URBAN STREETWATER
A comprehensive analysis of aesthetic stormwater design for urban streets
1)
CONTENT BACKGROUND Introduction Methodology Urban Ecology Urban Public Space Aesthetic Design Significance
2)
CASE STUDIES
3)
STRATEGIES
4)
MATERIALS
NE Siskiyou Street Sand River Headwaters Deaderick Street Seattle SEA Street SW 12th Avenue PSU Urban Center Plaza
Introduction Slow It Down Spread It Out Soak It In
Introduction Paving Palette Planting Palette
1 3 4 5 6 8
9 10 11 12 13 14
19 21 23 25
27 28 29
1) BACKGROUND
INTRODUCTION
As global green initiatives continue to gain support and lack of clean water becomes a more pressing issue, we can no longer afford the “out of sight out of mind” attitude we’ve maintained towards stormwater management over the past several decades. This becomes particularly apparent in urban systems where the National Academy of Sciences estimates that urban stormwater runoff is the primary source of impairment for 13 percent of rivers, 18 percent of lakes, and 32 percent of estuaries in the US. An unfortunate truth considering urban areas cover only 3 percent of the country. But how do we begin to tackle such a large infrastructure issue in urban areas where space is already at a minimum? And is it possible to manage stormwater in a way that promotes these types of sustainable practices? I believe the answer lies in the utilization of urban streetscapes. Through research, professional discussion, and a multitude of case studies, I have begun to investigate the potential of stormwater management as an amenity in urban streetscapes. 1
URBAN AESTHETIC ECOLOGY DESIGN URBAN PUBLIC SPACE
Effective stormwater design -Slow, spread, soak -ecological effectiveness -perceived value - landscape integration 2
METHODOLOGY In order to analyze the potential of urban streets for stormwater management solutions, I looked at three separate aspects of urban stormwater designs (urban ecology, urban public space, aesthetic design) and how they interacted with each other. First I researched the tenets of urban ecology and how factors like soils, water flow, and weather patterns affect and are affected by the urban landscape. Second I tried to determine the qualities of effective urban public spaces. I asked questions such as “what do people value Urban Center Plaza, Nevue Ngan Associates most in urban public space?” and “how do you make the most of limited space?”. Third I went back to the basics of aesthetics and tried to define specific characteristics of successful designs. Using these characteristics as guiding principles, I am more likely to create functional spaces that are considered amenities. Each of these areas urban ecology, urban public space, and aesthetic design contribute to the creation of a successful, artful stormwater management solution. After compiling some base knowledge, I explored the relationships between the three areas. A web of connectedness began to form as I found ways that the three areas affected and influenced one another. A concise diagram of my analysis can be found with my research conclusions on page 7 and 8. My process continued forward as I began to draw up diagrams and details for implementation strategies based on the information gathered in the research phase. I organized the information by filing the strategies under the categories of slow, spread, or soak. The strategies are not site specific or finalized but instead aim to create framework for urban stormwater management that could be applied on a project by project basis. As a culmination of my work, I plan to produce a site-specfic project that uses my research and implementation strategies as guiding principles for its design.
3
URBAN ECOLOGY Urban ecology is a relatively new field that examines the relationships of ecological functions, such as soil quality, wind, water, and wildlife patterns, in an urban environment. These natural systems are often manipulated in an urban setting in order to attain specific design or planning goals. Ignorance of the effects of these natural systems has led to some of our biggest issues in urban areas today, such as the urban heat island effect, species endangerment, and water pollution. For the purposes of this study, I focused on the issues of water in an urban setting and how these issues can be diffused using stormwater management techniques. I found successful stormwater systems needed to address five key hydrological objectives; flow rate, volume, frequency, duration, and quality. Properly implemented, green stormwater infrastructure can absorb containments, reduce runoff, and decrease amount of pollutants entering neighboring water bodies.
