An Assessment of Urban Tree Canopy in the City of Bothell, Washington
Prepared By Plan-It Geo, LLC, Arvada, Colorado
Prepared For King Conservation District and The City of Bothell, WA
Pa ge left intent ionally blank < A L L O W S L AYO U T V I E W I N WO R D. D E L E T E P R I O R T O PUBLISHING>
An Assessment of Urban Tree Canopy in the City of Bothell, WA March 2016
Prepared By Plan-It Geo, LLC, Arvada, Colorado
Acknowledgements This project was made possible by the King Conservation Districtâ&#x20AC;&#x2122;s Urban Forest Health Management and Stewardship Program In addition, special thanks go to Elizabeth Walker of the King Conservation District, and Daryn Brown for providing GIS data. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, sex, religion, age, disability, sexual orientation, marital status, family status, status as a parent (in education and training programs and activities), because all or part of an individualâ&#x20AC;&#x2122;s income is derived from any public assistance program, or retaliation. Cover Photo Credits City of Bothell, WA Prepared by Plan-It Geo, LLC
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CONTENTS EXECUTIVE SUMMARY .............................................................................................................................. 1 PROJECT FUNDAMENTALS & METHODOLOGY .......................................................................................... 3 MAPPING LAND COVER ..........................................................................................................................................................3 IDENTIFYING POSSIBLE PLANTING AND UNSUITABLE AREAS............................................................................................................3 VISUALIZING URBAN TREE CANOPY RESULTS...............................................................................................................................4 DEFINING ASSESSMENT LEVELS ................................................................................................................................................5 ASSESSMENT RESULTS & KEY FINDINGS ................................................................................................... 6 CITYWIDE LAND COVER ..........................................................................................................................................................6 CITYWIDE URBAN TREE CANOPY ..............................................................................................................................................6 PLANNING SUBAREAS .............................................................................................................................................................8 LAND USE ............................................................................................................................................................................9 SURFACE WATER MANAGEMENT AREAS ..................................................................................................................................10 SURFACE WATER SUBBASINS .................................................................................................................................................11 RIPARIAN AREAS .................................................................................................................................................................12 RIGHT-OF-WAY CITYWIDE ....................................................................................................................................................12 PARCELS ............................................................................................................................................................................13 RECOMMENDATIONS ............................................................................................................................. 14 RECOMMENDATION 1: UTILIZE ASSESSMENT RESULTS TO PRESERVE AND PROMOTE URBAN TREE CANOPY. ............................................14 RECOMMENDATION 2: DEVELOP AN URBAN FOREST MANAGEMENT PLAN TO PROVIDE A SHARED VISION. .............................................14 RECOMMENDATION 3: RELATE URBAN FORESTRY EFFORTS TO GREATER CITYWIDE INITIATIVES AND PRIORITIES. ......................................14 APPENDIX ............................................................................................................................................... 15 ACCURACY ASSESSMENT .......................................................................................................................................................15 COMPREHENSIVE ASSESSMENT AREA RESULTS ..........................................................................................................................17 City of Bothell, WA Geographic Summary: Planning Subareas ..................................................................................18 City of Bothell, WA Geographic Summary: Land Use .................................................................................................21 City of Bothell, WA Geographic Summary: Surface Water Management Areas ........................................................25 City of Bothell, WA Geographic Summary: Surface Water Subbasins ........................................................................28 City of Bothell, WA Geographic Summary: Riparian Areas ........................................................................................31 City of Bothell, WA Geographic Summary: Parcels ....................................................................................................34
FIGURES & TABLES FIGURES Figure 1: Bothell Location Map .............................................................................................................................................1 Figure 2: Five Primary Land Cover Classes generated from Aerial Imagery-based Analysis.................................................3 Figure 3: Sports Fields, Utility Easements, and Pioneer Cemetery, are considered unsuitable for planting .......................4 Figure 4: Examples of Relative Canopy Coverage by Parcel .................................................................................................4 Figure 5: Parcel Level Target Geography ..............................................................................................................................5 Figure 6: Rights-of-Way are the inverse of parcels ...............................................................................................................5 Figure 7: Planning Subareas within the Bothell City Limit ....................................................................................................5 Figure 8: Detailed Land Cover Classifications and Distribution ............................................................................................7 Figure 9: Percent of Urban Tree Canopy and Vegetated Possible Planting Area by Planning Subarea ................................8 Figure 10: UTC and PPA by Land Use ....................................................................................................................................9 Figure 11: Percent Urban Tree Canopy by Surface Water Management Area ...................................................................10 Figure 12: Percent Impervious Surface Area by Surface Water Management Area ...........................................................10 Figure 13: Highway Interchanges, Dense Housing Developments, and Agricultural Lands................................................11 Figure 14: Trees within the Right-of-Way near the Cityâ&#x20AC;&#x2122;s Municipal Court ........................................................................12 Figure 15: Percent Urban Tree Canopy by Parcel ...............................................................................................................13 Figure 16: Error Matrix for Land Cover Classifications within Bothell, WA ........................................................................16 Figure 17: Percent Urban Tree Canopy by Planning Subarea .............................................................................................19 Figure 18: Percent Possible Planting Area (Vegetation) by Planning Subarea....................................................................20 Figure 19: Land Use Categories ..........................................................................................................................................22 Figure 20: Percent Urban Tree Canopy by Land Use ..........................................................................................................23 Figure 21: Percent Possible Planting Area (Vegetation) by Land Use .................................................................................24 Figure 22: Percent Urban Tree Canopy by Surface Water Management Area ...................................................................26 Figure 23: Percent Possible Planting Area (Vegetation) by Surface Water Management Area .........................................27 Figure 24: Percent Urban Tree Canopy by Surface Water Subbasin ..................................................................................29 Figure 25: Percent Possible Planting Area (Vegetation) by Surface Water Subbasin .........................................................30 Figure 26: Percent Urban Tree Canopy by Riparian Area ...................................................................................................32 Figure 27: Percent Possible Planting Area (Vegetation) by Riparian Area ..........................................................................33 Figure 28: Percent Urban Tree Canopy by Parcel ...............................................................................................................34 Figure 29: Percent Possible Planting Area (Vegetation) by Parcel ......................................................................................35 TABLES Table 1: Generalized Land Cover Classification Results ........................................................................................................6 Table 2: Urban Tree Canopy Assessment Results .................................................................................................................6 Table 3: Top 3 Planning Subareas for Percent of Urban Tree Canopy ..................................................................................8 Table 5: Lowest 3 Surface Water Subbasins for Percent of Urban Tree Canopy ................................................................11 Table 6: Lowest 3 Riparian Areas for Percent of Urban Tree Canopy .................................................................................12 Table 7: Assessment Results by Citywide Right-of-Way .....................................................................................................12 Table 8: Planning Subarea Assessment Results ..................................................................................................................18 Table 9: Land Use Assessment Results ...............................................................................................................................21 Table 10: Surface Water Management Area Assessment Results ......................................................................................25 Table 11: Surface Water Subbasin Assessment Results......................................................................................................28 Table 12: Riparian Area Assessment Results ......................................................................................................................31
EXECUTIVE SUMMARY The City of Bothell is located in both King and Snohomish Counties northeast of Seattle, Washington. According to estimates from the U.S. Census Bureau’s Population Division, Bothell has grown from 33,613 people in 2010 to 41,630 people in 2015, representing an 8.8 percent increase. These Bothell residents have stressed the importance of “achieving harmony between the built and natural environments”, a “commitment to the conservation of scarce natural resources”, and the “protection of native wildlife habitats”, as expressed in the revised Imagine Bothell… Comprehensive Plan (adopted in 2015). Stormwater runoff is also important to manage as it flows into the Sammamish River, Lake Washington, and the Puget Sound. Trees and urban forests contribute positively to all of these goals; enhancing the urban environment, providing clean air and wildlife habitats, and mitigating stormwater runoff. As the population of Bothell grows and development pressures continue well into the future, it is important to identify the natural resources that exist today so that policies can be established to protect these valuable Figure 1: Bothell Location Map assets. Urban canopy studies provide a top down view of the urban forest (Source: Esri Basemap) and quantify this resource at various geographic scales in addition to identifying potential planting opportunities for future canopy growth. The King Conservation District and the City of Bothell are being proactive in their efforts to preserve Bothell’s natural resources by conducting this assessment. The primary objective of this Urban Tree Canopy Assessment in the City of Bothell, WA is to map the current extent of Bothell’s urban tree canopy to raise awareness of its value and promote its protection.
