suitable for
cultivation
< 2500 sq. ft.;
2500-5000 sq. ft.;
5000-21780 sq.
ft.; > 21780 sq. ft.
SEN_AREA SENSITVE_AREA Total area (sqft.) of a site that is
covered by lakes, wetlands and
water courses and their associated
buffers
Forested Area
potentially suitable for
cultivation
Area FOR_SQFT FORESTED_SQFT Total area (sqft.) of a site that
covered by mature tree canopy.
Percent FOR_PCT FORESTED_PCT Percent of a site covered by mature
tree canopy
Potentially Cultivatable
Area
likely suitable for
cultivation
Area POTEN_CUL_SF POTENTIAL_CULTIVATIO
N_SQFT
Total area (sqft.) of a site that is
most suitable for cultivation in that
it does not include any of the
categories above (forest, sensitve,
impervious or steep slopes)

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Area POTEN_CUL_ACRE
S
POTENTIAL_CULTIVATIO
N_ACRES
Total area (acres) of a site that is
most suitable for cultivation in that
it does not include any of the
categories above (forest, sensitve,
impervious or steep slopes)
unsuitable; small
community
garden;
community
garden, food
forest; urban
farm, food forest
POTEN_CUL_SUIT POTENTIAL_CULTIVATIO
N_SUITABILITY
Suitable category of urban
agriculture based on minimum
cultivatable area requirements for
that category: unsuitable (< 2,500
sqft.); small community gardens
(2,500-5,000 sqft.); community
gardens and food forests (5,000-
21,780 sqft.); urban farms and food
forests (> 21,780 sqft.). Note that
sites that qualify for categories
with larger size requirements also
qualify for those with smaller
requirements.
Area FOR_FOOD FORESTED_FOOD Total area (sqft.) of a site that is
most suitable for cultivation but
that is covered by tree canopy
(does not include sensitive,
impervious or steep slopes).
Potentially suitable for agroforestry
or food forest cultivation.
Ownership and Management
Ownership Jurisdiction Name OWN_1 OWNERSHIP Name of government entity that
owns site
Federal, State,
County, City
OWN_TYPE OWNERSHIP_TYPE Hierarchical level of government
that owns site

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Managing Agency or
Department
Name or
abbreviation
OWN_DEPT OWNERSHIP_DEPT Name of agency or department
that manages site (e.g. DOT, Parks,
Public Works)
Land Use Characteristics
Zoning (site only) Current zoning
designation
CUR_ZONE CURRENT_ZONE City of Federal Way zoning
designation code(s)
Use Category (site only) Land use category USE_CAT USE_CITY Existing primary land use according
to City of Federal Way
Land use category USE_PRESENT USE_COUNTY Existing primary land use according
to King County Assessor
Topography
Slope 0-5%; 5-10%;
>10%
SLOPE_AVG SLOPE_AVG Average grade across entire site
categorized according to suitability
for urban agriculture (0-5% good; 5-
10% acceptable; >10% unsuitable)
Transportation Accessibility
Proximity to Bus Service <0.25 mi; 0.25-
0.5 mi; >0.5 mi
PROX_BUS PROXIMITY_BUS Straight line distance (miles) from
site to nearest bus stop

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Active Transportation
Potential Rating
Integer ATP_SCORE ATP_SCORE Numerical Score from 4-29 (low-
high) representing Active
Transportion Potential Rating for
site. Rating based on location
relative to city transportion
network as determined in study
conducted for the city of Federal
Way.
Site Soil Suitability
Potential Arsenic
Pollution
Non-Detect to
20.0 ppm; 20.1
ppm to 40.0 ppm;
40.1 ppm to 100.0
ppm; 100.1 ppm
to 200.0 ppm
ARSC_CONCEN ARSENIC_CONCENTRATI
ON
Detected arsenic soil concentration
range(s) (ppm) present in soils
within site boundary
USDA Farm Soil Rating Area SOIL_PRIME SOILS_PRIME_FARMLAND Area (sqft.) of site containing soils
designated Prime Farmland
(excellent for agriculture) by USDA
soil survey
Area SOIL_SWI SOILS_STATEWIDE_IMPO
RTANCE
Area (sqft.) of site containing soils
designated Statewide Importance
(good or acceptable for agriculture)
by USDA soil survey
Area SOIL_NOTPRIME SOILS_NOT_PRIME Area (sqft.) of site containing soils
designated as poor for agriculture
by USDA soil survey