4
URBAN PUBLIC SPACE In an urban environment where space is at a minimum, high value is placed on urban public, or area that is shared among a variety of users. These spaces can be streets, parks, plazas and the like. For a designer, public space provides an opportunity to create an area with a variety of uses for a variety of users. Successful urban public spaces can serve a wide array of purposes. For example a successful space can improve the health and safety of a community, can increase the value of surrounding property, and can provide interesting destinations for community members and visitors alike. In this study I focused on the possibilities for urban streets as a shared space. Streets and their immediate surroundings create the connective tissue of urban system. In order to maximize the value of these areas, streets should be viewed as more that just a space for cars. Streets can be designed as an area for a variety of users by decreasing the emphasis on vehicular and adding interest and engagement for pedestrians. Streets also have an opportunity to serve ecological function by the implementation of street trees, vegetation, and green stormwater infrastructure. By viewing these necessary transportation corridors as an opportunity for improvement, designers can begin to create vibrant, functional urban public spaces. 5
AESTHETIC DESIGN Even though aesthetic design is a broad concept, it is important to understand what characteristics and details people value in order to create a space that is not only ecologically functional but aesthetically pleasing as well. Generally speaking, the goal of aesthetic design in landscape architecture is to create a ‘place’ out of ‘space’. To do this, it is important to take into consideration the area’s surroundings including plant palette, materials, character, etc. The trick is to make the space harmonious with it’s surroundings while also making it unique and original. This can be done by creating subtle material changes or adding diversity to the plant selection. In regards to stormwater management, there are a handful of goals in order make a project aesthetically pleasing. First it is vital to consider maintenance strategies at that the beginning of the design process. Because stormwater designs are dealing with the force of water, a design needs to consider how to manage sediment, runoff, infiltration, and extreme storm events. A design must also consider physical accessibility, making sure the beds are deep enough for retention but also accessible for maintenance. If the design can be aesthetically pleasing without sacrificing the functionality of the stormwater system, it can become a wonderful amenity for the community.
6
U RB A N
PU BL Streets can be more than just spaces for cars
Water collection -absorb contaminates -minimize remobilization of pollutants -minimize pollutants release into environment
Sidewalks, pathways, and trails are the connective tissue of the public realm
AC SP
UR B
AN
LOGY
IC
O EC
Streets can… Effective maintenance is a must (debris must be cleared) -treat of rainwater Goals of urban public space -add landscape -improve air quality -healthy community; decreased obesity -be effective place and chronic disease -quality Contaminant trapping -safety efficiency -convenience -steepness of slope Structural requirements of infiltration areas -interesting destinations -filter length -30cm of topsoil -encourage optional trips (stroll, play, sit, eat) -type of vegetation -hydraulic conductivity of 1 x 10^-3 ms^-1 -increase property values -adequate proportion of silt, clay, -restore habitat & organic material Effective -engage children, citizens, and decision makers -pH between 5.5 &8 stormwater design -Slow, spread, soak Things to consider -ecological PlacemakingExamples of -urban soil quality effectiveness making spaces aesthetic -light -perceived value where people want stormwater -wind - landscape to spend time management: -weather patterns integration -utilities and services -memorable qualities -swales -waste collection -have something unusual -rain gardens -have rich character -bioretention areas -reflect local community and culture
E
Stormwater Management: Hydrological objectives -flow rate -volume -frequency -duration -quality
Needs to brand a space Materials can make a design unique Create PLACE out of SPACE Street trees and effective landscaping Site specific design Create “teaching” spaces
Attributes of well-designed stormwater management: maintenance strategies information systems physical accessibility multiple use public awareness
7
N
AE S TH
ETIC
IG DES
SIGNIFICANCE: Urban ecology, urban public place, and aesthetic design are all areas that contribute to the implementation of exceptional urban streets. The first step is to make the street a destination. People visit places that have unique qualities, rich character, and tie to the local culture. Streets also have many different opportunities from a functional standpoint. They can add landscape, improve air quality, manage stormwater, or be a destination themselves. For this study, the focus was to investigate the potential of urban streets for aesthetic stormwater management. Streetscapes can utilize several different techniques for managing stormwater in an aesthetically pleasing way. For example these techniques can include bioswales, rain gardens, bioretention areas, infiltration beds, and permeable pavers. From the research phase, I was able to draw several conclusions in regards to successful stormwater designs in urban public streets. First, the movement of water must be modified. For this study I will use the phrase ‘slow, spread, soak’. Second, the system must be ecological effective. Stormwater management designs are performance-based landscapes and must have measurable value. Third the landscape also must be perceived as an amenity and given value by the local community. Lastly, the system must be smoothly integrated into its surroundings. This can be achieved through techniques such as using a local plant palette or using materials found in the community. Urban streets not only have the potential to be a powerful tool for managing stormwater runoff, but also to be a vibrant space for the community.