45%
21%
32%
Average Citywide Tree Canopy Cover
Vegetated Possible Planting Area
Impervious, including buildings and roads
Urban Tree Canopy in Bothell Results of this study show that of Bothell’s 8,741 total acres, 45 percent was covered by tree canopy (with 3,926 acres), 22 percent was grass and open space (with 1,936 acres), and 32 percent was impervious (with 2,765 acres). Of the grass and open space, 1,831 acres have been identified as land that provides opportunity for addition tree canopy. This Possible Planting Area (PPA Vegetation) makes up 21 percent of the City. Dividing the impervious surfaces into more detailed classifications shows that nine percent of the City is covered by buildings and nine percent is covered by roads, leaving 13 percent classified as “Other Impervious”, including parking lots and sidewalks that may offer opportunities for new trees and additional canopy cover.
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Assessment Boundaries and Analysis Results This study assessed Urban Tree Canopy (UTC) and Possible Planting Areas (PPA) at multiple geographic scales in order to provide actionable information to multiple audiences. By identifying what resources and opportunities exist at these scales, the King Conservation District and the City can be more proactive in their approach to protect (or expand) the urban tree canopy. Metrics were generated at the following geographies: the citywide boundary, planning subareas, land use, surface water management areas, surface water subbasins, riparian areas, parcels and Right-of-Way. Results show that the Fitzgerald / 35th SE Planning Subarea currently boasts the greatest percentage of UTC with 60 percent. The Waynita / Simonds / Norway Hill follows with 54 percent relative UTC, and as the largest Planning Subarea, it also has the greatest amount of total canopy with 804 acres, making up 20 percent of the entire city’s UTC. The Little Bear Creek and Parr Creek Surface Water Management Areas have the least amount of UTC with 27 percent and 36 percent, respectively. While the Little Swamp Creek SWMA has the most relative UTC at 65 percent, it is the smallest physical area and yields the least amount of acreage of UTC, with only 21 total acres and comprising only one percent of the City’s entire urban tree canopy. Aside from two subbasins with extensive agriculture, the Little Bear Creek, Northeast Sammamish, and Park n’ Ride Basins have the lowest amounts of relative UTC with 27 percent, 29 percent, and 30 percent UTC, respectively. Despite the low amounts of UTC, these areas offer only moderate amounts of planting opportunity due to high percentages of impervious surfaces. These surfaces, which include areas like roads and buildings, additionally increase stormwater runoff and the need for effective surface water management. In all riparian corridors except for three, UTC is above 50 percent. The three under 50 percent include Middle Creek, the Sammamish River, and Horse Creek. Both the Juanita West Creek and the Southwest Sammamish riparian areas contain 100 percent UTC. The total ROW land area in Bothell is 1,325 acres, of which 317 contain UTC, or 24 percent of the ROW. This ROW urban tree canopy makes up eight percent of the City’s total UTC, while the UTC within parcel boundaries make up the remaining 92 percent. More specifically, 51 percent of the City’s total tree canopy is found on single- and multi-family residential land uses, with 12 percent found on private open space and 16 percent on vacant, undeveloped lands. While city-owned open space and other government park/open space average 86 and 81 percent tree canopy cover respectively, this makes up just 9 percent of citywide total UTC.
Recommendations While there are no official adopted plans that promote the urban tree canopy, it is clear that the City values its natural resources and wants to maintain a healthy and sustainable urban environment. Therefore, it is recommended that the City utilize these assessment results to preserve and promote healthy urban tree canopy, develop an urban forest management plan that provides a shared vision and relate urban forestry efforts to greater citywide initiatives/priorities. These recommendations are a starting point for an interdisciplinary goal-setting process and determination of priorities and strategies.
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PROJECT FUNDAMENTALS & METHODOLOGY This section describes the methods through which land cover, urban tree canopy, and possible planting areas were mapped. This is fundamental, as these datasets are the basis for the metrics reported at the selected target geographies.
Mapping Land Cover The most fundamental component of this urban tree canopy assessment is the creation of an initial land cover data set. The process began with the acquisition of 2015 high-resolution (1-meter) aerial imagery from the USDA’s National Agricultural Imagery Program (NAIP). An object-based image analysis (OBIA) software program called Feature Analyst (ArcGIS Desktop) was used to classify features through an iterative approach, where objects’ spectral signatures across four bands (blue, green, red, and near-infrared), textures, and pattern relationships were taken into account. This process resulted in five initial land cover classes as shown in Figure 2. After manual classification improvement and quality control, additional data layers from the city, (such as buildings, roads, and other impervious surfaces) were utilized to capture finer feature detail and further categorize the land cover dataset.