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Equity Issues
Food Equity Yes, No EQUITY_POV200 EQUITY_POVERTY Whether or not site is located in a
Census Tract for which 40% or more
of 2010 population is living at or
below 200% of Federal Poverty
Level.
Yes, No EQUITY_MHHIN80 EQUITY_MEDINCOME Whether or not site is located in a
Census Tract for which 2010 median
household income is at or below
80% of Federal Way's median
household income
Residential Density <1:1; 1:1-4:1;
4:1-8:1; >8:1
HH_DEN HOUSING_UNITS_ACRE Average density in 2010 of housing
units per acre for all Census blocks
within a quarter mile of site
Ethnicity 0-25% minority;
25-50% minority;
50-75% minority;
>75% minority
ETH_PCTMN ETHNICITY_PCTMINOR Average percent minority
population in 2010 for all Census
blocks within a quarter mile of site
Other Characteristics
Property Size Area AREA_SF AREA_SQFT The area (sqft.) of site as
calculated by GIS
Area AREA_ACRES AREA_ACRES The area (acres) of site as
calcuated by GIS
Identification Integer SITE_ID SITE_ID Unique numeric ID for each site
Name FACILITY_NAME FACILITY_NAME Site name according to City of
Federal Way

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Appendix B. Geospatial Analysis Methodology
Goal Conduct an inventory of all public lands within the city of Federal Way to assess their suitability for Urban
Agriculture--specifically community gardens, urban farms and food forests
Scope & Deliverables Identify and assess candidate sites for their suitability based on all criteria identified in project scope.
Deliver results dataset in ArcGIS file geodatabase 9.3 format. Include all datasets utilized in analysis, a
summary of the suitability criteria and a description of the analysis methodology .
Spatial Reference GCS North American 1983 HARN
NAD 83 HARN State Plane WA North FIPS 4601 Feet
Projection: Lambert Conformal Conic
Software ArcGIS 10; XtoolsPro; Microsoft Word/Excel
Inputs From City of Federal Way GIS Department: geodatabase dated 20120803: Federal Way Property, Federal Way
School District Property, Lakehaven Utility District Property, Washington State Propety, FW_imperv,
FW_climits, FW_open_space, FW_parcels, FW_parks, FW_publicparcels, FW_special_district_prop,
FW_landuse, FW_lakes, FW_puget, FW_Soils, FW_wetlands, FW_streams, FW_ATPfin_201121,
Tacoma_SmelterPlume, 201004, FW_ortho_6inch_2007, FederalWay_ActiveTransportaionStudy_gdb dated
2011.
From Other Sources: King_blk2010_pophu, King_blk2010_sf1po3, KingCounty_BusStop_2012,
SOILS_King_SSURGO, KingLidar_DGM_6ft_2003, NAIP 2009 with near infrared band, acs_s053b19013 (2010
Tracts joined to ACS table: median household income in past 12 months in 2010 inflation adjusted dollars) and
esj_acs_area_poverty200percent (percentage of people living at 200 percent of the Federal Poverty Level in
King County by census tract) from American Community Survey/2010 U.S. Census via King County

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Action Feature Class Name Data Sources, Dates Spatial Analysis Technique Notes
Create analysis file gdb
and three feature
datasets--Inputs,
Intermediates, Results;
Include both input and
derived raster datasets
FederalWay
_UrbanAg
_LandInventory.gdb
See List Below import datasets required for analysis Ensure single
geographic
coordinate system
and projection for all
datasets utilized in
analysis
Create Candidate Sites
Feature Class
Sites
_UrAgCandidates
FW Land Public
Parcels, 20120803; FW
Land Special District
Property (including
Lakehaven Utility
properties) 20120803
Remove overlap in datasets, merge
(adjacent) parcels/polygons with same
ownership to create a "property" level
dataset.
Delete extraneous
fields and dissolve on
essential attributes,
run single to
multipart, create and
populate attribute
fields described in
suitability criteria
matrix for which
data already exists
via joins to other
FW_DBO feature
classes dated August,
2012. Create unique
site ID for each
property.
Identify USDA farm soil
attributes (type and
amount) for each site
Soils_SitesSoils SOILS_King_SSURGO,
20080605 (subset of
U.S. Dept. of
Agriculture, Natural
Resources Conservation
Service data)
Intersect candidate sites with soil data.
Dissolve on Site ID, sum areas by site for
each soil category and report areas in SQFT.
Create field for each soil type in results
dataset and populate via join.
Redefined
Coordinate System
(Project Tool) and
soil dataset did not
line up with city
limits along SE
boundary. approx 10
sites along SW
boundary have
portions of site
outside soil
intersection;