8
2) CASE STUDIES
NE Siskiyou Green Street
City of Portland, Bureau of Environmental Services / Portland, OR / 2003 Client:
City of Portland
Size:
590 sq ft
Project Type:
Streetscape Existing site retrofit
Design Features: Landscaped curb extensions Cost:
$20,000
Landscaped curb extensions
Description: Portland’s first residential green street. Provides an example of how curb extensions can be used to manage stormwater. Curb cuts allow water to enter beds and if the water gets high enough, excess water enters the sewer system through a drain in the back of the curb extension
Blending of materials was appreciated by the residents 9
Conclusion: Relatively inexpensive option for effectively managing stormwater. Attention should be paid to blending plant material as NE Siskiyou residents appreciated that effort.
Sand River Headwaters Green Infrastructure Woolpert, Inc & Clemson Center for Watershed Excellence / Aiken, SC / 2009 Client:
City of Aiken
Size:
Over 5 acres
Project Type:
Streetscapes Existing site retrofit
Design Features: Biorentention facility, bioswale, cistern, porous pavers, curb cuts Cost:
$3.34 mil
Use of natives on the bioswales
Description: Aiming to reduce downtown Aiken’s stormwater runoff impact on the Sand River, the green infrastructure included multiple different design features to try to contain and treat stormwater. The relatively large project aims to be low maintenance as well. Conclusion: While it may not be the most eye-catching stormwater project looked at, the project does set a good precedent for using South Carolina natives for low-maintenance.
Closer view of the swale and how it directs water
10
Deaderick Street Renovation
Hawkins Partner / Nashville, TN / 2009
Intial implementation
A few years after implementation
Client:
Metropolitan Government for Nashville Davidson County
Size:
14,200 sq ft
Project Type:
Streetscape Redevelopment project
Design Features: Biorentention facility, rain garden, porous pavers Cost: 11
$3.1 mil
Description: Primarily focused on addressing stormwater runoff and adding urban trees, the Deaderick Street renovation used cues from pedestrian crossings, intersections, previous planters to create a system that absorbs 95% of stormwater runoff in a very public area. Conclusion: Deaderick Street provides a very successful system implemented in a downtown area. Its focus on urban trees also improved it ability to retain and manage stormwater.
Seattle SEA Street
Seattle Public Utilities / Seattle, WA / 2001
Client:
City of Seattle
Size:
660 ft street block
Project Type:
Streetscape Existing site retrofit
Design Features: Bioswales
Cost:
$651,000 Bird’s eye view of the new street system
Description: Using biological mimicry, the team tries to create a street drainage system that mimics the natural landscape. They did this by reducing pervious surfaces, carefully following land contours, detaining and treating water in swales, and adding vegetation. Conclusion: An interesting take on solving the stormwater issue, mimicking the natural drainage system is a very systematic, successful way to design a stormwater system.