Urban Tree Canopy
Non-Canopy Vegetation
Impervious Surfaces
Bare Soil
Water Bodies
Tree cover when viewed and mapped from above
Grass and open space vegetation
Hard surfaces where rainfall cannot permeate
Not included in possible planting areas
Bodies of water removed from total land cover
Figure 2: Five Primary Land Cover Classes generated from Aerial Imagery-based Analysis
Identifying Possible Planting and Unsuitable Areas Once the land cover dataset was finalized and the existing Urban Tree Canopy was established, Possible Planting Areas for both vegetation and impervious surfaces were then derived from the Non-Canopy Vegetation and Impervious land cover classes. “Unsuitable” areas were incorporated into the data set to identify where it is not feasible to plant trees. The City of Bothell provided GIS data delineating these unsuitable areas, which included sports fields, utility easments, and Pioneer Cemetery (as shown in Figure 3). Roads and buildings, also provided by the City, were isolated from the impervious surfaces and identified as “unsuitable impervious”. Thus, the final results are reported with vegetated possible planting areas (PPA-Veg), impervious possible planting areas (PPAIA), total possible planting areas (To-PPA), unsuitable impervious (roads and buildings), other unsuitable (sports fields, etc), and total unsuitable. BOTHELL, WA URBAN CANOPY: PROJECT FUNDAMENTALS & METHODOLOGY
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Figure 3: Sports Fields, Utility Easements, and Pioneer Cemetery, are considered unsuitable for planting
Visualizing Urban Tree Canopy Results Maps showing urban tree canopy (UTC) in this report express relative levels of canopy as a percentage of land area (not including water). UTC levels are divided into meaningful categories for each of the assessment area boundaries and may vary slightly depending on the distribution within the target geographies. For Parcels, UTC levels are broken up into four classes: 20 percent or Less UTC, 21-40 percent UTC, 41-70 percent UTC, and Greater than 70 percent UTC. Figure 4 provides visual examples of what the varying levels of UTC look like against the aerial imagery, all shown at the same scale of 1:2,400.
14% UTC (low)
27% UTC
56% UTC
82% UTC (High)
Figure 4: Examples of Relative Canopy Coverage by Parcel
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Defining Assessment Levels In order to better inform various stakeholders (city officials, city staff, and citizens alike), urban tree canopy and associated information was calculated for a variety of geographic boundaries. These include the citywide boundary, planning subareas, land use, surface water management areas, surface water subbasins, riparian areas, parcels and Right-of-Way. Outputs include total area (in acres or square feet) and relative values (as percentages) for urban tree canopy (UTC), possible planting areas (PPA), impervious surfaces, and unsuitable areas. Assessment levels include the following geographic boundaries: The City of Bothell municipal boundary is the one (1) main overarching area of interest for which all metrics are summarized. Thirteen (13) Planning Subareas were evaluated to identify the amount of tree canopy as it relates to the Planning Department, and to help inform planning management (Figure 7). The Cityâ&#x20AC;&#x2122;s Land Use Classes were created and analyzed to represent current human uses and land characteristics, totaling 10 classifications. Twelve (12) Surface Water Management Areas (SWMA) were analyzed to evaluate where UTC is lacking and where it could be expanded to assist in stormwater management efforts. Metrics for Surface Water Subbasins show the various levels of canopy and possible planting area within each watershed. Given treesâ&#x20AC;&#x2122; potential to mitigate stormwater runoff by intercepting precipitation, it is helpful to know which areas are lacking in UTC and have opportunities to grow additional tree canopy. Riparian Areas were identified by buffering 34 streams by 100 feet, capturing their surrounding areas, including plant habitats and communities along river margins and banks. Citywide Right-of-Way (ROW) covers the area where parcels are lacking, including street ROW and the river corridor. Generally, this is land that is managed by the City and the UTC results can inform City tree planting and management efforts (Figure 6). Parcels are the finest level of detail for which metrics were generated. UTC and PPA is reported for over 12,000 individual properties, including residential and commercial (Figure 5).
Figure 5: Parcel Level Target Geography (scale = 1:8,000)
Figure 6: Rights-of-Way are the inverse of parcels (scale = 1: 8,000)
BOTHELL, WA URBAN CANOPY: PROJECT FUNDAMENTALS & METHODOLOGY
Figure 7: Planning Subareas within the Bothell City Limit (scale = 1:196,000)
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ASSESSMENT RESULTS & KEY FINDINGS This section presents the key findings of this study, including the land cover base map as well as the canopy analysis results, which were analyzed across various geographic assessment boundaries. These results, or metrics, help inform a strategic approach to identifying future planting areas. Complete assessment results for target geographies and additional maps can be found in the Appendix.
Citywide Land Cover In 2015, 45 percent of Bothell was covered by tree canopy, 22 percent was grass and open space, and 32 percent was impervious. Further dividing the impervious surface areas into more detailed classifications shows that nine percent of the City is covered by buildings and nine percent is covered by roads, leaving 13 percent classified as “Other Impervious”. This remaining 13 percent includes parking lots and sidewalks, which may offer opportunities for new tree plantings and additional canopy cover. Table 1 shows the generalized land cover results, while Figure 8 shows the more detailed map and distribution. Table 1: Generalized Land Cover Classification Results
Total Acres
Tree Canopy (acres)
Tree Canopy %
Grass / Open Space (acres)
Grass / Open Space %
Impervious (acres)
Impervious %
Water (acres)
Water %
Soil / Dry Vegetation (acres)
Soil / Dry Vegetation %
8,741
3,926
45%
1,936
22%
2,765
32%
65
0.7%
49
0.6%
Citywide Urban Tree Canopy This urban tree canopy assessment utilized the land cover map as a foundation to determine Possible Planting Areas (PPA) throughout the City. Additional layers and information regarding land considered unsuitable for planting was also analyzed. It should be noted that the results of this study are based off of land area, not total area (note the difference between Total Acres in Table 1 and Land Area in Table 2). Results show that within the City of Bothell, WA, 3,926 acres are cover by urban tree canopy (UTC), making up 45 percent of the 8,676 land acres, and 1,831 acres of land has been identified as non-canopy vegetation that provides the possibility for addition tree canopy. This Possible Planting Area (PPA Vegetation) makes up 21 percent of the City. Nonbuilding and non-road impervious areas cover 1,158 acres that may also offer additional planting opportunity (PPA Impervious), while 20 percent of the City’s land has been identified as unsuitable for planting. This includes sport fields, golf course fairways, buildings and roads, and soil/dry vegetation. Table 2: Urban Tree Canopy Assessment Results *Land Area (acres)
UTC (acres)
UTC %
PPA Vegetation (acres)
PPA Vegetation %
PPA Impervious (acres)
PPA Impervious %
Total Possible Planting (acres)
Total Possible Planting %
Unsuitable UTC* (acres)
Unsuitable UTC* %
8,676
3,926
45%
1,831
21%
1,158
13%
2,989
34%
1,761
20%
*Note: Percentages are based on Land Area
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Land Cover in Bothell, WA
Figure 8: Detailed Land Cover Classifications and Distribution
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Planning Subareas This study assessed urban tree canopy (UTC) totals and Possible Planting Areas (Vegetation, Impervious, and Total PPA) for 13 Planning Subareas. The Fitzgerald / 35th SE Planning Subarea currently boasts the greatest percentage of UTC with 60 percent canopy coverage. The Waynita / Simonds / Norway Hill Subarea follows with 54 percent relative UTC, but as the largest Planning Subarea, it also has the greatest amount of total canopy with 804 acres. This large Planning Subarea contains 20 percent of the entire cityâ&#x20AC;&#x2122;s UTC. Table 3: Top 3 Planning Subareas for Percent of Urban Tree Canopy
Planning Subarea
Land Area (acres)
UTC (acres)
UTC %
PPA Veg (acres)
PPA Veg %
PPA IA (acres)
PPA IA %
Total PPA (acres)
Total PPA %
Fitzgerald / 35th SE
445
268
60%
94
21%
30
7%
124
28%
Waynita / Simonds / Norway Hill
1,478
804
54%
286
19%
132
9%
418
28%
Country Village / Lake Pleasant / Bothell-Everett Hwy
285
151
53%
50
18%
40
14%
90
31%
In terms of possible planting area and opportunities to expand the urban tree canopy, Westhill has the greatest relative amount of PPA Vegetation with 20 percent (206 acres), while Waynita / Simonds / Norway Hill offers the most actual area with 286 acres of PPA Veg.