19. 19 | P a g e
Action Feature Class Name Data Sources, Dates Spatial Analysis Technique Notes
calculated soil types
and area for these
regions assuming
continuity of
adjacent NRCS soil
data and edited
intermediate dataset
before joining to
results.
Identify presence and
concentration of arsenic
in candidate site soils
Soils
_ArsenicContamination
Tacoma_SmelterPlume
, 201004; WA Dept. of
Ecology
Intersect candidate sites with smelter
plume data. Dissolve on Site ID, report
concentrations in ppm and concatenate
categories where multiple exist within a
site. Join to results.
Redefined
Coordinate System
(Project Tool) and
reported arsenic soil
concentration in ppm
as all of Federal Way
is within the ASARCO
smelter plume.
Identify sensitive areas,
water features and
other regulatory buffer
areas likely unsuitable
for any form of urban
agriculture
Landcover
_SitesSensitiveArea
FW_Streams,
FW_Wetlands,
FW_Lakes, 20120803.
Buffer streams 50 feet, buffer wetlands
with associated buffers identified in
FW_Wetlands. Exclude culverts from
stream dataset. Merge all above with lakes,
dissolve to remove any overlap, and
intersect with candidate sites. Dissolve
again on site ID and report areas in four
categories, <2500 sq ft, 2500-5000 sq ft,
5000-21780 sq ft, > 21780 sq ft.
Definition of
sensitive areas for
purposes of analysis
per conversation
with Erik Earle.

20. 20 | P a g e
Action Feature Class Name Data Sources, Dates Spatial Analysis Technique Notes
Identify impervious
surface
Landcover
_SitesImpervious
FW_Built_DBO_imperv,
20120803.
Intersect candidate sites with impervious
data. Dissolve on Site ID, SUM area field
and join to results.
Impervious data
includes building
footprints,
pavement,
sidewalks, pavement
edge. Area reported
in four categories;
<2500 sqft, 2500-
5000 sq ft, 5000-
21780 sq ft, > 21780
sq ft.
Calculate distance to
nearest bus stop
Equity
_PovertyMedianIncome
KingCounty_BusStop_20
12
Calculate Euclidian distance (straight line)
from candidate site polygons to nearest bus
stop with Near Tool. Report distance in
three categories; <0.25 mi; 0.25-0.5 mi;
>0.5 mi.
Calculate average active
transportation potential
value for each site
Transportation
_SitesATP
FW_ATPfin_201121 Convert atp raster pixel type from floating
point to integer with Integer tool, convert
raster to polygon, intersect with candidate
sites, run zonal statistics to derive mean
value for each site.
Calculate Average Slope Table: FW_SitesSlope
_ZonalStats
King_DGM6ft_2003
(Lidar)
Create slope raster, mask by city limits, run
Integer tool on raster (round all values down
to integers), then zonal statistics for each
site to identify mean value for each site.
Create new field and report average slope
in categories of 0-5%, 5-10%, > 10%;
Identify Steep Slopes
likely unsuitable for
urban agriculture
Landcover_SitesSlope10 King_DGM6ft_2003
(Lidar)
Reclassify slope raster (0-10%, 10-20%,
etc.), convert to polygon, create new
feature class with slopes 10% and greater,
intersect with sites, report area in sq. ft
and percent of site.

21. 21 | P a g e
Action Feature Class Name Data Sources, Dates Spatial Analysis Technique Notes
Calculate a weighted
average of housing units
per acre and percent
minority population for
all Census Blocks within
1/4 mile of each
candidate site.
Equity_EthnicityDensity;
Equity_EthnicityDensity_
Calculations
2010 U.S. Census Block
level data
Create subset of Census Block data that
intersects city limits polygon, add fields and
calculate area of census blocks in acres,
number of households per acre, total
minority population and percent minority
population. Buffer candidate sites 1/4
mile, add field and calculate buffer area in
acres, then intersect with census block
data. Add fields and calculate area of
intersect polygons in acres, and percent
area of buffered polygons. Add field and
multiply percent area of buffered polygon
by census block HH density to derive a
relative HH density for each intersect
polygon. Add field and multiply percent
area buffered polygon by percent minority
population to derive a relative percent
minority population for each intersect
polygon. Dissolve on site ID and SUM the
two relative percent fields described above.
Add two text fields and report
weighted/spatial HH density and percent
minority populations in categories defined
in suitability matrix. Join back to results
dataset and use the field calculator to
transfer these weighted average values for
each site.

