x>EPA
United States
Environmental Protection
Agency
2014 GREEN INFRASTRUCTURE TECHNICAL ASSISTANCE PROGRAM
City of Clarkesville
Clarkesville, GA
Clarkesville Green Infrastructure
Implementation Strategy
Photo: Justin Ellis
April 2015
EPA 832-R-15-005
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About the Green Infrastructure Technical Assistance Program
Stormwater runoff is a major cause of water pollution in urban areas. When rain falls in undeveloped
areas, soil and plants absorb and filter the water. When rain falls on our roofs, streets, and parking lots,
however, the water cannot soak into the ground. In most urban areas, stormwater is drained through
engineered collection systems and discharged into nearby water bodies. The stormwater carries trash,
bacteria, heavy metals, and other pollutants from the urban landscape, polluting the receiving waters.
Higher flows also can cause erosion and flooding in urban streams, damaging habitat, property, and
infrastructure.
Green infrastructure uses vegetation, soils, and natural processes to manage water and create healthier
urban environments. At the scale of a city or county, green infrastructure refers to the patchwork of
natural areas that provides habitat, flood protection, cleaner air, and cleaner water. At the scale of a
neighborhood or site, green infrastructure refers to stormwater management systems that mimic
nature by soaking up and storing water. Green infrastructure can be a cost-effective approach for
improving water quality and helping communities stretch their infrastructure investments further by
providing multiple environmental, economic, and community benefits. This multi-benefit approach
creates sustainable and resilient water infrastructure that supports and revitalizes urban communities.
The U.S. Environmental Protection Agency (EPA) encourages communities to use green infrastructure to
help manage stormwater runoff, reduce sewer overflows, and improve water quality. EPA recognizes
the value of working collaboratively with communities to support broader adoption of green
infrastructure approaches. Technical assistance is a key component to accelerating the implementation
of green infrastructure across the nation and aligns with EPA's commitment to provide community
focused outreach and support in the President's Priority Agenda Enhancing the Climate Resilience of
America's Natural Resources. Creating more resilient systems will become increasingly important in the
face of climate change. As more intense weather events or dwindling water supplies stress the
performance of the nation's water infrastructure, green infrastructure offers an approach to increase
resiliency and adaptability.
For more information, v\s\t http://www.epa.Qov/Qreeninfrastructure
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Acknowledgements
Jamie Piziali, USEPA
Christopher Kloss, USEPA
Jeremy Pirkle, City of Clarkesville
Tim Durham, City of Clarkesville
Justin Ellis, Soque River Watershed Association
Duncan Hughes, Soque River Watershed Association
Heather Fisher, Tetra Tech, Inc.
Eric Byrne, Tetra Tech, Inc.
Martina Frey, Tetra Tech, Inc.
Jason Wright, Tetra Tech, Inc.
Alex Porteous, Tetra Tech, Inc.
Hillary Nicholas, Tetra Tech, Inc.
Maureen Harris, Tetra Tech, Inc.
This report was developed under USEPA Contract No. EP-C-11-009 as part of the 2014 USEPA Green
Infrastructure Technical Assistance Program.
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Contents
1 Executive Summary 1
2 Introduction 3
2.1 Demographic Information 4
2.2 Local Development Goals/Local Planning Documents 5
2.3 Local Water Quality/Quantity Issues and Goals 5
3 Potential Site Identification and Prioritization 8
3.1 Prioritization Results 8
3.2 Initial Parcel Screening Results 13
3.3 Recommendations for Priority Sites 14
4 Code and Ordinance Review 15
5 Potential Funding Sources 17
5.1 Funding Related to Water Resources 17
5.2 Funding Related to Landscaping 18
5.3 Funding Related to Energy Efficiency 19
5.4 Funding Related to Economic Development 19
5.5 Stormwater Utility Funding 20
5.6 Recommended Funding Approach 21
6 Strategy Summary 23
7 References 25
Appendix A: Parcel Prioritization Detailed Methods and Results A-l
Appendix B: Compendium of Indicators for Prioritizing Green Infrastructure Opportunities B-l
Appendix C: Design Recommendations C-l
Appendix D: Code Review Checklist D-l
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Figures
Figure 2-1. Curbless bioswale at the recently constructed Habersham County Judicial Center 4
Figure 2-2. Soque River past and current 303(d)-listed segments in the vicinity of Clarkesville 7
Figure 3-1. Clarkesville parcel prioritization results 10
Figure 3-2. Clarkesville parcel prioritization results, close-up of priority parcels 11
Tables
Table 3-1. Prioritization Results 12
Table 3-2. Initial Screening Results 13
Table 3-3. Preliminary, Planning-Level Cost Estimates for Select Priority Projects 15
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I Executive Summary
The City of Clarkesville is a small, fast-growing community interested in developing a green
infrastructure plan. The city's municipal separate storm sewer system is not subject to state or federal
requirements to address stormwater pollution. The city has proactively addressed stormwater quality
and quantity through post-construction stormwater requirements and supporting the use of green
infrastructure for stormwater management.
EPA worked with the city to develop the Clarkesville Green Infrastructure Implementation Strategy,
which provides the basic building blocks for a green infrastructure plan: 1) goals and objectives, based
on the city's current and future needs, 2) a comprehensive prioritization of parcels throughout the city
to identify opportunities for further evaluation (Appendices A and B), and 3) site-specific design
recommendations (Appendix C), including illustrations and descriptions of potential green infrastructure
practices. A range of green infrastructure practices are recommended, including rainwater harvesting, a
green alley, bioretention, permeable pavement, a green roof, stormwater wetlands, and stormwater
detention.
USEPA used Tetra Tech's Green Infrastructure Opportunity Checklist Tool (Appendix D) to identify
opportunities for improving the City of Clarkesville's Zoning Ordinance to encourage implementation of
green infrastructure by developers, property owners, and other parties. The following key opportunities
were identified:
1. Street and Parking Dimensions: Allow narrower street and travel lanes with curb pullouts for
passing of large vehicles. More specifically, allow travel lanes of 10 to 12 feet or less; in
residential developments, allow street pavement widths of 18 to 22 feet. For parking, allow a
smaller minimum stall area so that at least some stalls can be 9 feet by 15 feet or smaller. While
not specifically prohibited, encouragement or incentives for curb bumpouts/extensions could be
included in city policies or programs.
2. Redevelopment: Include incentives for redevelopment through minor relaxation of site design
standards (i.e. stormwater retention) or other requirements. The undisturbed land (i.e.
greenfield) that might have been developed without the incentives would then continue to
provide stormwater management benefits. The City of Clarkesville might consider specific areas
for incentives, like the downtown, or have the incentives apply to redevelopment throughout
the city.
3. Setbacks: Reduce required setbacks to encourage clustering and open space design. Minimum
lot setbacks could be reduced to 20 feet in the front, 25 feet in the rear, and 8 feet on either
side for higher density residential development (1/2-acre lot or less in size). Further reductions
in setbacks beyond these recommendations could also be considered. At a minimum, these
reduced setbacks could be used as guidance for approving conservation subdivisions. The city
may also want to consider reducing setbacks for the more urban residential zoning districts like
R-1A, R-1B, and R-2.
4. Phased Disturbance of Vegetated Areas: In site plans, require that disturbance of vegetated
areas be phased to reduce erosion of topsoil.
5. Wetlands: Require that all development minimize hydrologic alteration to existing wetlands.
6. Stream Buffers: Increase the width of required stream buffers or extend stream buffer
requirements so that all development must preserve at least a 50-foot buffer.
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7. Best Management Practice (BMP) Maintenance: Require a BMP maintenance plan for all
stormwater facilities.
8. Performance Standards: Develop additional stormwater performance standards for new
development and redevelopment, including standards for stormwater volume, water quality
treatment, and channel protection.
Funding sources were reviewed, and leveraging amongst diverse sources was considered in relation to
the city's interests and site-specific opportunities. The following funding approach is recommended:
• Continue to pursue WaterFirst Community designation.
• Investigate feasibility and public interest in a stormwater utility for use in funding projects and
grant cost share.
• Collaborate with affordable housing and economic development programs to find opportunities
for green infrastructure and leveraging with Appalachian Regional Commission (ARC) Grants,
U.S. Economic Development Administration (USEDA) Economic Development Assistance
Programs, and the Community Development Block Grant (CDBG) program.
• Pursue site-specific funding related to water resources, landscaping, energy efficiency,
affordable housing, and economic development.
The overall recommended strategy for the City of Clarkesville is summarized in a 6-step process:
1. Investigate property owner interest, cost and general feasibility of site-specific opportunities
and select a sub-set to pursue more detailed conceptual designs.
2. Include consideration of key opportunities for code improvement in future zoning code
revisions.
3. Continue to pursue WaterFirst Community Designation.
4. Investigate feasibility and public interest in a stormwater utility for use in funding projects and
grant cost share.
5. Collaborate with affordable housing and economic development programs to find opportunities
for green infrastructure and leveraging with ARC Grants, USEDA Economic Development
Assistance Programs, and the CDBG program.
6. Pursue site-specific funding for Appendix C Exhibits 1-11 as appropriate based on further
planning and evaluation.
This approach should evolve over time based on changing needs and as new opportunities for
partnership and funding emerge. With these basic steps, the City of Clarkesville can continue to build
their experience with green infrastructure and realize the multiple benefits of green infrastructure
including but not limited to water quality improvement, flood prevention, beautification, and
community development.
Clarkesville's recent growth and redevelopment present stormwater management challenges. As a small
city, its staff has been proactive about partnering with public and private entities and finding creative
solutions to urban stormwater issues. Their efforts, exemplified by this strategy, are helping to address
stormwater challenges and prevent larger problems in the future. By outlining goals, priorities, code
improvements, project opportunities, and funding sources, the City of Clarkesville's strategy provides a
model approach for small, unregulated communities to successfully pursue green infrastructure.