Figure 9: Percent of Urban Tree Canopy and Vegetated Possible Planting Area by Planning Subarea
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Land Use This study processed urban tree canopy (UTC) totals and Possible Planting Areas (Vegetation, Impervious, and Total PPA) data for Bothell land use classes. Ten generalized land use classes were created to reflect current human use and land cover information as they relate to UTC. City-owned Open Space and Other Governmentowned Park/Open Space land use have the highest canopy cover at 86 percent and 81 percent, respectively. However, these two classes make up a combined 9 percent of all canopy citywide, while Single Family Land Use properties average 45 percent canopy cover, accounting for 44 percent of all canopy in the study area. The greatest opportunities to expand the urban tree canopy are within Single Family and Private Open Space land use classifications. Both classifications contain 27 percent PPA Vegetation. Government/Public Facility (26 percent) and City-owned Park (19 percent) classes also present significant opportunity for canopy growth, most of which is city-owned and managed. Vacant-Undeveloped land use contributes 16 percent of total city-wide urban tree canopy and a significantly high overall UTC of 70 percent. This classification, it should be noted, will diminish in size with future development as land use within this classification changes. Opportunities to preserve existing UTC within this classification should be considered as this land is absorbed into other land use categories as a result of future development. See maps in the Appendix of UTC and PPA by land use.
Percent of UTC and PPA (V) by Land Use Class 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0%
86%
81% 70%
69%
40% 27% 19% 13%
50%
45% 32%
29%
26% 15%
14%
27%
25% 13%
17%
17%
Urban Tree Canopy (%) Possible Planting Area (Veg) (%)
Figure 10: UTC and PPA by Land Use
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Surface Water Management Areas This study processed urban tree canopy (UTC) totals and Possible Planting Areas (Vegetation, Impervious, and Total PPA) data for 12 Surface Water Management Areas (SWMA). The Little Bear Creek SWMA and Parr Creek SWMAs have the least amount of UTC with 27 percent and 36 percent, respectively. While the Little Swamp Creek SWMA has the most relative UTC at 65 percent, it is the smallest physical area and yields the least amount of acreage of UTC, with only 21 total acres (comprising only one percent of the Cityâ&#x20AC;&#x2122;s entire urban tree canopy). It should also be noted that the Little Bear Creek and Parr Creek SWMAs also have the greatest percentages of impervious surface areas, with Little Bear at 48 percent impervious and Parr Creek at 40 percent impervious. Of these impervious surfaces, 21 acres in Little Bear and 170 acres in Parr Creek may be suitable for new canopy, meaning they are not buildings or roads. Considering the benefits of tree canopy in helping manage stormwater runoff, this may be a good approach to locating areas to consider adding tree canopy. Figure 11: Percent Urban Tree Canopy by Surface Water Management Area
Figure 12: Percent Impervious Surface Area by Surface Water Management Area CITY OF BOTHELL, WA ASSESSMENT RESULTS & KEY FINDINGS
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Surface Water Subbasins This study processed urban tree canopy (UTC) totals, and Possible Planting Area (PPA) data for 36 Surface Water Subbasins that intersect Bothell, as delineated and provided by the City. Findings at a watershed level can be used for any number of different studies and projects, including hydrologic modeling tools, water resource management plans, forest management plans, water quality studies, and more.
Figure 13: Highway Interchanges, Dense Housing Developments, and Agricultural Lands Contribute to areas of Low Urban Tree Canopy
Two subbasins with the lowest relative amounts of UTC, Swamp Creek South and Little Swamp Creek South, located on the western edge of the City, appear to have low UTC due to agricultural activity. These subbasins also have a high percentage of vegetated possible planting area (PPA-Veg), which is the result of open fields being used for agriculture. While agricultural land was not removed from the unsuitable areas identified in the study, these areas may not actually offer opportunity for additional tree canopy if they are being actively farmed. Aside from those two subbasins*, the Little Bear Creek, Northeast Sammamish, and Park nâ&#x20AC;&#x2122; Ride Basin have the lowest amounts of relative UTC, with 27 percent, 29 percent, and 30 percent UTC, respectively. Despite the low amounts of UTC, these areas only offer moderate amounts of planting opportunity since they contain some of the highest percentages of impervious surfaces, such as roads and buildings, increasing stormwater runoff and the need for surface water management. These results are shown in Table 4. For complete results, refer to the Appendix section of this report. Table 4: Lowest 3 Surface Water Subbasins for Percent of Urban Tree Canopy (*after those containing agricultural land) Land Area (acres)
UTC (acres)
UTC %
PPA Veg (acres)
PPA Veg %
PPA Impervious (acres)
PPA Impervious %
Total Impervious (acres)
Total Impervious %
Little Bear Creek
127
34
27%
27
22%
21
16%
61
48%
Northeast Sammamish
133
38
29%
34
26%
17
13%
57
43%
Park'n Ride Basin
161
49
30%
40
25%
29
18%
69
43%
Surface Water Subbasin
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Riparian Areas This study processed urban tree canopy (UTC) totals and Possible Planting Areas (Vegetation, Impervious, and Total PPA) data for all riparian areas within Bothell. Riparian areas are part of river and stream corridors, including plant habitats and communities along river margins and banks. For this study, riparian areas were identified by buffering all stream centerlines by 100 feet. UTC is above 50 percent in all riparian corridors, except for 3. These bottom 3 are identified in Table 5 and include those areas surrounding Middle Creek, the Sammamish River, and Horse Creek. Both the Juanita West Creek and the Southwest Sammamish riparian areas contain 100 percent UTC. Table 5: Lowest 3 Riparian Areas for Percent of Urban Tree Canopy Land Area (acres)
UTC (acres)
% UTC
PPA Vegetation (acres)
% PPA Vegetation
PPA Impervious (acres)
PPA Impervious %
Middle Creek
27
11
40%
7
25%
4
16%
Sammamish River
48
21
45%
19
39%
4
8%
Horse Creek
78
37
48%
10
13%
15
19%
Riparian Area
Right-of-Way Citywide Urban Tree Canopy (UTC) totals and Possible Planting Areas (Vegetation, Impervious, and Total PPA) have been evaluated for citywide Right-of-Way (ROW). The total ROW land area in Bothell (excluding water) is 1,325 acres, of which 317 contain UTC, or 24 percent of the ROW. This urban tree canopy makes up 8 percent of the Cityâ&#x20AC;&#x2122;s total UTC, while the UTC within parcel boundaries make up the remaining 92 percent. Within the ROW, an additional 216 acres of vegetated possible planting area still remains, and 131 acres of Figure 14: Trees within the Right-of-Way near the Cityâ&#x20AC;&#x2122;s Municipal Court possible planting area within impervious surfaces. (Source: Bing Maps) This includes sidewalk areas where planting pits can be established, similar to the planting pits along the south side of NE 183rd Street as shown in Figure 15. Because ROW is owned and managed by the City, possible planting areas located within them are easy targets for increasing tree canopy cover. Table 6: Assessment Results by Citywide Right-of-Way Citywide Land Area (acres)
ROW Area Land (acres)
UTC (acres)
UTC in ROW %
Citywide Distribution of ROW UTC %
PPA Veg (acres)
% PPA Veg
PPA Impervious (acres)
% PPA Impervious
Total Possible Planting (acres)
Total Possible Planting %
1,330
1,325
317
24%
8%
216
16%
131
10%
347
26%
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Parcels The most detailed assessment geography analyzed for this study was the parcel layer. This study calculated urban tree canopy (UTC) totals and Possible Planting Areas (Vegetation, Impervious, and Total PPA) for each individual property with over 12,000 records. Due to the size of the dataset, comprehensive data have been provided to the City in GIS format, and are not included in tabular format in this report.