22. 22 | P a g e
Action Feature Class Name Data Sources, Dates Spatial Analysis Technique Notes
Identify high-need
populations in FW
related to Federal
Poverty Level and
Median Household
Income: Food Equity
indicators
Equity
_PovertyMedianIncome
2006-2010 American
Community Survey,
U.S. Census Bureau;
2010 U.S Census Tract
Data augmented by
King County
Identify census tracts meeting criteria of
"high need populations" defined as 40% or
higher of census tract is living at 200%
Federal Poverty Level. Intersect candidate
sites (by centroid) with census tracts and
identify candidate sites with centroids in
tracts meeting criteria (yes, no). Then
identify census tracts meeting criteria of
"high need populations" defined as median
household income of census tract is at or
below 80% of Federal Way's median income
(FW median income in 2009, $56,509 ; 80%
is $45,207). Median Income from 2006-
2010, same period as Census Data.
Intersect candidate sites (by centroid) as
above and attribute as meeting second
criteria (yes, no).
Percent of
Population within
Census Tract living at
200% Federal Poverty
Level and Median
Household Income by
Census Tract based
on estimates from
2006-2010 American
Community Survey,
U.S. Census Bureau.

23. 23 | P a g e
Action Feature Class Name Data Sources, Dates Spatial Analysis Technique Notes
Determine the area and
percent of site covered
by tree canopy
Landcover_SitesCanopy;
Landcover_TreeCanopy
National Agricultural
Imagery Program
(NAIP), 1 meter
resolution, 4 Band
Imagery, 2009.
An image analysis and classification was run
on the NAIP imagery using the NDVI tool and
then the ISO Unsupervised Classification
tool. Steps included extracting by mask a
subset of the imagery, running the NDVI
analysis, then running the isocluster tool
creating 50 classes and assigning values to
the pixels (canopy, bare soil, other), then
reclassifying the raster and converting to
polygon. Features < 100 sq. ft. were
deleted and remaining polygons intersected
with the candidate sites. To improve the
quality of the canopy dataset, the polygons
were buffered 10 feet in all directions,
converted to lines, buffered another 10
feet, and then erasing these buffered line
polygons from the buffered tree canopy.
This technique "reclaimed" area of actual
tree canopy that was missed in the
classification--i.e shadows in areas of
contiguous tree canopy--and returned the
canopy data to its original outer dimension.
The 4-band NAIP
Imagery was
acquired from United
States Department of
Agriculture for a
small fee, given the
appropriate spatial
reference and
mosaicked together
from 4 quads
covering Federal
Way. Also, an
accuracy assessment
of the final site/tree
canopy dataset was
conducted by
generating 50
random points and
checking for data
accuracy at each
location. The
assessment found the
tree canopy
classification to be
92% accurate.

24. 24 | P a g e
Action Feature Class Name Data Sources, Dates Spatial Analysis Technique Notes
Determine area
potentially suitable for
cultivation
Landcover_SitesPotential
Cultivatable;
Landcover_SitesNonCulti
vatable
Landcover_
SitesCanopy, 2009;
Landcover
_SitesSlope10, 2003;
Landcover
_SitesSensitiveArea,
2012; Landcover
_SitesImpervious, 2012
The four "unsuitable for cultivation"
datasets (SitesCanopy, SitesSlope10,
SitesSensitiveArea, SitesImpervious) were
merged together and then dissolved to
remove overlap. An intersection with the
candidate site polygons was run yielding the
Landcover_SitesNonCultivatable feature
class. This dataset was erased from the
candidate site polygons. What remained in
the candidate was further refined by
removing polygons that overlaid athletic
fields, water, beaches and obvious shadows
as these areas were considered
uncultivatable. The remaining area became
the Landcover_SitesPotentialCultivatable
feature class. An intersection was run with
the candidate sites and the results reported
in four categories related to various forms
of urban agriculture: < 2500 sq. ft.
unsuitable; 2500-5000 sq. ft. marginally
suitable for urban gardens and food forests;
5000-21780 sq. ft. suitable for gardens and
food forests; > 21780 sq. ft. suitable for
urban farms and food forests
Determine the area
under tree canopy
potentially suitable for
agroforestry
Landcover_Forested
_PotentialFoodForest
Landcover
_SitesCanopy, 2009;
Landcover
_SitesSlope10, 2003;
Landcover
_SitesSensitiveArea,
2012; Landcover
_SitesImpervious, 2012
The SitesSlope10, SitesSensitiveArea,
SitesImpervious were merged together and
then dissolved to remove any overlap. The
resulting area was considered unsuitable for
agroforestry, erased from the
Landcover_SitesCanopy feature class,
intersected with candidate sites and then
reported in sq. ft in the results dataset as
Forested_PotentialFoodForest.