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2 Introduction
The City of Clarkesville represents an engaged, close-knit community of residents whose daily lives and
recreation depend on its natural resources and downstream water quality. With a downtown square
and historic district that draw crowds throughout the year, this city prides itself on its community
character. The city's policies and practices express a value for green space, whether it is defined as
urban landscaping, mature trees, parks, or natural areas.
The city's Public Works staff is familiar with green infrastructure concepts and has been working to
incorporate them into a variety of projects. Clarkesville's recent green infrastructure efforts include the
development of greenways and parks with preserved open space. The city's Greenway Master Plan
connects parks to the downtown business district, and future trails are planned to provide a loop around
the entire city. The city's zoning code encourages conservation design in new developments and the use
of native vegetation in developed landscaping. The City of Clarkesville partnered with Habersham
County, the Soque River Watershed Association (SRWA), and North Georgia Technical College in the
design of a pocket wetland, grass swale, and two bioswales for the recently constructed Habersham
County Judicial Center (Figure 2-1). The city also played a role in encouraging the retrofit of a
bioretention cell on private property near downtown.
Considering the city staff's familiarity and recent experience with green infrastructure, this strategy
provides recommended next steps to help strengthen the city's current pursuits and minimize both
financial and regulatory barriers to implementing green infrastructure. Potential parcel-scale
opportunities are prioritized based on the city's green infrastructure goals as well as key geospatial data.
The priority sites are evaluated, and design recommendations are provided for 11 of the most promising
sites. To address policy barriers, the strategy recommends changes and additions to the city's Zoning
Ordinance that will help encourage the use of green infrastructure in future development. Finally,
funding opportunities are identified to support a variety of green infrastructure pursuits and
partnerships.
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Figure 2-1. Curbless bioswale at the recently constructed Habersham County Judicial Center
(Source: Justin Ellis)
2.1 Demographic Information
Clarkesville is a small city with a population of 1,742 located in the Southern Inner Piedmont eco-region
of northeast Georgia and is the county seat of Habersham County (City of Clarkesville, 2013). According
to the U.S. Census Bureau, the city has a total land area of 1.9 square miles compared to Habersham
County, which is 276 square miles (U.S. Census Bureau, 2014). It is approximately 90 miles northeast of
Atlanta. The population of Clarkesville has grown by 39 percent since the 2000 census. The median age
of residents is 38.9 years. Fifty-three percent of residents are female (City of Clarkesville, 2013). The
largest Clarkesville ethnic groups are white (82.9%) followed by black (7.8%) and Hispanic (5.5%)
(CensusViewer, 2012).
The median household income in Clarkesville is about $30,000 compared to about $47,000 for the State
of Georgia, and nearly 19 percent of Clarkesville residents live in poverty. The predominant industries
are accommodation and food services, manufacturing, and retail trade (CensusViewer, 2012; City-
Data.com, 2013).
Agriculture is the top industry in Habersham County. The main crops are peaches and apples and the
main industries are poultry and beef. Tourism continues to be an important part of the county's
economic development and growth. The county is also experiencing a steady growth in retirees
(Habersham County, 2014).
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Clarkesville is designated as a "Better Hometown" by the Georgia Department of Community Affairs.
Clarkesville receives assistance to develop commercial areas through historic preservation efforts and
downtown revitalization projects (Georgia Department of Community Affairs, 2014).
Several City of Clarkesville planning documents relate directly to the community benefits provided by
green infrastructure. The city' s Zoning Ordinance contains the following sections that seek to protect
open areas, preserve natural features, and provide community green space:
• Preservation corridor overlay district.
• Subdivision requirements related to open space.
• Conservation subdivision design option.
• Tree preservation ordinance.
Through the Clarkesville Greenways Plan, the city developed a map that shows existing and planned
greenways and trails connected to the downtown area. The city is also interested in streetscape
improvement projects throughout its downtown area and has already completed one streetscape
project. Greenways and streetscaping provide valuable and cost-effective opportunities for green
infrastructure. Combining those projects with green infrastructure could not only reduce development
costs for both efforts, but also increase the overall environmental, social, and economic benefits
provided. When street trees are implemented as part of a streetscape project, tree boxes can be
designed to treat and infiltrate stormwater. Bioretention cells can be located along greenways to
protect streams from stormwater impacts, provide additional aesthetic enjoyment of the trail, and
promote establishment of native plant species, among other benefits.
Community development projects often provide opportunities for leveraging funding and using green
infrastructure to achieve economic and social benefits along with water quality and quantity benefits.
Affordable housing is an example of a development project than can incorporate green infrastructure
into its design and be at least partially funded by the larger development funding source (e.g.,
Community Development Block Grant). The City of Clarkesville has expressed an interest in innovative
funding opportunities, which can include, but are not limited to, affordable housing developments.
Based on these plans and general public interest, the City of Clarkesville proposed several goals as part
of their request for technical assistance. The city and EPA discussed these goals and, adding a few
additional details, established the following planning goals for green infrastructure:
• Incorporate green infrastructure into parks.
• Integrate green infrastructure planning with streetscape, greenway, and other city plans.
• Identify opportunities that are eligible for innovative sources of funding.
The strategy considers these goals and prioritizes sites based on whether they provide opportunities for
implementing the city's existing plans as well as social and economic benefits to the community.
Green infrastructure provides solutions for addressing the city's stormwater management goals and
protecting its water resources, particularly the Soque River and its tributaries. Valued as a river of both
local and regional significance, the Soque River provides drinking water for the city and is a tributary of
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the Chattahoochee River, the primary drinking water supply for millions of downstream residents.
Popular recreational activities within and along the river include fishing, paddling, and hiking. The River
receives treated effluent from the city's wastewater treatment plant and stormwater runoff from urban
areas within Clarkesville's jurisdiction.
Georgia Environmental Protection Division (GAEPD) listed a 29-mile reach of the Soque River on the
2014 draft 303(d) list of impaired waters, as impaired for impacts to the river's biological communities,
particularly fish, due to nonpoint sources or other unknown sources (Figure 2-2; GAEPD, 2014). This
portion includes the Soque River in Clarkesville upstream of SR 17. The river downstream of SR 17 is
currently listed as supporting designated uses in GAEPD's 2014 draft assessment. The Soque River within
Clarkesville was previously listed as impaired due to fecal coliform and has been delisted as of the draft
2014 303(d) list. Clarkesville continues to manage stormwater with a focus on fecal coliform to further
protect the river.
The City of Clarkesville is an active member of the Soque River Watershed Partnership (SRWP). In 2007,
SRWP completed the Soque River Watershed Protection Plan (WPP), which was based on the USEPA's
Nine Key Elements of Watershed Planning. The WWP identifies pollutant sources and causes and
outlines a strategy to achieve pollutant load reductions that would meet water quality standards and
support fish and other aquatic life. SRWP has received and implemented several grants and
accomplished many of the actions outlined in the WPP. Green infrastructure would provide further
opportunities to achieve progress on the WPP goals for improving and protecting water quality and
aquatic habitat.
The city has a municipal separate storm sewer system that is not subject to state or federal
requirements to address stormwater pollution. The city has been proactive in its control of stormwater
quality and quantity through local requirements, and the subdivision section of the Clarkesville Zoning
Ordinance requires that a stormwater management plan be prepared for new development or
redevelopment of any site that involves:
• New development in which 5,000 square feet or more of new impervious area is created or land
disturbing activity of one acre of land or more occurs.
• Redevelopment site on which more than 50 percent of the site is redeveloped or increases the
impervious area on site by more than 5,000 square feet.
• Any commercial or industrial development. (All commercial and industrial developments must
have at least one stormwater management facility.)
Stormwater facilities are required to:
• Be designed so that peak release rates (when combined with all detention bypass areas) are
equal to or less than the predeveloped runoff rates at the same location.
• Control the 2- to 50-year storm events.
• Provide the safe passage of the 100-year storm event while providing one foot of free board
between the 100-year pond elevation and the top of the dam.
The identification of green infrastructure opportunities for this project focuses on existing development
within the city, paying particular attention to opportunities in Clarkesville's highly impervious downtown
district. Retrofits involving green infrastructure would need to be designed to meet the city's
stormwater requirements. Green infrastructure, by definition, involves techniques that seek to mimic
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the predevelopment hydrograph. Green infrastructure designs provide an opportunity for the city to
manage stormwater not only on new development, but development built prior to the enactment of its
stormwater requirements.
\ Segment ofsoque River listed as impaired
in draft 2014 303(d) list for biological communities
Segment ofSoque River listed as impaired
in 2012 303(d) list for fecal coliform,
currently not listed as impaired in draft 2014 list
Clarkesville: 303(0) Listed Segments
0 0.15 03
TETRA TECH
Figure 2-2. Soque River past and current 303(d)-listed segments in the vicinity of Clarkesville
Based on its commitment to protecting the Soque River and addressing stormwater runoff from urban
areas, the city has established the following green infrastructure goals relating to water quality and
stormwater management:
• Address water quality impairments in the Soque River.
• Address additional threats to water quality from existing and future increases in stormwater
runoff.
The identification of green infrastructure opportunities was focused on prioritizing parcels and providing
recommendations that would best meet the city's water quality and stormwater management goals.
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3 Potential Site Identification and Prioritization
The city's goals formed the basis for prioritizing parcels and screening for urban green infrastructure
retrofit opportunities. The selection of site-specific opportunities was based on a comprehensive
prioritization using remote spatial data followed by an on-site review of opportunities and constraints.
Recommended parcels were identified using the following process:
1. Select parcels within municipal boundaries and within a 100-meter buffer outside of municipal
boundaries.
2. Rank parcels based on the following indicators using a scale from 1 (worst opportunity) to 10
(best opportunity):
a. Publicly Owned Parcels
b. Impervious Surfaces
c. Parcel Size
d. Located in a Priority Watershed
e. Infiltration Capacity
f. Located in a Priority Characterization Area
g. Proximity to Maintenance Need
h. Proximity to Stormwater Structural Damage
i. Proximity to Stormwater Inlet, Catchment Basin, or Conveyance Structure
j. Percent Slope
3. Calculate a composite score based on the rankings (i.e., sum of scores divided by number of
indicators; highest score indicates best opportunity).