Figure 15: Percent Urban Tree Canopy by Parcel
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RECOMMENDATIONS While there are no official adopted plans that promote efforts to grow the urban tree canopy and Bothell lacks an established urban forestry program, it is clear that the City values its natural resources and wants to maintain a healthy and sustainable urban environment. As such, the City should use these suggestions, along with the key findings in this report, as a starting point for an interdisciplinary goal-setting process and determination of priorities and strategies.
Recommendation 1: Utilize assessment results to preserve and promote urban tree canopy. This assessment report provides detailed information about current UTC and possible planting areas, both citywide and at various geographic scales. These results should be utilized to enhance and promote forest preservation and management efforts, including the establishment of a baseline urban tree canopy cover percentage. The King Conservation District and the City of Bothell should disseminate the data from this study to diverse partners for urban forestry and other applications while they are current and most useful for decisionmaking and implementation planning.
Recommendation 2: Develop an urban forest management plan to provide a shared vision. These assessment results should be used to encourage investment in forest monitoring, maintenance, management, and in preparing supportive information for local budget requests/grant applications. The information from this study can help establish canopy cover goals for the short and long term. In addition, it is recommended that the City hire an arborist, city forester, or urban forester to increase inspection, maintenance, and enforcement. Having a professional ISA certified arborist on staff is one first step in identifying and addressing forest management needs.
Recommendation 3: Relate urban forestry efforts to greater citywide initiatives and priorities. The City of Bothellâ&#x20AC;&#x2122;s urban forest green infrastructure is providing a great deal of benefits to the City that can be quantified. These benefits often relate back to greater community concerns and citywide initiatives and priorities. For example, air and water quality, stormwater management, and energy savings and all benefits that come from the urban forest. The City should use the USDAâ&#x20AC;&#x2122;s i-Tree suite of software, along with the results of this study, to measure the value of its current urban tree canopy.
BOTHELL, WA URBAN CANOPY: RECOMMENDATIONS
14
APPENDIX Accuracy Assessment Classification accuracy serves two main purposes: First, accuracy assessments provide information to technicians producing the classification about where processes need to be improved and where they are effective. Secondly, measures of accuracy provide information about how to use the classification and how well land cover classes are expected to estimate actual land cover on the ground. Even with high resolution imagery, very small differences in classification methodology and image quality can have a large impact on overall map area estimations. The classification accuracy error matrix illustrated in Figure 16 contains confidence intervals that report the high and low values that could be expected for any comparison between the classification data and what actual, on the ground land cover was in 2015. This accuracy assessment was completed using high resolution aerial imagery, with computer and manual verification. No field verification was completed. The internal accuracy assessment was completed in five (5) steps 1. Approximately one thousand (1,000) sample points were randomly distributed across the study area and assigned a random numeric value. 2. Each sample point was then referenced using the NAIP imagery and assigned one of the five land cover classes (“Ref_ID”) mentioned above. 3. In the event that the reference value could not be discerned from the imagery, the point was dropped from the accuracy analysis. In this case, no points were dropped. 4. An automated script was then used to assign values from the classification raster to each point (“Eval_ID”). The classification supervisor provides unbiased feedback to quality control technicians regarding the types of corrections required. Misclassified points (where reference ID does not equal evaluation ID) and corresponding land cover are inspected for necessary corrections to the land cover1. Accuracy is re-evaluated (repeat steps 3 & 4) until an acceptable classification accuracy is achieved.
Sample Error Matrix Interpretation Statistical relationships between the reference pixels (representing the true conditions on the ground) and the intersecting classified pixels are used to understand how closely the entire classified map represents the Bothell, WA landscape. The error matrix shown in Figure 16 represents the intersection of reference pixels manually identified by a human observer (columns) and classification category of pixels in the classified image (rows). The gray boxes along the diagonals of the matrix represent agreement between the two pixel maps. Off-diagonal values represent the number pixels manually referenced to the column class that were classified as another category in the classification image. Overall accuracy is computed by dividing the total number of correct pixels by the total number of pixels reported in the matrix (422 + 178 + 270 + 2 + 9 = 881 / 1,000 = 88 percent), and the matrix can be used to calculate per class accuracy percent’s. For example, 422 points were manually identified in the reference map as Tree Canopy, and 467 of those pixels were classified as Tree Canopy in the classification 1
Note that by correcting locations associated with accuracy points, bias is introduced to the error matrix results. This means that matrix results based on a new set of randomly collected accuracy points may result in significantly different accuracy values. BOTHELL, WA URBAN CANOPY: APPENDIX
15
map. This relationship is called the “Producer’s Accuracy” and is calculated by dividing the agreement pixel total (diagonal) by the reference pixel total (column total). Therefore, the Producer’s Accuracy for Tree Canopy is calculated as: (422/467 = .90), meaning that we can expect that ~90 percent of all tree canopy in the Bothell, WA study area were classified as Tree Canopy in the classification map.