25. Appendix C. Results Table
Suitability
Category
Reporting Category
Number
of Sites
Cultivatable
Area in Acres
Notes
Potential
Cultivatable
Area
suitable for cultivation 192 256.2 Out of 362 total Candidate Sites
small community gardens 26 2.2 meets minimum area requirements for
community gardens, food forests 76 20.5 meets minimum area requirements for
urban farms, food forests 90 233.5 meets minimum area requirements for
unsuitable 170 0
agroforestry 208 492
Forested areas with 10% or less slope,
outside of sensitive areas and impervious
surfaces and 2500 sq. ft or greater
Sites with Cultivatable Area
Transportation
Accessibility
< .25 miles 143 196 straight line to nearest bus stop
.25-.5 miles 40 31 straight line to nearest bus stop
medium or high atp score 167 228 4-11 low, 12-19 medium, 20-28 high
high atp score 23 46 4-11 low, 12-19 medium, 20-28 high
Soil Suitability
potential arsenic contamination 99 134 "safe", non-detect to 20.0 ppm
potential arsenic contamination 4 3.8
"threat to public health", 100ppm or
greater
USDA Farm Soil Rating 161 121 soils of statewide importance or better
Equity -
Poverty
40% or more of census tract at 200%
FPL
32 39
sites are within census tracts meeting
criteria
census tract at or below 80% FW
MHHI
43 59
sites are within census tracts meeting
criteria
Equity –
Ethnicity
25-50% minority 144 190
A weighted average of the percent
minority population for all Census blocks
within a quarter mile of each site
50-75% minority 8 11.6
A weighted average of the percent
minority population for all Census blocks
within a quarter mile of each site

26. 26 | P a g e
Suitability
Category
Reporting Category
Number
of Sites
Cultivatable
Area in Acres
Notes
Residential
Density
4:1-8:1 38 32.1
A weighted average of household units
per acre for all Census blocks within a
1/4 mile of each site
Present Use
Public School 21 84
Vacant (Multi-family) 7 7.6
Land Use
Category
Open Space 16 46
Vacant 18 7.7
Park and Ride 5 6.7
Ownership
City of Federal Way 104 107
Federal Way School District 31 100
Lakehaven Utility District 22 15.6
King County Housing Authority 8 5.5

27. Appendix D. Sample Site Profiles
The following site profiles are examples of how the public land inventory can be used to
identify sites for potential cultivation. Each profile includes a brief description of urban
agriculture potential, Google Earth satellite and street view imagery, and select site
characteristics.
Site A) Potential Neighborhood Garden or Food Forest:
High Point Park Open Space (Site 233)
This small neighborhood site has 4,000 square feet of good soil for growing. Even for
neighbors with land to grow vegetables at home, the site could provide an excellent space for
a food forest containing fruit trees and edible shrubs.
Key Site Characteristics
 City-owned
 7,594 square feet total
 4,310 cultivatable square feet
 5-10% average slope
 Within ¼ mile of bus stop
 Low arsenic concentration and
good soil for cultivation

28. 28 | P a g e
Site B) Potential “Commuter Garden”
Redondo Heights Parks and Ride (Site 17)
This site has more than 70,000 square feet of cultivatable space. As a park and ride, it could
provide convenient access for commuters to tend crops and harvest food as part of their daily
routine.
Key Site Characteristics
 County-owned
 10 acres total
 73,109 cultivatable square feet
 0-5% average slope
 Within ¼ mile of bus stop
 In census tract at or below 80%
of Federal Way median
household income

29. 29 | P a g e
Site C) Potential Community Garden on Park Land
West Hylebos Wetlands Park (Site 32)
This 100+ acre park includes about 7,000 square feet of potentially cultivatable land at the
entrance seen below. In Seattle, the Rainier Beach Urban Farm and Wetlands is an example of
how urban agriculture can complement nearby ecosystems and open space.
Key Site Characteristics
 City-owned
 101 acres total
 32,000 cultivatable square feet
 5-10% average slope
 Within ¼ mile of bus stop