4. Review the 10 highest scoring parcels for green infrastructure opportunities and screen parcels
for site-level constraints.
5. Draft recommendations for green infrastructure opportunities on the ten highest ranked
parcels.
Appendix A provides detailed definitions of the indicators and outlines the methods that were used to
score the parcels. Each parcel received a score for each indicator, and the scores were compiled into a
normalized, composite score reflecting all of the indicators.
Throughout the prioritization and screening process, the city's input and priorities provided key
guidance into how the parcels were scored and which parcels were included on the priority list. The
prioritization was designed as a tool to facilitate the city's site identification and decision-making
process.
! I
A total of 1,265 parcels meet the first selection criterion of being located within municipal boundaries or
within a 100-meter buffer outside these boundaries. Figure 3-1 shows the location of the 10 highest
scoring parcels (priority parcels) along with the lower scoring parcels, and Figure 3-2 provides a close-up
of the priority parcels. Many of highest scoring parcels are located downtown, and the remaining parcels
are located relatively near the downtown area.
Table 3-1 compares the scores of the 10 highest scoring parcels; 9 out of 10 are public properties or are
located in a priority watershed, or both. Most of these parcels fall within the two higher categories of
imperviousness and size. For all of these parcels, the majority of their land area is classified with
hydrologic soil group (HSG) B soils, which represents moderately deep, moderately well-drained soils
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that should be suitable for infiltration. All of the 10 highest scoring parcels fall within at least one of the
priority characterization areas, including parcels near existing or planned parks and/or future planned
streetscaping. All of the parcels are within 200 feet of a previously identified stormwater maintenance
need and a stormwater catchment/conveyance, and all but one are also within 200 feet of previously
documented stormwater structural damage. Most parcels have slopes less than 10 percent; those that
have higher slopes required further evaluation in the field.
One initial consideration was the lack of parcels with HSG A (high infiltration) soils in the priority parcels.
This is an expected result because outside of the Coastal Plain, HSG A soils are not common and typically
occur within alluvial floodplains.
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Legend
Parcel Ranking
^H 2.25 -4.15
4.16-5.55
| 5.56-7.84
H 7.85 - 8.5 (Top 10 Priority Parcels)
*&* Soque River
j^BJSweetgum Creek Watershed
TRocky Branch Watershed
^] City Limits
Clarkesville Parcel Prioritization Results
NAD_1983_Sta!ePlane_Georgia_West_FIPS_1002_Feet
Map Produced 10-15-2014
0 0.125 0.25
0 0.3 0-6
0.5
3 Miles
1.2
=1 Kilometers
TETRA TECH
Figure 3-1. Clarkesville parcel prioritization results
10
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Clarkesville Parcel Prioritization Results
NAD 19B3_StatePlane_Georg,a_West_FiPS_1002_Feel
Map Produced 10-15-2014
N 0 0.045 0,09 0.18
AO 0.1 0.2 0.4
^ —i Kilometers
2.25-4,15
4.16-5,55
5.56 - 7.64
7.85 - 8.5 (Top 10 Priority Parcels)
S
?"*JSweetgum Creek Watershed
I Rocky Branch Watershed
T^ TETRATECH
Figure 3-2. Clarkesville parcel prioritization results, close-up of priority parcels
II
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Table 3-1. Prioritization Results
Parcel
Code
102 093
069 032
069A009
104 339
102 086
102 087
069 043
102 017
104 041
104 024
Publicly
Owned
Parcels
10
10
10
10
10
10
10
10
10
Impervious
Surface
7.5
10
7.5
7.5
7.5
2.5
7.5
Parcel Size
7.5
7.5
10
10
7.5
7.5
7.5
10
10
10
Priority
Hydrologic
Watershed Soil Groups
10
10
10
10
10
10
10
10
7.5
7.5
7.5
7.5
7.5
7.5
7.5
7.5
7.5
7.5
Priority
Charact.
Area
7.5
7.5
7.5
Maint.
Need
10
10
10
10
10
10
10
10
10
10
Struct.
Damage
10
10
10
10
10
10
10
10
10
Sw.
Catch/
Conv.
10
10
10
10
10
10
10
10
10
10
% Composite
Slope Score
10
10
7.5
2.5
7.5
10
2.5
7.5
10
8.8
8.4
8.3
8.1
8.0
7.9
7.9
12
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3.2 Initial Parcel Screening Results
The 10 highest scoring parcels were reviewed with a geographic information system (GIS) overlay of
water and sewer lines to provide an initial screening of potential conflicts for green infrastructure. Table
3-2 presents the results of the initial screening. The parcels appeared to present either minor or no
conflicts with water and sewer lines. The field investigation allowed for additional evaluation of utility
conflicts, including power and gas lines, as well as a more comprehensive investigation of the priority
parcels.
Table 3-2. Initial Screening Results
Parcel #
102 093
069 032
069A009
104 339
102 086
102 087
069 043
102 017
104 041
104 024
Assessment
• Water lines along northeast and northwest portions of parcel.
• Minimal conflict anticipated.
• Sewer along Northwest and Southwest borders
• Stormwater pipes, ditches, and creeks located in western corner
• Minimal conflict anticipated
• Stormwater lines along western half of parcel
• Largest green space is the town square in the middle of downtown
• No utility conflicts anticipated
• Water and Sewer along South and West borders
• Sewer along north border
• No conflicts anticipated
• Water and Sewer along Southeast border
• Water along southwest border
• Sewer along northwest border
• No conflicts anticipated
• Stormwater lines along northeast and northwest borders
• Sewer line splits parcel
• Minimal green space in southern portion outside parking lot
• Minimal conflict anticipated
• Water along southeast border
• Sewer intersects parcel in northeast quadrant
• Minimal conflict anticipated
• Sewer lines in southwest portion and Stormwater ditch bisecting parcel
• Open green space throughout parcel
• Minimal conflict anticipated
• Water lines along eastern border
• Open areas on school property
• No conflicts anticipated
• Water lines along west and south borders
• No conflicts anticipated
13
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3.3 for Prioritf
The priority parcels were reviewed in the field by EPA, city, and SRWA staff. Important considerations
included slopes, available vacant land area, size of urban drainage area, drainage patterns, existing
mature trees, and potential presence of hazardous materials (e.g., underground storage tanks).
Following the field investigation and review by the Community Team, three priority parcels were
screened out for significant constraints:
• Parcel 104 339, the City Hall property, was removed from the list due to a combination of steep
slopes, intensive use of parking, and lack of space for green infrastructure. This property
remains a candidate for rainwater harvesting, which could support Clarkesville's landscaping
maintenance activities. While a green roof was considered, the roof on City Hall had been
recently replaced, and other properties offered more promising green roof opportunities.
• Parcel 069 043 was removed because the gas station, which is currently under operation,
presents a potential conflict with green infrastructure due to existing underground storage tanks
and the use of hazardous materials. If infiltration were used, it might have to be lined and would
be less effective than other green infrastructure opportunities. The identification of this
constraint was based on visual assessment in the field. Spatial data can be used to screen for
these site constraints prior to field visits. The USEPA Envirofacts website
(http://www.epa.gov/enviro/facts/topicsearch.html) can be used to identify locations of
hazardous waste handlers. Some states maintain similar datasets. Spatial data might not include
all locations with hazardous materials constraints, and field visits are important for further
screening.
• Parcel 104 024 was removed because the drainage patterns did not provide a promising
opportunity for green infrastructure.
Several additional parcels were recommended by the city and reviewed in the field in addition to the
already prioritized parcels. Following the field investigation, the parcels were grouped into 11 sites that
were determined to provide promising opportunities with minimal apparent constraints. Exhibits 1
through 11 in Appendix C present conceptual recommendations for each selected site. Exhibits 10 and
11 represent sites that will be considered for development by the city in the future; more general
recommendations were provided for these sites.
The city selected four parcels for the development of preliminary cost estimates. Table 3-3 presents the
cost estimates for these four projects separately by type of BMP. The cost range reflects potential for
variation in a number of factors, including drainage area, size of the BMP, cost of labor and materials,
and site constraints. These costs are estimated at the planning-level and should be only used for
preliminary budgets until more detailed designs and cost estimates can be developed.
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Table 3-3. Preliminary, Planning-Level Cost Estimates for Select Priority Projects
Project
Estimated Scale1
Estimated Design,
Engineering, and
Construction Costs2
Source
Downtown Green Street (Exhibit 2)
Bioretention
Treat 0.35 acre impervious $55,000 to $74,000 King and Hagan
surface (2011)
Permeable Pavement
14 parking spaces
$50,000 to $60,000 Past project cost
estimates from EPA
engineers
Courthouse Annex (Exhibit 4)
Bioretention
Treat 0.33 acre impervious $52,000 to $70,000 King and Hagan
surface (2011)
Permeable Pavement
10 parking spaces
$40,000 to $50,000 Past project cost
estimates from EPA
engineers
Burned Parcels (Exhibit 10)
Green Roof (Parcel
069A131)
6,000 square foot roof
$96,000 to $129,000 USEPA(2013);
Whatley (2011)
Green Roof (Parcel
069A125)
2,000 square foot roof
$32,000 to $43,000 USEPA (2013);
Whatley (2011)
Bridge Street (Exhibit 11)
Green Roof (Parcel
069A134)
2,750 square foot roof
$44,000 to $59,000 USEPA (2013);
Whatley (2011)
1Drainage areas, parking space counts, and roof areas are subject to change once more detailed plans are developed.
2The cost to remove existing pavement or structures are not included in the estimates. Green roof costs reflect a relatively
simple, thin green roof design (i.e. extensive).
4 Code and Ordinance Review
The City of Clarkesville's Zoning Ordinance regulates much of the building and development activity
including, but not limited to, zoning, overlays, subdivision development, street design, stormwater
management, and impacts to individuals trees. USEPA used Tetra Tech's Green Infrastructure
Opportunity Checklist Tool to understand and describe where the City of Clarkesville's Zoning Ordinance
might present barriers to or opportunities for implementing a comprehensive green infrastructure
approach.