Figure 16: Error Matrix for Land Cover Classifications within Bothell, WA
Conversely, the “User’s Accuracy” is calculated by dividing the number agreement pixel total by the total number of classified pixels in the row category. For example, 422 classification pixels intersecting reference pixels were classified as Tree Canopy, but 21 pixels were identified as Vegetation and 9 pixels were identified as Impervious in the reference map. Therefore, the User’s Accuracy for Tree Canopy is calculated as: (422/452 = 0.93), meaning that ~93 percent of the pixels classified as Tree Canopy in the classification were actual tree canopy. It is important to recognize the Producer’s and User’s accuracy percent values are based on a sample of the true ground cover, represented by the reference pixels at each sample point. Interpretation of the sample error matrix results indicates this land cover, and more importantly, tree canopy, were accurately mapped in Bothell, WA. The largest sources of classification confusion exist between tree canopy and vegetation, and vegetation and impervious.
Results Interpretation of the sample error matrix results indicates this land cover (and more importantly, tree canopy) was accurately mapped in Bothell, WA. The largest sources of classification confusion exist between tree canopy and vegetation, and vegetation and impervious.
BOTHELL, WA URBAN CANOPY: APPENDIX
16
Comprehensive Assessment Area Results This Urban Tree Canopy (UTC) Assessment of Bothell, WA was conducted by Plan-It Geo, LLC for King Conservation District and the City of Bothell. The assessment summarized metrics for a variety of target geographies. Metrics were calculated in acres and percent for Urban Tree Canopy (UTC), Possible Planting Area Vegetation (PPA Vegetation), Possible Planting Area Impervious (PPA Impervious), Total Possible Planting Area (Total PPA), and Areas Unsuitable for Planting (Unsuitable). This section provides results for each target geography, as well as maps showing the distribution of the results. Analysis results and additional maps are provided as follows: 1. 2. 3. 4. 5. 6.
Planning Subareas Land Use Surface Water Management Areas Surface Water Subbasins Riparian Areas Parcels
BOTHELL, WA URBAN CANOPY: APPENDIX
17
City of Bothell, WA Geographic Summary: Planning Subareas This table summarizes UTC metrics for Bothell, WA Planning Subareas in Acres and percent including Urban Tree Canopy (UTC), Possible Planting Area Vegetation (PPA Vegetation), Possible Planting Area Impervious (PPA Impervious), Total Possible Planting Area (Total PPA), and Areas Unsuitable for Planting (Unsuitable) Table 7: Planning Subarea Assessment Results
Planning Subarea Bloomberg Hill Brickyard Road / Queensgate Canyon Creek / 39th SE
Total Land Acres
UTC Acres
UTC %
Dist. of UTC %
PPA (Veg.) Acres
PPA (Veg.) %
PPA (Imp.) Acres
PPA (Imp.) %
Total PPA Acres
Total PPA %
Unsuit able UTC (acres)
Unsuit able UTC %
297
84
28%
2%
69
23%
42
14%
111
37%
102
34%
459
176
38%
4%
88
19%
59
13%
148
32%
135
30%
356
176
49%
4%
63
18%
51
14%
114
32%
66
19%
1,004
436
43%
11%
176
17%
205
20%
380
38%
187
19%
Country Village / Lake Pleasant / Bothell-Everett Hwy
285
151
53%
4%
50
18%
40
14%
90
31%
44
15%
Downtown
510
201
39%
5%
85
17%
107
21%
193
38%
116
23%
Fitzgerald / 35th SE
445
268
60%
7%
94
21%
30
7%
124
28%
53
12%
Maywood / Beckstrom Hill
896
346
39%
9%
223
25%
110
12%
333
37%
218
24%
North Creek / 195th
879
363
41%
9%
151
17%
170
19%
321
36%
196
22%
798
356
45%
9%
194
24%
81
10%
275
35%
167
21%
569
287
50%
7%
146
26%
52
9%
198
35%
84
15%
1,478
804
54%
20%
286
19%
132
9%
418
28%
256
17%
698
277
40%
7%
206
30%
79
11%
285
41%
136
19%
8,673
3,925
45%
100%
1,831
21%
1,158
13%
2,989
34%
1,760
20%
Canyon Park
Queensborough / Brentwood / Crystal Springs Shelton View / Meridian / 3rd SE Waynita / Simonds / Norway Hill Westhill
Total
BOTHELL, WA URBAN CANOPY: APPENDIX
18
City of Bothell, WA Geographic Summary: Planning Subareas
Figure 17: Percent Urban Tree Canopy by Planning Subarea
BOTHELL, WA URBAN CANOPY: APPENDIX
19
City of Bothell, WA Geographic Summary: Planning Subareas
Figure 18: Percent Possible Planting Area (Vegetation) by Planning Subarea
BOTHELL, WA URBAN CANOPY: APPENDIX
20
City of Bothell, WA Geographic Summary: Land Use This table summarizes UTC metrics for Bothell, WA Land Use Classifications in Acres and percent including Urban Tree Canopy (UTC), Possible Planting Area Vegetation (PPA Vegetation), Possible Planting Area Impervious (PPA Impervious), Total Possible Planting Area (Total PPA), and Areas Unsuitable for Planting (Unsuitable). Table 8: Land Use Assessment Results Total Area (Acres)
Land Area (Acres)
UTC (Acres)
UTC %
Distribution of UTC %