Landscaped roadside swales
12
SW 12th Avenue Green Street
City of Portland, Bureau of Environmental Services / Portland, OR / 2005
Client:
City of Portland
Size:
Less than 5,000 sq ft
Project Type:
Streetscapes Existing site retrofit
Design Features: Street stormwater planters
Cost:
$38,000
View of the renovated planters
13
Description: Designed as an informative example of how to retrofit urban streets for stormwater management, the SW 12th Avenue project shows how to inexpensively retrofit streets for both an aesthetic and environmental benefit. Conclusion: Seamless transition from regular to stormwater planters creates a successful, aesthetically pleasing streetscape that also is environmentally sound.
View of the planters during a rain event
PSU Urban Center Plaza Stormwater Retrofit Nevue Ngan Associates / Portland, OR / 2010 Client:
Portland State University
Size:
590 sq ft
Project Type:
Institutional Existing site retrofit
Design Features: Flow through planters
Cost:
$100,000-$500,000
Drains transitioning from one bed to the next
Description: A small portion of the SW Montgomery Green Street concept, the Urban Center Plaza retrofit integrated stormwater management concepts into existing planters and hardscape. It adds to the SW Montgomery ‘stormwater spine’ without compromising the form or function of the plaza.
The planters are both environmentally friendly and aesthetically pleasing
Conclusion: PSU Urban Center Plaza provides a good example of retrofitting planters for stormwater management function. Relatively inexpensive, the project reduces flow by 50%. 14
15
URBAN ECOLOGY
Project
Location
1. NE Siskiyou Green Street
Portland, OR
The system captured 85% of the run-off volume during a flow test for most storm systems and a minimum 60% reduction for 25-yr storm events
Since it was a residential street, attention was paid to the type of vegetation that was pre-exsisitng in the adjacent yards to ensure a seamless transition among plant material
2. Sand River Headwaters Green Infrastructure
Aiken, SC
The BMP’s were designed to capture the first inch of runoff and the finished system has close to 100% infiltration for initial runoff
Team tried to use pre-existing plant material in the design by placing and arranging native species in a way that would maximize infiltration rates
3. Deaderick Street Renovation
Nashville, TN
The street improvements are estimated to remove over 1.2 million gallons of stormwater annually which translations to approximately 95% of the stormwater for the area
This project had a focus on urban trees as well, so in addition to wettolerant shrubs and perennials, a series of street trees were introduced to the streetscape
Percentage of stormwater managed
Plant material used
URBAN PUBLIC SPACE
AESTHETIC DESIGN
Design cues are taken from
How does the design respond to space allowed
Types of material
Community reaction
Again, design was meant to easily transition from yard to streetscape and be visually read as an ‘extension’ to the existing landscaping
Extension’s dimensions act as a traffic calming device while still allowing two lanes of traffic and the extensions are placed at the end of the street with a 2% slope in order to collect the maximum amount of water
Materials were very basic for this project; curbs were cement to match with existing curbs and plant material consisted of small shrubs and perennials on a bed of soil and small river rocks
House values on NE Siskiyou Street have risen in response to the extensions and hundreds of residents have signed onto a list to have curb extensions added to their neighborhood street
Project was constructed in preexsisting parkway medians; care was taken to preserve existing trees and other existing infrastructure
The city did not purchase any additional land for the project, so existing land had to be maximized and re-graded in order to create a viable water flow
Mass planting and subtle grading changes are the key to this largescale project; less attention was paid to material detailing due to the expansiveness of the project
Due to the subtleness of the changes, this progressive project was well received by a relatively conservative community
Being in one of the most public areas of the city, design had to be geared towards the pedestrian and measures were even taken to provide infrastructure support for street festivals
Being a streetscape, space is limited for stormwater management, therefore each planter is used for water intake and permeable pavers are used when possible
Materials are in tune with the public buildings that surround the street and extra infrastructure such as streetlights are modern and add to the ambiance of the space
Extremely wellreceived and visible to the public, Deaderick street has become the catalyst for more stormwater projects throughout the city
16
17
URBAN ECOLOGY
Project
Location
4. Seattle SEA Street
Seattle, WA
During the first two years of operation the system was monitored and determined to reduce runoff by 9% and slower water velocities by approximately 20%