The Green Infrastructure Opportunity Checklist Tool is organized into the following five goals:
• Goal #1: Minimize effective or connected impervious area
• Goal #2: Preserve and enhance the hydrologic function of unpaved areas
• Goal #3: Harvest rainwater to enhance potable and nonpotable water supply
• Goal #4: Allow and encourage the use of multi-use stormwater controls
• Goal #5: Manage stormwater to sustain stream functions
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The checklist poses a list of questions under each of these goals, and the code reviewer enters the
answer based on the community's existing code. The checklist rates each item as important, very
important, or essential. To identify the key opportunities for improving the code, these ratings were
considered, along with how relevant each item was to Clarkesville's goals and unique characteristics.
Appendix D presents the results of the code review for the City of Clarkesville's zoning ordinance. The
following key opportunities were recommended as priorities for encouraging the application of green
infrastructure in Clarkesville:
1. Street and Parking Dimensions: Allow narrower street and travel lane widths with curb pullouts
for passing of large vehicles. More specifically, allow 10- to 12-foot travel lanes (or less); in
residential developments, allow street pavement widths of 18 to 22 feet. For parking, allow a
smaller minimum stall area so that at least some stalls can be 9 feet by 15 feet or smaller. While
not specifically prohibited, curb bumpouts/extensions could be encouraged near intersections
and mid-block for traffic-calming and bioretention opportunities.
2. Redevelopment: Include incentives for redevelopment through minor relaxation of site design
standards (i.e. stormwater retention) or other requirements. The undisturbed land (i.e.
greenfield) that might have been developed without the incentives would then continue to
provide stormwater management benefits. The City of Clarkesville might consider specific areas
for incentives, like the downtown, or have the incentives apply to redevelopment throughout
the city.
3. Setbacks: Reduce required setbacks to encourage clustering and open space design. Minimum
lot setbacks could be reduced to 20 feet in the front, 25 feet in the rear, and 8 feet on the side
for higher density residential development (1/2-acre lot or less in size). Further reductions in
setbacks beyond these recommendations could also be considered. At a minimum, these
reduced setbacks could be used as guidance for approving conservation subdivisions. The city
may also want to consider reducing setbacks for the more urban residential zoning districts like
R-1A, R-1B, and R-2.
4. Phased Disturbance of Vegetated Areas: In site plans, require that disturbance of vegetated
areas be phased to reduce erosion of topsoil.
5. Wetlands: Require that all development minimize hydrologic alteration to existing wetlands.
6. Stream Buffers: Increase the width of required stream buffers or extend stream buffer
requirements so that all development must preserve at least a 50-foot buffer.
7. BMP Maintenance: Require a BMP maintenance plan for all stormwater facilities.
8. Performance Standards: Develop additional stormwater performance standards for new
development and redevelopment, including standards for stormwater volume, water quality
treatment, and channel protection.
The code and ordinance review highlights a number of opportunities to improve the city's Zoning
Ordinance to encourage green infrastructure on existing and new development or redevelopment. The
key opportunities identified provide recommended priorities for the short-term, and the full checklist in
Appendix D provides a reference for continued code improvements.
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5 Potential Funding Sources
The multiple benefits of green infrastructure provide eligibility for a diverse array of funding sources.
Generally, green infrastructure projects may be eligible for funding programs that prioritize water
quality improvement, flood mitigation, and community green space, among other green infrastructure
benefits. The energy saving benefits of green infrastructure provide a leveraging opportunity with
energy efficiency-related funding. Funding might also be leveraged if a green infrastructure opportunity
is part of a housing or economic development project. Stormwater utilities provide communities with a
long-term funding source for green infrastructure as well as general stormwater improvement projects.
This section provides a review of available funding opportunities and highlights the most promising
sources for funding green infrastructure in Clarkesville.
S, II . ;. •-'.•-•
A number of programs exist that fund infrastructure projects to achieve water resource management
goals, and green infrastructure is well-supported by these programs. The following list summarizes the
most relevant funding opportunities for the City of Clarkesville in this category:
• USEPA Clean Water Act Nonpoint Source Grant (Section 319 Grants): Funded by USEPA
through the Clean Water Act and administered by GAEPD, these grants provide funding for best
management practices (BMPs) and other water quality improvement efforts. They require a 40
percent non-federal match that can be met through local funds, in-kind services, or other non-
federal sources. Applications are typically due in the fall of each year, and awards are
announced in the spring.
https://epd. Georgia. aov/section-319h-aeoraias-nonpoint-source-implementation-arant
• USEPA Clean Water State Revolving Fund (CWSRF): Administered by the Georgia Environmental
Finance Authority, the CWSRF provides low-interest loans for a variety of water-related
infrastructure projects including bioretention, tree planting, green roofs, permeable pavement
and cisterns. Recent projects include the construction of stormwater BMPs in Sandy Springs, GA.
A 1 percent interest rate reduction is available for recycling and water reuse projects that
replace potable sources with non-potable sources (under "Conservation" projects).
http://gefa.cieorciia.ciov/clean-water-state-revolvinci-fund
• National Fish and Wildlife Foundation (NFWF) Five Star and Urban Waters Restoration
Program: The program brings together funding from multiple government agencies, non-profit
organizations, and private companies into a single grant application process focused on funding
projects that restore water quality, watersheds and the habitats in urban areas. Eligible projects
may include but are not limited to bioswales, permeable pavers, bioretention, green roofs,
downspout disconnection, installation of native vegetation, and wetlands restoration. Awards
range from $20,000 to $50,000 with an average size of $30,000, and 40 to 50 grants are
awarded per year. The application deadline occurs once per year in February and awards are
announced in July. A 50 percent non-federal match is required, and applications offering a
greater match are considered more competitive.
h ttp ://www.nfwf. ora/fivestar/Paaes/2015RFP. aspx
• U.S. Department of Transportation (USDOT) Transportation Alternatives Program: The
Transportation Alternatives Program provides funding for many activities relating to highways
including stormwater management, control, and water pollution prevention or abatement
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related to highway construction or due to highway runoff. Projects involving streetscaping and
corridor landscaping might also be eligible. For communities like Clarkesville with a population
of less than 5000, grants are administered through Georgia Department of Transportation
(GADOT) and are part of its Transportation Enhancement Program. Most awards require a 20
percent state or local match.
http://www.fhwa.dot.gov/environment/transportation alternatives/
http://www.dot.qa.gov/IS/Fundmq/TEtttab-2
U.S. Department of Agriculture (USDA) Rural Assistance Program, Water and Waste Disposal
Direct Loans and Grants: Available for rural communities with populations less than 10,000, this
program funds water and waste disposal systems, specifically construction, land acquisition,
legal fees, engineering fees, capitalized interest, equipment, initial operation and maintenance
costs, project contingencies, and other approved costs. The project must benefit primarily rural
users, and the applicant must be unable to obtain other funding at affordable rates. Loans and
grants are awarded; however, limited grants are available.
h ttp ://www. rurdev. usda.qo v/U WP-dispdirectloansgran ts.htm
Designation as a WaterFirst Community: The City of Clarkesville is also seeking designation as a
WaterFirst Community from the Georgia Department of Community Affairs. The designation
requires a community to take a proactive and collaborative approach in protecting water
resources. While working towards this designation, the city will be exposed to resources and
partnerships that will help strengthen their ability to implement green infrastructure. The
recognition associated with being designated a WaterFirst Community will continue to support
the city's efforts in advancing green infrastructure.
While landscaping is a component of green infrastructure, funding for community beautification and
other landscaping efforts could be applied to the vegetation costs of green infrastructure. Two Georgia-
based programs that provide funding for vegetation-related projects are described below. If these
programs are used, it will be important to propose a green infrastructure project that supports the
specific goals of each program.
• GADOT GATEway Grant Program: The GATEway Grant Program provides funding for roadside
beautification along state routes. The funds can be used only for landscape plant material and
its installation. The City of Demorest received $26,030 for roadside beautification from this
program.
http://www.dot.qa.qov/IS/Fundinq/Gateway
• The Garden Club of Georgia Historic Landscape and Garden Grant: Local governments and non-
profit organizations are eligible to apply for funding to protect or restore historic gardens or
other landscapes or promote public awareness of these features. The program requires a 50
percent match, and the funding is provided for one year at a maximum of $3,000. The Garden
Club of Georgia provides this funding through a partnership with the Georgia Department of
Natural Resources Historic Preservation Division, the Southeast Regional Office of the National
Park Service, the Cherokee Garden Library at the Atlanta History Center, and the Georgia
Department of Economic Development, http://qardenclub.uqa.edu/qardenqrant.html
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5,3 to
Green infrastructure can improve energy efficiency during warm months by shading impervious area,
which decreases a building's temperature and reduces the overall heat island effect in urban areas.
Green roofs provide the most direct form of energy savings by insulating buildings from heat loss during
the winter and over-heating during the summer. While there may be other funding programs available,
the following program has funded many energy saving projects throughout Georgia and the United
States.
• Energy Efficiency and Conservation Block Grant Program: The U.S. Department of Energy's
Energy Efficiency and Conservation Block Grant Program provides funding to cities,
communities, states, and other entities to develop, promote, implement, and manage energy
efficiency and conservation projects. Green roofs and other green infrastructure that help
conserve energy can be eligible for these block grants. In Georgia, 28 communities have
received this funding for a variety of energy-saving projects.
http://enerav.ciov/eere/wipo/enerciv-efficiencv-and-conservation-block-cirant-prociram
to
Projects that seek to provide economic development support to disadvantaged communities can often
be directly linked to one or more green infrastructure opportunities. For example, green infrastructure
can be integrated into the stormwater management design within an affordable housing project. If a
development project seeks to increase jobs, green infrastructure may provide opportunities for
additional employment through its long-term required maintenance. Any type of economic
development effort may include green infrastructure, and future streetscaping projects could present an
important leveraging opportunity.