City-owned Open Space
194
194
167
86%
4.6%
City-owned Park
69
68
27
40%
0.7%
Other Government-owned Park/Open Space
227
207
167
81%
4.6%
Private Open Space
625
610
420
69%
11.6%
1,036
1,033
299
29%
8.3%
122
122
39
32%
1.1%
Single Family
3,494
3,478
1,579
45%
43.7%
Multi Family
513
511
258
50%
7.1%
School
296
296
73
25%
2.0%
Vacant - Undeveloped
836
833
580
70%
16%
7,411
7,351
3,609
49%
100%
Land Use
Commercial / Church Government / Public Facility
Totals
PPA Veg (Acres)
PPA Veg %
PPA Impervious (Acres)
PPA Impervious %
To PPA (Acres)
To PPA %
City-owned Open Space
24
13%
2
1%
26
13%
0
0%
City-owned Park Other Government-owned Park/Open Space
13
19%
6
9%
19
29%
22
32%
29
14%
7
3%
36
17%
4
2%
Private Open Space
166
27%
11
2%
176
29%
14
2%
Commercial / Church
156
15%
372
36%
527
51%
206
20%
Government / Public Facility
32
26%
31
25%
63
52%
20
16%
Single Family
943
27%
378
11%
1,321
38%
579
17%
Multi Family
65
13%
77
15%
142
28%
111
22%
School
49
17%
99
33%
148
50%
74
25%
Vacant - Undeveloped
139
17%
44
5%
183
22%
70
8%
1,616
22%
1,027
14%
2,642
36%
1,100
15%
Land Use
Totals
BOTHELL, WA URBAN CANOPY: APPENDIX
Total Unsuitable UTC
Total Unsuitable UTC %
21
City of Bothell, WA Geographic Summary: Land Use
Figure 19: Land Use Categories
BOTHELL, WA URBAN CANOPY: APPENDIX
22
City of Bothell, WA Geographic Summary: Land Use
Figure 20: Percent Urban Tree Canopy by Land Use BOTHELL, WA URBAN CANOPY: APPENDIX
23
City of Bothell, WA Geographic Summary: Land Use
Figure 21: Percent Possible Planting Area (Vegetation) by Land Use
BOTHELL, WA URBAN CANOPY: APPENDIX
24
City of Bothell, WA Geographic Summary: Surface Water Management Areas This table summarizes UTC metrics for Bothell, WA Surface Water Management Areas in Acres and percent including Urban Tree Canopy (UTC), Possible Planting Area Vegetation (PPA Vegetation), Possible Planting Area Impervious (PPA Impervious), Total Possible Planting Area (Total PPA), and Areas Unsuitable for Planting (Unsuitable). Table 9: Surface Water Management Area Assessment Results Total Land Acres
UTC Acres
UTC %
Dist. of UTC %
PPA (Veg.) Acres
PPA (Veg.) %
PPA (Imp.) Acres
PPA (Imp.) %
Total PPA Acres
Total PPA %
Unsuit able UTC (acres)
Unsuit able UTC %
Boy Scout Creek
505
255
50%
6%
103
20%
49
10%
152
30%
99
20%
Canyon Park
798
347
43%
9%
140
18%
166
21%
306
38%
145
18%
SWMA
Fitzgerald
435
259
59%
7%
95
22%
33
7%
128
29%
49
11%
1,586
649
41%
17%
339
21%
248
16%
588
37%
349
22%
Juanita
437
205
47%
5%
80
18%
48
11%
128
29%
104
24%
Little Bear Creek Little Swamp Creek Little Swamp Creek Parr Creek
127
34
27%
1%
27
22%
21
16%
48
38%
45
35%
884
377
43%
10%
271
31%
88
10%
359
41%
148
17%
33
21
65%
1%
5
15%
2
5%
7
20%
5
15%
889
320
36%
8%
171
19%
170
19%
341
38%
227
26%
Queensborough
1,543
678
44%
17%
340
22%
196
13%
537
35%
328
21%
787
414
53%
11%
133
17%
80
10%
213
27%
160
20%
651
367
56%
9%
126
19%
57
9%
183
28%
101
16%
8,675
3,926
45%
100%
1,831
21%
1,158
13%
2,989
34%
1,761
20%
Horse Creek
Riverside Waynita Total
BOTHELL, WA URBAN CANOPY: APPENDIX
25
City of Bothell, WA Geographic Summary: Surface Water Management Areas
Figure 22: Percent Urban Tree Canopy by Surface Water Management Area
BOTHELL, WA URBAN CANOPY: APPENDIX
26
City of Bothell, WA Geographic Summary: Surface Water Management Areas
Figure 23: Percent Possible Planting Area (Vegetation) by Surface Water Management Area
BOTHELL, WA URBAN CANOPY: APPENDIX
27
City of Bothell, WA Geographic Summary: Surface Water Subbasins This table summarizes UTC metrics for Bothell, WA Surface Water Subbasins in Acres and percent including Urban Tree Canopy (UTC), Possible Planting Area Vegetation (PPA Vegetation), Possible Planting Area Impervious (PPA Impervious), Total Possible Planting Area (Total PPA), and Areas Unsuitable for Planting (Unsuitable). Table 10: Surface Water Subbasin Assessment Results Total Land Acres
UTC Acres
UTC %
Dist. of UTC %
Total PPA Acres
Total PPA %
Unsuita ble UTC (acres)
Blyth Creek
21
19
89%
0.5%
2
8%
1
Boy Scout Creek
106
55
52%
1%
17
16%
11
3%
2
10%
0.2
1%
11%
28
26%
23
22%
Brickyard Creek
164
62
38%
2%
31
19%
23
14%
54
33%
48
29%
Cougar Creek
258
91
35%
2%
60
23%
Crystal Creek
232
128
55%
3%
46
20%
48
19%
108
42%
58
23%
22
9%
68
29%
36
16%
E. Riverside Creek
136
57
42%
1%
18
Filbert Creek
31
12
39%
0.3%
8
13%
16
12%
34
25%
45
33%
26%
3
11%
12
38%
7
24%
Horse Creek
735
326
44%
8%
143
19%
115
16%
258
35%
150
20%
Juanita Creek
477
218
46%
Juanita West
4
4
95%
6%
89
19%
54
11%
143
30%
116
24%
0.1%
0.2
4%
0.0
1%
0.2
5%
0.0
0%
Junco Creek
134
57
42%
Little Bear Creek
127
34
27%
1%
24
18%
31
23%
55
41%
22
17%
1%
27
22%
21
16%
48
38%
45
35%
Little Swamp Creek
396
178
45%
5%
115
29%
40
10%
155
39%
64
16%
Little Swamp Creek S.