Existing vegetation and large trees were relocated to fit homeowners needs and then bioswales were planted with native wetland and upland plant species
5. SW 12th Ave Green Street
Portland, OR
Retaining almost 100% of runoff for 2-yr storm events and less and around 70% for 25-yr event, these planters are a very successful implementation for streetscapes
Planters are densely planted with Juncus patens and a Nyssa sylvatica tree, and then Nadina and Lirope are in adjacent planters for seasonal interest and diversity
6. PSU Urban Center Plaza Stormwater Retrofit
Portland, WA
Underground structures prohibit infiltration, so the flow-through planters utilized are only able to reduce runoff by 50%
Previously void of any plant material, the plaza now has a balanced mix of plant material (lots of lirope) and hardscape
Percentage of stormwater managed
Plant material used
URBAN PUBLIC SPACE
AESTHETIC DESIGN
Design cues are taken from
How does the design respond to space allowed
Types of material
Community Reaction
The street was redirected to follow natural curves and help direct stormwater runoff into the bioswales; overall the system is supposed mimic a natural system
The slope and structure of the street determine the design of the stormwater system; this helps maximize the efficiency and ability of the system to reduce runoff
Sidewalks are repaved with porous material and the landscape is designed with natural elements such as rocks and plants to mimic a natural system
The neighborhood as a new ‘sense of place’ as a result of the street project; it has also increased the environmental awareness of the surrounding community
The space is enhanced by adding attractive greenspace in an urban area and by paying close attention to small details like drain covers and paving styles
Space is limited in the streetscape so planters are designed to be as deep as possible while still being aesthetically pleasing and nonhazardous
Porous pavers and unique detailing adds to the appeal of the design; plant texture also create an interesting palette
One of the first projects of its kind, the SW 12th Ave project started a series of similar projects across not only Portland but other urban areas across the country
As part of the ‘green spine’ of the SW Montgomery Green Street Concept plan, the PSU plaza creates a connection to the plan while also staying with the character of the school
The plaza had lots of space for change, but the design had to respond to pedestrian use, water treatment, and aesthetic appeal
An appealing mix of pavers and granite contrasts well with the moving water to create interest in the plaza
The plaza has seen an increase in usage since the renovation both by students and the public; it has also made stormwater management a public amenity
18
3)
STRATEGIES INTRODUCTION In order to create a successful stormwater management system, special attention must be paid to the local conditions of the project. Factors such as soil type and quality, average rainfall during storm events, slope, and vegetation type all make a difference in the design necessary to create a effective system. That being said , there are several overarching implementation strategies that can be used and modified for most aesthetic stormwater projects. For the purposes of this study I will focus on strategies that are applicable to urban streetscapes. The strategies have been organized into the three categories, slow , spread, and soak, and example dimensions have been provided. Dimensions can be modified in response to site specific conditions. A material palette has also been including for suggestions for plants and hardscape materials. However the plant palette is specific to the southeast US due to the location of the study.
19
SLOW IT DOWN SPREAD IT OUT SOAK IT IN 20
SLOW it down Strategies: -Retention areas
Providing areas for water gather temporarily will reduce the amount of pollutants gathered and deposited into local water sources
-Curves
By mimicking natural curves in roads and landscaped areas, a designer can reduce the speed of running water and thus less its negative impact
-Texture Like curves, texture in paving or landscaping causes a disturbance in the direct path of running water and therefore slows it down
21
EXAMPLE: Retention Area
concrete base
pipe to existing stormwater infrastructure
gravel/peastone bed used to trap contaminants
22
SPREAD it out Strategies: -Flow-through planters
Water can be cleaned by a series of flow through planters if stormwater infrastructure is needed in an area with a lot of impervious surfaces
23
-Filtration beds
-Curb details
Filtration beds are a good alternative if water can not be directly introduced into the water table; water can be cleaned by filtration beds before entering the stormwater pipes Subtle curb details can change what was a concrete wall into a stormwater planter entrance for water flow
EXAMPLE: Curb Details Curb cut The simplest option, a series of curb cuts allows water to move off the road and into the stormwater planter.