The following list of funding programs could provide opportunities to leverage economic development
funding for green infrastructure.
• Appalachian Regional Commission (ARC) Grants: ARC is a federal, state, and local partnership
working within the Appalachian Region to increase job opportunities and improve opportunities
for the people of Appalachia to compete in the global economy. The program typically awards
grants to state and local agencies and governmental entities (e.g., economic development
authorities), local governing boards (e.g., county councils), and nonprofit organizations (e.g.,
schools and organizations that build low-cost housing). ARC prioritizes grant awards based on
economic status maps. Habersham County currently has a status of transitional and would be
eligible for a grant with a 50 percent or greater match. Habersham County received a $300,000
grant ($620,000 total including match) for water and sewer Improvements in FY2013.
http://www.arc.Qov/fundinQ/ARCGrantsandContracts.asp
• U.S. Economic Development Administration (USEDA) Economic Development Assistance
Programs: USEDA administers this program to provide funding for a range of business and
industrial development activities that create or retain jobs, including infrastructure
development. The funding consists of both grants and loans.
h ttp://www. gran ts. Qov/web/gran ts/view-opportunity.html?oppld=248297
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• Community Development Block Grant (CDBG) Program: CDBG funding is provided by the U.S.
Department of Housing and Urban Development and administered by the Georgia Department
of Community Affairs. The program requires that at least 70 percent of the funds be used for
efforts that benefit low- and moderate-income persons. Green infrastructure could be part of a
CDBG-finance project. For example, the City of Chicago used CDBG funds to install a new green
roof on its historic Cultural Center.
http://www.dca.state.Qa.us/communities/cdbQ/
•• ' :.,. .•, .• ? '"• - :; .• .. /.i'ty
Across the U.S., stormwater utilities are used by local governments of all sizes to provide a consistent
and reliable funding source for stormwater system improvement and maintenance. A stormwater utility,
much like a water or sewer utility, provides a framework for coordinating responsibilities, generating
funding, and planning for short-term and long-term needs. Stormwater utilities are typically funded by a
stormwater fee that is administered using an equitable structure across all users within the jurisdiction.
The following are some advantages of a stormwater utility:
• Provides a dedicated stream of funding for capital stormwater improvement projects and
operation and maintenance.
• Finances cost shares for federal and state grants.
• Allows for a coordinated effort and overall cumulative progress on major stormwater concerns,
providing the ability to address flooding, water quality, and other needs in tandem.
• Provides options for incentives (e.g., fee credits) to encourage voluntary practices, like green
infrastructure.
With a water and sewer utility already in place, Clarkesville has an advantage over other small local
governments without these utilities. A stormwater fee can be added to the current utility billing
structure, which reduces the cost of setting up and administering a fee. When applying for loans, the
stormwater utility can borrow against the water and sewer utility's track record. Linking the stormwater
utility with the water and sewer utility also provides additional funding flexibility. Each utility can have
its own dedicated funding while loans between the utilities can occur.
There are a variety of approaches to developing stormwater utilities and implementing fees. The
simplest approach is to apply a flat rate to all users. When implementing a flat rate, a city can limit
potential objections and legal exposure by gaging community support for the rate and evaluating
whether a flat rate is sufficiently equitable across the different sizes and uses of customer properties.
Tiered or custom rate structures can be developed based on impervious surface, parcel size, or another
metric related to stormwater runoff generation. Some jurisdictions choose to fund stormwater utilities
through a property tax (i.e., ad valorem tax), which can be appropriate if property value is closely tied to
the amount of on-site impervious surface.
The process of creating a stormwater utility involves establishing goals and objectives, determining an
administrative structure, gathering stakeholder input, and researching equitable fee structures. Tools
and resources are available to help local governments with this process. Most notably, the University of
North Carolina Environmental Finance Center has developed the Georgia Stormwater Utility Dashboard,
an on-line tool for stormwater utility planning.
http://www.efc.soQ.unc.edu/resHb/item/Qa-stormwater-utility-dashboard
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In addition, the following list provides examples of relatively small local governments in Georgia who
operate stormwater utilities and provide examples of frameworks and fee structures for consideration
(University of North Carolina Environmental Finance Center, 2014):
Auburn, GA (Barrow/Gwinnett Counties)
• Service population 6,887
• Administers a flat rate for residential, tiered rate for nonresidential
• Website: www.citvofauburn-aa.ora/index.as[}x?nid=129
Austell, GA (Cobb County)
• Service population 6,581
• Administers a flat rate for residential, custom rate for nonresidential, credit program
• Website: www.austellcia.ciov
Avondale Estates (DeKalb County)
• Service population 2,960
• Administers a flat rate for residential, custom rate for nonresidential, credit program
• Website: www.avondaleestates.orci/i3ublic works.html
Camilla (Mitchell County)
• Service population 5,360
• Administers a flat rate for residential, custom rate for nonresidential, credit program
• Website: www.camillacia.net/stormwater.shtml
Most of the above communities include a credit program as part of their stormwater fee structure,
which provides reduced fees or other incentives for users to implement voluntary practices including
rain barrels, downspout disconnection, natural area preservation, and impervious surface reduction. All
four communities administer a flat rate for residential and either custom or tiered rates for
nonresidential.
5 «:
The review of available funding sources revealed a number of opportunities to seek funding support and
leverage multiple sources for green infrastructure in the City of Clarkesville. The water resources-related
funding sources would be applicable to all of the recommended projects. However, Clarkesville is likely
to achieve greater success if multiple and diverse funding sources are pursued. The projects involving
stormwater wetlands and/or detention (Appendix C, Exhibits 6, 7, and 8) should be prioritized for the
water resource-related funding sources. While these projects can provide many co-benefits, a more
direct case for energy savings, landscaping, or economic development can be made for smaller projects
that are integrated into other uses. In addition, Exhibits 2, 3, and 6 all could be designed to treat
highway runoff and would be most appropriate for the USDOT Transportation Alternatives Program.
When considering the funding sources that are not directly related to stormwater improvements, it is
likely that the city will need to pursue at least two separate sources of funding. For example, the
landscaping-related funding would be applied towards the vegetation costs of green infrastructure, and
the remaining costs could be funded through a 319 grant or other relevant source with a local match.
The Historic Landscape and Garden Grant could provide relevant funding to the Mauldin House site
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(Exhibit 5) if the specific requirements of the grant are met. Future streetscaping projects can also be
coordinated with green infrastructure implementation within the downtown area. Exhibit 2 provides a
promising opportunity to provide streetscaping along with stormwater treatment, and landscaping-
related funding could be applied to the vegetation costs for this project.
Any green infrastructure project that would increase shading of impervious surfaces could be eligible for
energy-efficiency-related funding. A green roof project would provide the most directly relevant
proposal for this funding (Exhibits 10 and 11).
Many of the proposed projects include bioretention that will require long-term maintenance. This type
of maintenance provides an opportunity for creating jobs for unskilled workers. While a single
bioretention cell results in minimal additional employment, a large number of bioretention cells
throughout the city could generate employment, provide career development, and increase
opportunities for those who are otherwise unskilled and unemployed. By proposing to build enough
green infrastructure to create additional employment, Clarkesville could leverage economic
development funding with water resource-related funding.
Beyond the current proposed sites, green infrastructure could be integrated into any affordable housing
project proposed or planned throughout the city. To achieve this, it would be important for multiple city
and County departments to work together and plan to include green infrastructure in grant proposals
for affordable housing or other economic development projects.
As discussed in Section 5.5, a stormwater utility and fee structure can provide a consistent funding
source for financing local cost share and a broader stormwater management program. The city could
implement an initial program with a minimal flat rate added to the sewer/water utility bill for all users
and then research more complex fee structures tied more closely to impervious surface and/or other
stormwater-related metrics. Another option would be to model the fee structure on the example
communities presented above, with a flat rate for residential and a custom or tiered rate for
nonresidential. For further guidance on fee structures, Clarkesville and other local governments in
Georgia can use the Georgia Stormwater Utility Dashboard, an on-line tool for stormwater utility
planning, http://www.efc.soa.unc.edu/reslib/item/cia-stormwater-utilitv-dashboard
In summary, the recommended funding approach for green infrastructure in Clarkesville is to:
• Continue to pursue WaterFirst Community designation.
• Investigate feasibility and public interest in a stormwater utility for use in funding projects and
grant cost share.
• Collaborate with affordable housing and economic development programs to find opportunities
for green infrastructure and leveraging with ARC grants, USEDA Economic Development
Assistance Programs, and CDBG program.
• Pursue site-specific funding:
o Parcel 102 017 and Methodist Church property (Appendix C, Exhibits 7 and 8
respectively): Pursue USEPA Clean Water Act Nonpoint Source Grant (Section 319
Grants) USEPA CWSRF, USDA Rural Assistance Program, Water and Waste Disposal
Direct Loans and Grants.
o Grant Street and Parcel 102 087 (Appendix C, Exhibits 3 and 6 respectively): Pursue
USDOT Transportation Alternatives Program first and then consider more general water
resource-related funding (Section 319 Grants, NFWF, CWSRF, and USDA).
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Downtown Area (Appendix C, Exhibit 2 - Green Street): Pursue combination of GADOT
GATEway Grant Program, USDOT, and water-resource-related funding (Section 319
Grants, NFWF, CWSRF, USDA); leverage with the city's streetscape planning.
Parcel 102 086 (Appendix C, Exhibit 5 - Mauldin House): Investigate leveraging with a
project that meets requirements for The Garden Club of Georgia Historic Landscape and
Garden Grant.
Parcels 069A009, 069 032 and 104 041 (Appendix C, Exhibits 1, 4, 9 respectively):
Investigate leveraging with Energy Efficiency and Conservation Block Grant Program due
to reduced heat island effect from the use of grass pavers.
Parcels 069A125, 069A131, 069A134 (Exhibits 10 and 11, respectively): Investigate
leveraging with Energy Efficiency and Conservation Block Grant Program due to
insulation effect of green roofs.