122
Little Swamp Northwest
88
27
22%
1%
55
45%
14
12%
69
56%
26
21%
39
45%
1%
26
30%
7
9%
33
38%
15
17%
Maltby Hill Creek
303
181
60%
5%
40
13%
36
12%
76
25%
46
15%
Middle Creek
263
85
32%
2%
51
19%
70
27%
121
46%
57
22%
North Creek
969
472
49%
12%
205
21%
128
13%
333
34%
164
17%
Northeast Sammamish
133
38
29%
1%
34
26%
17
13%
51
38%
44
33%
Northwest Sammamish
211
94
45%
2%
52
24%
23
11%
74
35%
42
20%
Palm Creek
102
51
50%
1%
22
21%
11
11%
33
32%
18
18%
Park'n Ride Basin
161
49
30%
1%
40
25%
29
18%
68
42%
44
27%
Parr Creek
726
254
35%
6%
131
18%
149
21%
280
39%
193
27%
Perry Creek
695
284
41%
7%
152
22%
99
14%
251
36%
160
23%
Queensborough Creek
383
147
38%
4%
92
24%
49
13%
141
37%
95
25%
Surface Water Subbasin
PPA (Veg.) Acres
PPA (Veg.) %
PPA (Imp.) Acres
PPA (Imp.) %
Unsuit able UTC %
Red Basin
23
7
33%
0.2%
4
17%
5
21%
9
38%
7
29%
Riverside Creek
122
79
65%
2%
22
18%
7
6%
29
24%
14
11%
Royal Anne Creek
286
159
56%
4%
65
23%
20
7%
85
30%
41
15%
Sammamish R. Norway Hill
231
152
66%
4%
35
15%
21
9%
55
24%
24
11%
Southeast Sammamish
78
34
43%
1%
18
23%
8
11%
26
33%
18
23%
Southwest Sammamish
148
99
67%
3%
34
23%
5
3%
39
26%
10
7%
Spring Stream
151
83
55%
2%
37
24%
13
9%
50
33%
18
12%
Swamp Creek
38
23
61%
1%
7
18%
2
6%
9
24%
6
15%
Swamp Creek South
37
3
9%
0.1%
27
73%
1
4%
28
77%
5
14%
Waynita Creek Woods (Cole) Creek
495 79 8,663
263 58 3,922
53% 73% 45%
7% 1% 100%
90 14 1,830
18% 18% 21%
51 3 1,153
10% 4% 13%
141 17 2,983
29% 21% 34%
90 4 1,758
18% 5% 20%
Total
BOTHELL, WA URBAN CANOPY: APPENDIX
28
City of Bothell, WA Geographic Summary: Surface Water Subbasins
Figure 24: Percent Urban Tree Canopy by Surface Water Subbasin
BOTHELL, WA URBAN CANOPY: APPENDIX
29
City of Bothell, WA Geographic Summary: Surface Water Subbasins
Figure 25: Percent Possible Planting Area (Vegetation) by Surface Water Subbasin
BOTHELL, WA URBAN CANOPY: APPENDIX
30
City of Bothell, WA Geographic Summary: Riparian Areas This table summarizes UTC metrics for Bothell, WA Riparian Areas in Acres and percent including Urban Tree Canopy (UTC), Possible Planting Area Vegetation (PPA Vegetation), Possible Planting Area Impervious (PPA Impervious), Total Possible Planting Area (Total PPA), and Areas Unsuitable for Planting (Unsuitable). Table 11: Riparian Area Assessment Results Unsuita ble UTC (acres)
Total Land Acres
UTC Acres
UTC %
Dist. of UTC %
PPA (Veg.) Acres
PPA (Veg.) %
PPA (Imp.) Acres
PPA (Imp.) %
Total PPA Acres
Total PPA %
Boy Scout Creek
11
9
77%
1%
1
8%
0.4
3%
1
11%
1
12%
Brickyard Creek
10
5
55%
1%
1
12%
1
9%
2
21%
2
24%
Cole/Woods Creek
21
17
81%
2%
3
14%
0.4
2%
3
16%
1
3%
Cougar Creek
9
7
75%
1%
1
11%
0.5
5%
2
16%
1
8%
Crystal Creek
31
27
90%
4%
2
5%
1
2%
2
7%
1
3%
E. Riverside Creek
19
16
85%
2%
1
6%
1
3%
2
9%
1
6%
East Fork Waynita Creek
35
26
72%
3%
5
13%
1
4%
6
18%
4
10%
Riparian Area
Unsuita ble UTC %
Filbert Creek
6
5
74%
1%
0.2
3%
0.2
3%
0.4
6%
1
20%
Horse Creek
78
37
48%
5%
10
13%
15
19%
25
32%
16
20%
Juanita Creek
72
54
75%
7%
7
10%
3
4%
10
14%
8
11%
Juanita West Creek
0.5
0.5
100%
0.1%
0.0
0%
0.0
0.0%
0.0
0.0%
0.0
0.0%
Junco Creek
21
13
61%
2%
3
12%
4
16%
6
28%
2
11%
Little Swamp Creek
49
31
62%
4%
10
21%
3
6%
13
27%
5
10%
Maltby Hill Creek
43
33
77%
4%
4
8%
3
6%
6
15%
4
9%
Middle Creek
27
11
40%
1%
7
25%
4
16%
11
41%
5
20%
North Creek
130
92
71%
12%
30
23%
3
2%
32
25%
6
4%
North Creek Tributary
36
29
79%
4%
6
16%
1
2%
6
17%
1
4%
North Fork Perry Creek
38
24
63%
3%
3
9%
4
11%
8
20%
7
17%
Northwest Sammamish
5
3
74%
0.4%
1
11%
0.2
5%
1
17%
0.4
10%
Norway Hill Creek
5
5
84%
1%
0.5
9%
0.2
3%
1
12%
0.2
4%
Palm Creek
21
16
78%
2%
2
10%
1
5%
3
15%
2
7%
Parr Creek
62
36
57%
5%
10
17%
5
9%
16
26%
11
17%
Perry Creek
45
32
70%
4%
7
16%
2
3%
9
19%
5
10%
Queensborough Creek
44
31
71%
4%
6
13%
3
6%
8
19%
4
10%
Riverside Creek
39
32
81%
4%
4
11%
1
3%
6
14%
2
5%
Royal Anne Creek
70
50
70%
7%
13
18%
2
3%
15
21%
6
8%
Sammamish River
48
21
45%
3%
19
39%
4
8%
23
48%
3
7%
South Fork Perry Creek
19
14
75%
2%
2
12%
0.5
2%
3
14%
2
10%
Southeast Sammamish
9
6
68%
1%
2
20%
0.3
4%
2
23%
1
8%
Southwest Sammamish
2
2
100%
0.2%
0.0
0%
0.0
0.0%
0.0
0.0%
0.0
0.0%
Spring Stream
34
25
74%
3%
5
15%
2
7%
7
22%
2
5%
Valhalla Creek
11
11
95%
1%
0.2
2%
0.1
1%
0.4
3%
0.2
2%
Waynita Creek
39
27
69%
4%
6
17%
1
3%
8
20%
4
11%
West Fork Waynita Creek
17
16
95%
2%
0
2%
0.1
0.5%
0.5
3%
0.4
2%
1,107
762
69%
100%
171
15%
67
6%
238
21%
108
10%
Total
BOTHELL, WA URBAN CANOPY: APPENDIX
31
City of Bothell, WA Geographic Summary: Riparian Areas
Figure 26: Percent Urban Tree Canopy by Riparian Area
BOTHELL, WA URBAN CANOPY: APPENDIX
32
City of Bothell, WA Geographic Summary: Riparian Areas
Figure 27: Percent Possible Planting Area (Vegetation) by Riparian Area
BOTHELL, WA URBAN CANOPY: APPENDIX
33
City of Bothell, WA Geographic Summary: Parcels UTC metrics for Bothell, WA Parcels were generated in Acres and percent including Urban Tree Canopy (UTC Possible Planting Area Vegetation (PPA Vegetation), Possible Planting Area Impervious (PPA Impervious), Total Possible Planting Area (Total PPA), and Areas Unsuitable for Planting (Unsuitable). Due to the size of the dataset, tabular results were provided in GIS data format only.
Figure 28: Percent Urban Tree Canopy by Parcel BOTHELL, WA URBAN CANOPY: APPENDIX
34
City of Bothell, WA Geographic Summary: Parcels
Figure 29: Percent Possible Planting Area (Vegetation) by Parcel
BOTHELL, WA URBAN CANOPY: APPENDIX
35