Perforated curb In order to utilize a stormwater planter but still give the illusion of an interrupted curb, a perforated curb may be used.
Flush curb A flush curb utilizes road slope to send runoff into the planting bed. This type of curb should not be used on high-speed roads. 24
SOAK it in Strategies: -Infiltration beds Infiltration beds allow water to be absorbed on site through stormwater planters; plants and trees aid with water absorption
-Permeable pavers Permeable pavers reduce water flow by allowing a percentage of rain/runoff to flow between the pavers and into the ground
25
EXAMPLE: Permeable Pavers permeable pavers (see materials)
plant material (see materials)
aggregate base
mulch layer 2� amended soil 12-36� (depending on plant selection)
open graded base
distribution pipe into planter (optional)
filter fabric
crushed gravel
26
4)
MATERIALS INTRODUCTION Materials can enhance projects and add character to a space. In aesthetic stormwater management projects it is important to choose materials that are both aesthetically pleasing as well as functional. Hardscaping and softscaping options are available for streetscapes that reduce the flow of stormwater into unsustainable underground pipes. Through research and case study analysis a list of potential materials for functional stormwater streetscapes has been compiled. The following material palettes suggest potential hardscape materials and plants for stormwater projects. However, it should be noted that the plant palette is specific to the southeast US due to the location of the study.
27
PAVING PALETTE
Pervious Asphalt
Pervious Concrete
Interlocking Concrete Pavers
Brick Pavers
Gravel
28
PLANT PALETTE Street Trees
29
Fraxinus pennsylvanica
Liquidambar styraciflua
‘Green Ash’
‘American Sweetgum’
Diospyros virginiana
Acer rubrum
‘Common Persimmon’
‘Red Maple’
Shrubs
Itea virginica
Carex stricta
Ilex decidua
‘Virginia Sweetspire’
‘Tussock Sedge’
‘Possumhaw’
Clethra alnifolia
Ilex glabra
Lindera sp.
‘Summer Sweet Clethra’
‘Inkberry’
‘Spicebush’
Cornus sericea ‘Redtwig Dogwood’
Cephalanthus occidentalis ‘Buttonbush’ 30
Perennials
31
Andropogon gerardii
Asclepias incarnata
Aquilegia canadensis
‘Virginia Sweetspire’
‘Swamp Milkweed’
‘Columbine’
Aster novae-angliae
Iris sp
Lobelia cardinalis
‘New England Aster’
‘Iris’
‘Cardinal Flower’
Hibiscus coccineus
Helianthus angustifolius
Lobelia siphilitica
‘Scarlet Swamp Hibiscus’
‘Swamp Sunflower’
‘Blue Cardinal Flower’
Lysimachia clethroides
Lysimacha punctata
‘Gooseneck Loosestrife’
‘Yellow Loosestrife’
32
REFERENCES INFORMATION
Bain, Lesley; Gray, Barbara; Rodgers, Dave. (2012). Living Streets. Wiley. Retrieved 24 February 2013, from <http://lib.myilibrary.com?ID=362036> Breuste, J., Feldmann, H., & Ohlmann, O. (1998). Urban ecology. Berlin: Springer-Verlag. Denman, L. (2006). Are street trees and their soils an effective stormwater treatment measure? Seventh National Street Tree Symposium, University of Adelaide, Australia. Dreiseitl, H. (Ed.), Grau D., & Ludwig, K.H.C. (2001). Water- scapes: Planning, building and designing with water. (M. Robin- son, Trans.). Berlin: Birkh채user. Echols, S. 2007. Artful rainwater design in the urban landscape. Journal of Green Building 2(4):1-17 Fay Jones School of Architecture. (2010). LID: a design manual for urban areas. UACDC, Fayetteville, Arkansas The National Academy of Sciences. (2008). Retrieved from http://dels.nas. edu/resources/static-assets/materials-based-on-reports/reports-in-brief/ stormwater_discharge_final.pdf ASLA. (2013) Stormwater Case Studies. Retrieved from http://www.asla. org/stormwatercasestudies.aspx
PHOTOS Urban public space: http://www.nyhabitat.com/blog/wp-content/uploads/2013/01/Timessquare-manhattan-new-york-nyc-crossroads-world.jpg Urban Ecology: http://upload.wikimedia.org/wikipedia/commons/5/57/Seattle_Waterfront_ from_Bell_Street_Pier.jpg http://www.minneapolisparks.org/graphics/caring/forest/urban_forest_1.jpg Aesthetic design: http://2.bp.blogspot.com/_fY54okBt12U/S3Mx5VWXkWI/AAAAAAAABfU/ oOiuEnZsU8o/s1600-h/pastel+palette.jpg http://gardendrum.com/wp-content/uploads/2013/01/Gabion-cages-withvarious-fill-materials.jpg http://lassenmaterial.com/images/product-shot.jpg Case Studies: http://www.asla.org/stormwatercasestudies.aspx http://www.portlandonline.com/shared/cfm/image.cfm?id=124848 http://nevuengan.com/sites/nevuengan.com/files/imagecache/project/ project/16_0009_5-Urban%20Plaza.jpg http://www.woolpert.com/ http://content.mindmixer.com/Live/Projects/metroofnashville/content/88802/MedResDownload_Deaderick%20Street-001_IdeaImagePhotoDetail.png?635056334735670000 http://www.djc.com/stories/images/20090105/bioswale_big.jpg
PHOTOS (cont.) Materials: Plants http://lve-baumschule.de/i/pflanzen/Liquidambar-styraciflua__8907.jpg http://extension.missouri.edu/p/G6800-10 http://oregonstate.edu/dept/ldplants/images/ilglabs53.jpg http://www.wildflower.org/plants/result.php?id_plant=DIVI5 http://plantplaces.com/photos/Cephalanthus.occidentalis.Moonlight. Fantasy(Small).JPG http://newfs.s3.amazonaws.com/taxon-images-1000s1000/Clethraceae/clethra-alnifolia-ha-bpatterson.jpg http://static.wixstatic.com/media/e44642_00dcd850eadde2955ae52eaaeb ea4306.jpg_srz_2816_2112_85_22_0.50_1.20_0.00_jpg_srz http://aggie-horticulture.tamu.edu/newsletters/hortupdate/2009/Nov09/Deciduous.jpg http://www.provenwinners.com/sites/provenwinners.com/files/imagecache/ max_width/ifa_upload/cc04070.jpg http://blogs.scottarboretum.org/gardenseeds/wp-content/uploads/2008/11/ lindera-glauca-var-salicifolia-1.jpg http://upload.wikimedia.org/wikipedia/commons/a/ae/Carex_stricta.jpg http://www.calfloranursery.com/sites/default/files/imagecache/product_ full/helianthus_angustifolius.jpg http://plants.landsburgnursery.com/Content/Images/Photos/F269-07.jpg
Materials: Pervious Paving http://chesapeakestormwater.net/wp-content/uploads/2012/01/Porous-Concrete-Driveway.jpg http://www.pinehallbrick.com/uploads/Stormpave(3).jpeg http://www.greatbaystewards.org/images/GBDC/PorousAsph_Gravel.gif http://www.kingpaversli.com/images/concrete_pavers.jpg http://www.mayang.com/textures/Stone/images/Aggregate%20Stone/fine_ gravel_ashphalt_roof_4012151.JPG
ALLY HANGARTNER | 678.920.1225 | AHANGAR@CLEMSON.EDU