6 Strategy Summary
The components of this strategy provide the City of Clarkesville with basic building blocks for green
infrastructure tailored to the city's goals and objectives. Other local governments can apply this
framework and approach to their own community using the steps outlined in this strategy. The selection
of site-specific opportunities was based on a comprehensive prioritization using remote spatial data
followed by an on-site review of opportunities and constraints. The recommendations described and
illustrated in Appendix C provide project concepts that can be further evaluated based on benefits,
costs, and feasibility. The code and ordinance review highlights a number of opportunities to improve
the city's Zoning Ordinance to encourage green infrastructure on existing and new development or
redevelopment. The key opportunities identified support recommended priorities for the short-term,
and the full checklist in Appendix D provides a reference for continued code improvements. Finally,
funding sources were identified with Clarkesville's goals and site-specific opportunities in mind.
Based on discussions with the community team and the evaluations described above the following
general approach is recommended for implementing green infrastructure in Clarkesville:
1. Investigate property owner interest, cost and general feasibility of site-specific opportunities
and select a subset for pursuing more detailed conceptual designs.
2. Include consideration of the identified key opportunities (Section 4) in future zoning code
revisions.
3. Continue to pursue WaterFirst Community designation.
4. Investigate feasibility and public interest in a stormwater utility for use in funding projects and
grant cost share.
5. Collaborate with affordable housing and economic development programs to find opportunities
for green infrastructure and leveraging with ARC Grants, USEDA Economic Development
Assistance Programs, and the CDBG program.
6. Pursue site-specific funding for Appendix C Exhibits 1-11 as appropriate based on further
planning and evaluation.
This approach should evolve over time based on changing needs within the city and as new
opportunities for partnership and funding emerge. With these basic steps, the City of Clarkesville can
continue to build experience with green infrastructure and realize its multiple benefits including water
quality improvement, flood prevention, beautification, and community development.
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Clarkesville's recent growth and redevelopment present stormwater management challenges. As a small
city, its staff has been proactive about partnering with public and private entities and finding creative
solutions to urban stormwater issues. Their efforts, exemplified by this strategy, are helping to address
stormwater challenges and prevent larger problems in the future. By outlining goals, priorities, code
improvements, project opportunities, and funding sources, the City of Clarkesville's strategy provides a
model approach for small, unregulated communities to successfully pursue green infrastructure.
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7 References
CensusViewer. 2012. Clarkesville, Georgia Population: Census 2010 and 2000 Interactive Map,
Demographics, Statistics, Quick Facts.
.
Accessed October 8, 2014.
City-Data.com. 2013. Clarkesville, Georgia. .
Accessed October 8, 2014.
City of Clarkesville. 2013. Community Profile, .
Accessed October 8, 2014.
Georgia Department of Community Affairs. 2014. Georgia Main Street.
. Accessed October 8, 2014.
Georgia Environmental Protection Division (GAEPD). 2014. Draft Georgia 2014 305(b)/303(d) List.
. Accessed March 27, 2015.
Habersham County Georgia. 2014. County Facts. .
Accessed October 8, 2014.
King, D. and P. Hagan. 2011. Costs of Stormwater Management Practices In Maryland Counties. University
of Maryland Center for Environmental. Science. Technical Report Series No. TS-626-11.
Accessed December 19, 2014.
U.S. Census Bureau. 2014. State and County QuickFacts, Habersham County, Georgia.
. Accessed October 8, 2014.
U.S. Environmental Protection Agency (USEPA). 2013. Green Roofs.
. Accessed December 19, 2014.
University of North Carolina Environmental Finance Center. 2014. Georgia Stormwater Utility
Dashboard. Accessed October 10, 2014.
Whatley, M. B. 2011. Life-cycle cost-benefit analysis of green roofing systems: the economic and
environmental impact of installing green roofs on all Atlanta public schools. Georgia Institute of
Technology. Accessed December 19, 2014.
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Appendix A: Parcel Prioritization Detailed Methods and Results
Ten indicators were identified for use in scoring the suitability of Clarkesville city parcels as sites for
green infrastructure improvement. For each indicator, the parcels were ranked from 1 to 10, with 1
representing the worst opportunity for green infrastructure and 10 representing the best opportunity.
Binary indicators, meaning an indicator is either present or not, received a score of 1 or 10 respectively.
The scores were then averaged to achieve a cumulative score across all indicators. For the methods
described here, all indicators were weighted equally (although some communities might choose to
weight some indicators) and those with the highest cumulative scores were the most suitable for green
infrastructure improvement.
There were 1,265 parcels that intersected the city limit boundary with a 100-meter buffer (to capture
adjacent parcels of interest). These parcels were evaluated using the GIS data supplied by the City of
Clarkesville. The data used in the ranking analysis were cataloged and analyzed wholly within a GIS
interface (ESRI, ArcGIS). For all data, data quality measures met those set forth in standards outlined by
the Federal Geographic Data Committee.
The following list describes the prioritization indicators and how parcels were scored based on these
indicators. Additional indicators evaluated but not used in the final prioritization and scoring are
described in Appendix B.
1. Publicly Owned Parcels - Land costs generally are minimized by using existing public lands;
therefore, a higher priority was placed on publicly owned parcels (Table A-l).
Table A-l. Scoring for Publicly Owned Parcels
Publicly Owned Parcels Code Ranking
Parcel is designated as public yes 10
Parcel has other specified designation no 1
2. Impervious Surfaces - The imperviousness of the land within a parcel is a direct indicator of the
degree of stormwater management opportunity within the parcel. The National Land Cover Dataset
(NLCD) was used to determine the percent of impervious surface within each parcel (Figure A-l).
http://www.mrlc.ciov/nlcd2011.i3hi3 A higher priority was placed on parcels with higher impervious
surface (Table A-2).
Table A-2. Scoring for Impervious Surfaces
Percent Impervious Surface within Parcel Ranking
75 -100% 10
50 - 75% 7.5
25 - 50% 5
0 - 25% 2.5
A-!
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Legend
Parcels
1 City Limits
Impervious Surfaces
Percent
1-25
26-50
51-75
', 76-100
Clarkesville Site Prioritization: Impervious Surfaces
NAO_1983_SiaiePlare_Georgia_Wes!_FIPS_1002_Feet
Map Produced 07 -01-2014 -A Porteous
Figure A-1. Impervious surfaces with parcels for a select subsegment of Clarkesville
3. Parcel Size - The overall size of the project depends in part on the overall size of the parcel selected
during the prioritization process. Parcels with a larger area were prioritized (Table A-3).
Table A-3. Scoring for Parcel Size
Parcel Size (acres)
Ranking
1.52-180.98
10
0.61-1.51
7.5
0.33 - 0.60
0.005 - 0.33
2.5
4. Located in a Priority Watershed - The City of Clarkesville identified the Rocky Branch and
Stormwater Creek watersheds as priorities for green infrastructure. These watersheds contain a
significant amount of development, and their streams have been noticeably altered by stormwater
flows. These watersheds also drain to the impaired segment of the Soque River. If the majority of a
parcel area overlapped with one of these watershed boundaries, then this parcel was prioritized
(Table A-4).
A-2
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Table A-4. Scoring for Priority Watershed Status
Priority Watershed Status Ranking
Majority (>50%) located within Rocky Branch or Stormwater Creek 10
Majority (>50%) NOT located within Rocky Branch or Stormwater Creek 1
5. Infiltration Capacity - The mapped hydrologic soils groups (HSG) were used as an initial estimate for
the infiltration rate and storage capacity of the soils. Sites where mapped HSGs have infiltration
rates suitable for infiltration practices received higher priority for further investigation. The percent
of parcel area within each category was calculated. The parcel received the ranking associated with
the HSG that represents the largest percent area within the parcel (Table A-5).
Table A-5. Scoring for Hydrologic Soil Groups
Hydrologic Soil Groups Ranking
A - Soils with high infiltrations rates. Usually deep, well-drained sands or gravels. Little runoff. 10
B - Soils with moderate infiltration rates. Usually moderately deep, moderately well-drained soils. 7.5
C - Soils with slow infiltration rates. Soils with finer textures and slow water movement. 5
D - Soils with very slow infiltration rates. Soils with high clay content and poor drainage. High amounts of
runoff.
6. Located in a Priority Characterization Area -Through discussions with the community team, several
priority areas for green infrastructure were identified within the city. Each of these areas was ranked
based on potential multiple benefits that green infrastructure would provide if located on these
parcels.
First, the recently burned parcels, located downtown, received the highest score of 10 based on
their prominence in the community. The area of burned parcels downtown, in conjunction with
green infrastructure, would provide additional beautification of the downtown area as well as a
cost-effective opportunity for green infrastructure, given that construction would occur along with
re-development of the parcels.
Parks and schools generally provide promising green infrastructure opportunities due to relatively
large areas of available open space as well as potential for education and outreach and enhanced
aesthetics. Proximity to parks and schools can also enhance community benefits. Parcels within 200
feet of a park or school were given a score of 7.5.
In addition to the above areas, the City of Clarkesville has defined four characterization areas that
generally represent focus areas for planning in the city (Figure A-2). Green infrastructure could
provide multiple benefits within these areas, including enhanced recreation, aesthetics, and
education and outreach. The park characterization area was given a score of 7.5, to be consistent
with the scoring of other parks. The other characterization areas, representing centrally located and
high density parcels, were given a score of 5.
Finally, a score of 7.5 was given to any parcels within the portion of the downtown area where a
streetscape improvement project has not yet been implemented. If a parcel met more than one
criterion, that parcel was given the highest possible score. Table A-6 summarizes the above the
rankings.
A-3
-------
Table A-6. Scoring for Priority Characterization Areas
Clarkesville Priority Characterization Area
Burned parcel on Washington Street
Park Prioritization Area or Proximity to other parks and schools (within 200 feet)
Remaining opportunity for streetscaping
Downtown, Old Town, and Washington Street characterization areas
Parcel NOT located within any characterization area or other priority area
Ranking
10
7.5
7.5
5
2.5
Legend
Characterization Areas
Park
| Downtown
^B Old Town
Washington Street
Parcels
N 0 075 15
Clarkesville Site Prioritization: Characterization Areas
D 1983 Stfl!eP'ane_Geo'gia_WeM_FIPS 100? F
Map Produced 07-01 -201* - A 'Porteius
Figure A-2. Characterization areas as defined in the zoning GIS files supplied by the City of Clarkesville
7. Proximity to Maintenance Need - The stormwater inventory delivered by the City of
Clarkesville and maintained by the public works department contains point locations of
infrastructure maintenance needs throughout the city. Green infrastructure could help solve a
maintenance issue or present a more cost-effective opportunity when implemented in tandem
with infrastructure repair. A parcel within 200 feet of an existing or proposed maintenance need
received a priority score for this criterion (Table A-7).
A-4
-------
Table A-7. Scoring for Existing Maintenance Needs
Proximity to an Existing Maintenance Need Code Ranking
Parcel is within 200 feet of an existing maintenance need Yes 10
Parcel is NOT within 200 feet of an existing maintenance need No 1
8. Proximity to Stormwater Structural Damage - The stormwater inventory delivered by the City
of Clarkesville and maintained by the public works department contains point locations of
stormwater structural damage throughout the city. Green infrastructure could present a more
cost-effective opportunity when implemented in tandem with infrastructure repair. A parcel
within 200 feet of an existing stormwater structural damage received a priority score for this
criterion (Table 8).
Table A-8. Scoring for Existing Stormwater Structural Damage
Proximity to Existing Stormwater Structural Damage Code Ranking
Parcel is within 200 feet of existing stormwater structural damage Yes 10
Parcel is NOT within 200 feet of existing stormwater structural damage No 1
9. Proximity to Stormwater Inlet, Catchment Basin, or Conveyance Structure - The stormwater
inventory delivered by the City of Clarkesville and maintained by the Public Works Department
contains point locations of stormwater inlets, catchment basins, and conveyance structures
throughout the city (Figure A-3). These are all indicators of stormwater drainage that can help
identify viable green infrastructure opportunities. A parcel within 200 feet of these indicators
received a score of 10 for this indicator (Table A-9).
Table A-9. Scoring for Stormwater Inlet, Catchment Basin, or Conveyance Structure
Proximity to Stormwater Inlet, Catchment Basin, or Conveyance Structure Code Ranking
Parcel is within 200 feet of a Stormwater Inlet, Catchment Basin, or Conveyance Structure Yes 10
Parcel is NOT within 200 feet of Stormwater Inlet, Catchment Basin, or Conveyance Structure No 1
10. Percent Slope
Steep slopes can affect the cost-effectiveness and feasibility of green infrastructure. To screen
out parcels with very high slopes, the parcels were scored based on quartiles of percent slope
(Table A-10).
Table A-10. Scoring for Percent Slope
Percent Slope Ranking
0-6.20% Slope 10
6.21-9.47% Slope 7.5
9.48-12.59% Slope 5
12.60-30.95% Slope 2.5
A-5
-------
Legend
Structure Type
|C; Catch Basin
Curb Inlet
Drop Inlet
Yard Inlet
O End of Pipe
Fiared End Section
Headwall
Double Headwall
Junction
Other
Box Culvert
Ponds
Open Ditch
Closed Pipe
Stream/Creek
SW Line Maintenance Issue
^^B Replace
Jet/Vac
^^B Erosion Measures
Vegetation
Other
Maintenance Needed
?-
Structural Damage
Parcels
| City Limits
Clarkesville Site Prioritization: Stormwater
Figure A-3. Stormwater inventory data displayed on a downtown portion of Clarkesville
A-6
-------
Table A-ll presents the highest scoring 100 parcels resulting from the parcel prioritization.
A-7
-------
Table A-1 I. Detailed Prioritization Results
Rank
Order
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
10.00
11.00
12.00
13.00
14.00
15.00
16.00
17.00
Parcel Code
102 093
069 032
069A009
104 339
102 086
102 087
069 043
102 017
104 041
104 024
069A137
069A136
102 013
069A143
104 289
069A141
069A138
Publicly
Owned
Parcels
10.00
10.00
10.00
10.00
10.00
10.00
1.00
10.00
10.00
10.00
10.00
10.00
1.00
1.00
1.00
1.00
1.00
Impervious
Surface
7.50
5.00
10.00
7.50
7.50
5.00
7.50
2.50
7.50
5.00
10.00
10.00
5.00
10.00
5.00
10.00
10.00
Parcel
Size
7.50
7.50
10.00
10.00
7.50
7.50
7.50
10.00
10.00
10.00
2.50
2.50
7.50
2.50
10.00
2.50
2.50
Priority
Watershed
10.00
10.00
1.00
10.00
10.00
10.00
10.00
10.00
1.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
Hydrologic
Soil
Groups
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
Priority
Charact.
Area
5.00
5.00
7.50
5.00
5.00
5.00
7.50
7.50
5.00
5.00
5.00
5.00
7.50
5.00
5.00
5.00
5.00
Maint.
Need
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
Struct.
Damage
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
1.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
Sw.
Catch/
Conv.
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
% Slope
10.00
10.00
7.50
2.50
5.00
7.50
10.00
2.50
7.50
10.00
2.50
2.50
7.50
10.00
7.50
10.00
10.00
Composite
Score
8.75
8.50
8.35
8.25
8.25
8.25
8.10
8.00
7.85
7.85
7.75
7.75
7.60
7.60
7.60
7.60
7.60
A-8
-------
Rank
Order
18.00
19.00
20.00
21.00
22.00
23.00
24.00
25.00
26.00
27.00
28.00
29.00
30.00
31.00
32.00
33.00
34.00
Parcel Code
069A135
102 040
102 116
069A131
069A012
069 044
069 041
102 014
102 016
104 319
104 320
104 275
104 296
102 098
104 265
104 023
106 096
Publicly
Owned
Parcels
1.00
1.00
1.00
10.00
10.00
1.00
1.00
1.00
10.00
1.00
1.00
1.00
1.00
1.00
1.00
10.00
10.00
Impervious
Surface
10.00
2.50
10.00
10.00
10.00
2.50
2.50
2.50
2.50
5.00
5.00
5.00
5.00
7.50
7.50
5.00
5.00
Parcel
Size
5.00
10.00
7.50
2.50
5.00
7.50
7.50
10.00
10.00
5.00
5.00
5.00
7.50
5.00
10.00
10.00
10.00
Priority
Watershed
10.00
10.00
1.00
10.00
1.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
1.00
1.00
Hydrologic
Soil
Groups
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
Priority
Charact.
Area
5.00
5.00
7.50
10.00
7.50
7.50
7.50
7.50
7.50
5.00
5.00
5.00
5.00
5.00
2.50
2.50
2.50
Maint.
Need
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
Struct.
Damage
10.00
10.00
10.00
1.00
10.00
10.00
10.00
10.00
1.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
Sw.
Catch/
Conv.
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
% Slope
7.50
10.00
10.00
2.50
2.50
7.50
7.50
5.00
5.00
10.00
10.00
10.00
7.50
7.50
5.00
7.50
7.50
Composite
Score
7.60
7.60
7.45
7.35
7.35
7.35
7.35
7.35
7.35
7.35
7.35
7.35
7.35
7.35
7.35
7.35
7.35
A-9
-------
Rank
Order
35.00
36.00
37.00
38.00
39.00
40.00
41.00
42.00
43.00
44.00
45.00
46.00
47.00
48.00
49.00
50.00
51.00
Parcel Code
104 113
104 039
069A038
102 043
069A125
102 117
069 029
069A011
069A148
069A147
069A146
069 042
069 035
104 318
102 091
102 097
069A133A
Publicly
Owned
Parcels
10.00
10.00
10.00
1.00
10.00
1.00
10.00
10.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
Impervious
Surface
2.50
5.00
2.50
5.00
10.00
10.00
2.50
10.00
7.50
7.50
7.50
2.50
2.50
2.50
5.00
5.00
5.00
Parcel
Size
10.00
7.50
10.00
10.00
2.50
7.50
2.50
2.50
5.00
5.00
5.00
5.00
10.00
7.50
2.50
2.50
5.00
Priority
Watershed
1.00
1.00
1.00
10.00
10.00
1.00
10.00
1.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
Hydrologic
Soil
Groups
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
Priority
Charact.
Area
2.50
2.50
2.50
2.50
10.00
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
5.00
5.00
5.00
5.00
Maint.
Need
10.00
10.00
10.00
10.00
1.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
Struct.
Damage
10.00
10.00
10.00
10.00
1.00
10.00
1.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
Sw.
Catch/
Conv.
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
% Slope
10.00
10.00
10.00
7.50
10.00
7.50
10.00
2.50
2.50
2.50
2.50
7.50
2.50
7.50
10.00
10.00
7.50
Composite
Score
7.35
7.35
7.35
7.35
7.20
7.20
7.10
7.10
7.10
7.10
7.10
7.10
7.10
7.10
7.10
7.10
7.10
A-IO
-------
Rank
Order
52.00
53.00
54.00
55.00
56.00
57.00
58.00
59.00
60.00
61.00
62.00
63.00
64.00
65.00
66.00
68.00
67.00
Parcel Code
104 276B
104 037
104 262
104 313
104 219
102 194
069A072
071 032
102 141
102 012
102 113
069A010
104 132
106 104
104 114
102 018
069A144
Publicly
Owned
Parcels
1.00
10.00
1.00
1.00
1.00
1.00
10.00
10.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
Impervious
Surface
5.00
5.00
2.50
2.50
2.50
2.50
5.00
2.50
5.00
2.50
10.00
7.50
7.50
7.50
10.00
2.50
10.00
Parcel
Size
7.50
10.00
7.50
7.50
10.00
10.00
10.00
10.00
7.50
10.00
2.50
7.50
10.00
10.00
10.00
7.50
2.50
Priority
Watershed
10.00
1.00
10.00
10.00
10.00
10.00
1.00
1.00
10.00
10.00
1.00
10.00
1.00
1.00
1.00
10.00
10.00
Hydrologic
Soil
Groups
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
Priority
Charact.
Area
5.00
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
7.50
5.00
2.50
2.50
2.50
7.50
5.00
Maint.
Need
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
Struct.
Damage
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
1.00
10.00
10.00
10.00
10.00
10.00
Sw.
Catch/
Conv.
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
% Slope
5.00
5.00
10.00
10.00
7.50
7.50
5.00
7.50
7.50
7.50
10.00
10.00
10.00
10.00
7.50
2.50
2.50
Composite
Score
7.10
7.10
7.10
7.10
7.10
7.10
7.10
7.10
7.10
7.10
6.95
6.95
6.95
6.95
6.95
6.85
6.85
A-ll
-------
Rank
Order
69.00
70.00
71.00
72.00
73.00
74.00
75.00
76.00
77.00
78.00
79.00
80.00
81.00
82.00
83.00
84.00
85.00
Parcel Code
102 129
069A145
102 085
102 034
104 299
104 245B
104 280
104 264
104 230
104 259
102 194
104 140
104 258
104 260
104 279
104 232
104 148
Publicly
Owned
Parcels
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
Impervious
Surface
2.50
10.00
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
Parcel
Size
10.00
2.50
7.50
5.00
7.50
5.00
10.00
5.00
10.00
5.00
10.00
10.00
7.50
7.50
10.00
7.50
10.00
Priority
Watershed
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
Hydrologic
Soil
Groups
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
Priority
Charact.
Area
5.00
5.00
5.00
5.00
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
Maint.
Need
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
Struct.
Damage
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
Sw.
Catch/
Conv.
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
% Slope
2.50
2.50
5.00
7.50
7.50
10.00
5.00
10.00
5.00
10.00
5.00
5.00
7.50
7.50
5.00
7.50
5.00
Composite
Score
6.85
6.85
6.85
6.85
6.85
6.85
6.85
6.85
6.85
6.85
6.85
6.85
6.85
6.85
6.85
6.85
6.85
A-12
-------
Rank
Order
86.00
87.00
88.00
89.00
90.00
91.00
92.00
93.00
94.00
95.00
96.00
97.00
98.00
99.00
100.00
Parcel Code
104 263
102 133
104 218
069A025
104 264A
069A045
102 011E
102011Z
102 Oil
069A142
069 045
069 030
102 111
102 119
102 118
Publicly
Owned
Parcels
1.00
1.00
1.00
10.00
1.00
10.00
1.00
1.00
1.00
1.00
1.00
10.00
1.00
1.00
1.00
Impervious
Surface
2.50
2.50
2.50
5.00
2.50
5.00
5.00
5.00
5.00
10.00
2.50
2.50
5.00
7.50
7.50
Parcel
Size
10.00
7.50
10.00
10.00
7.50
7.50
2.50
7.50
10.00
2.50
10.00
10.00
7.50
7.50
7.50
Priority
Watershed
10.00
10.00
10.00
1.00
10.00
1.00
10.00
10.00
10.00
10.00
10.00
1.00
1.00
1.00
1.00
Hydrologic
Soil
Groups
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
7.50
Priority
Charact.
Area
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
5.00
7.50
7.50
7.50
7.50
7.50
Maint.
Need
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
Struct.
Damage
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
1.00
1.00
1.00
10.00
10.00
10.00
Sw.
Catch/
Conv.
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
10.00
% Slope
5.00
7.50
5.00
2.50
7.50
5.00
10.00
5.00
2.50
10.00
7.50
7.50
7.50
5.00
5.00
Composite
Score
6.85
6.85
6.85
6.85
6.85
6.85
6.85
6.85
6.85
6.70
6.70
6.70
6.70
6.70
6.70
A-13
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A-14
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Appendix B: Compendium of Indicators for Prioritizing Green Infrastructure
Opportunities
Depending on a community's planning and water quality and quantity goals, additional indicators,
beyond what were used in Clarkesville's prioritization, may be considered. The following indicators were
considered for the prioritization but were not directly relevant to Clarkesville's green infrastructure
goals. Other indicators, like threatened and endangered species, were not used because available
information indicated that these species did not exist within or immediately downstream of the city.
• Infiltration capacity- Natural rate of infiltration through soils: Soils with higher infiltration rates
present more promising opportunities for infiltration basins, bioretention, and other infiltration-
based practices.
• Proximity to existing stormwater facility - Distance between parcel and existing green
infrastructure or other stormwater management facility: Depending on the type and condition
of the facility, a shorter distance may present a greater or lesser opportunity for green
infrastructure. An existing structure, such as a stormwater pond, may provide a retrofit
opportunity that would improve the treatment and/or storage capabilities of the current
structure. However, if green infrastructure has already been implemented near a parcel, a city
may want to prioritize other areas that have more pressing needs.
• Land use - Specific type of land use or land cover that represents a priority for the city: While
impervious surface provided the best indicator of stormwater management needs for the City of
Clarkesville, other cities may have specific land uses that they are interested in targeting for
green infrastructure. For instance, if they wanted to prioritize commercial retrofits, than
commercial land use would be a useful indicator.
• Canopy cover - The extent of tree leaves and branches, either individually or within a group of
trees: Canopy cover can be used in different ways to support priorities. If a city is interested in
improving canopy cover of wildlife habitat, then it can be beneficial to target parcels adjacent to
large areas of existing canopy cover or to use green infrastructure to join to separate forest
areas, providing great habitat connectivity. Canopy cover can also help reduce the urban heat
island effect, and if this is a city priority, then green infrastructure could be prioritized in areas
with relatively little or no canopy cover.
• Stream reach length - Length of stream contained in parcel: this indicator can be most useful
when green infrastructure efforts are focused on riparian/stream preservation or restoration. By
prioritizing parcels with the greatest stream length, a city could optimize the size and benefit of
a project by working with a single landowner.
• Located within floodplain - Location with a defined flood hazard zone (e.g., FEMA 100-year
floodplain): green infrastructure opportunities within a floodplain are typically prioritized if the
city is interested in using wetlands restoration or similar strategies to treat and control
floodwaters. This indicator can also be used to identify current buildings or other uses that could
be relocated out of the floodplain and be replaced by green infrastructure.
• Protected species - Observed locations of protected species (e.g. federally threatened or
endangered): Locations known to support protected species can be used to prioritize nearby
green infrastructure that provides or augments habitat for these species. Green infrastructure
may also be prioritized where urban areas drain to stream reaches that support protected fish
and/or other protected aquatic species.
-------
• Right-of-way (ROW) evaluation - Area of government controlled right of way: In dense area
where retrofit opportunities are limited, cities can use available data on ROW dimensions to
locate areas with greater opportunities with ROWs for green infrastructure retrofits.
• Contaminated sites - Known records of actual or potential hazardous materials contamination:
where these data are available, cities can use these locations to screen out parcels that may
present constraints or additional costs related to contaminated soils or other hazardous
materials concerns.
• Space requirements - Minimum opportunity areas required for desired green infrastructure:
while green infrastructure ranges widely in size, a city may wish to pursue a specific type of
green infrastructure with a minimum space requirement. Using a combination of impervious
surface, parcel boundaries, and similar data, this indicator can be used to identify parcels that
have vacant land meeting the minimum space requirement.
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Appendix C: Design Recommendations
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C-2
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Legend
• Gl Site Location
Parcel of Interest
Figure C-l. Location map for Clarkesville Green Infrastructure Design Recommendations
C-3
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C«4
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Remove Asphalt
Pavement and
Replace with
Greenspace or
Overflow Parking
using Grass Pavers
Benefits
Peak Flow
Attenuation
Nutrient Uptake
Sediment
Removal
Beautification
Improved
Stream
Function
Legend
• Gl Site Location
Parcel of Interest
Site Location
Parcel Number
Date of Field Visit
Field Visit Personnel
Major Watershed
069A009
9/8/2014
HF, EB
Soque River
Latitude
Longitude
Street Address
Landowner
34° 36' 54.96" N
83° 31' 41.69" W
SR17
Habersham County
Project Narrative
This project is being presented with two options for consideration given the current site conditions and use
of the property. This parcel is the site of the former Habersham County Courthouse which has since moved
to a new location in Clarkesville. The former parking lot is beginning to show signs of disrepair and will
need to be replaced or removed in the near future. Option 1: During reconstruction of the parking lot,
bioretention should be considered as suggested in the concept drawing to treat stormwater runoff in lieu of
traditional drain systems. Option 2: Depending on parking needs, a large section of the parking lot may be
a good candidate for removal and turned into green space or overflow parking with grass pavers.
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Existing Parking Lot from SR 17
Example of Grass Pavers Being Installed
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Peak Flow
Attenuation
Nutrient Uptake
Sediment
Removal
Beautification
Improved
Stream
Function
S
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Site Location
Parcel Number N/A Latitude
Date of Field Visit 9/8/2014 Longitude
Field Visit Personnel HF, EB Street Address
Major Watershed Sweetgum Creek Landowner
Project Narrative
34° 36' 55.63" N
83° 31' 35.83" W
Washington St.
City of Clarkesville
This project is being presented in consideration of plans to extend streetscape improvements in the
downtown area of Clarkesville along Washington Street. During design of the new streetscape, green
street features such as curb extensions with rain gardens and tree box filters should be considered to
enhance beautification and provide hydrologic and water quality benefits. Other features that might be
considered include permeable pavers in parking areas and bioretention if ample space is provided during
the design. These projects are presented as options for phased implementation or as concepts for
consideration during coordination with other infrastructure improvements.
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Downtown Clarkesville
Downtown Clarkesville
How are green streets different
from traditional streets?
Green Street Features
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Example Green Street Features
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Route Stormwater from Grant St. into Bioretention Cells
• * »v. '
Disconnect Downspouts to \
Rain Gardens
Permeable
Pavers/Pavement
Benefits
Peak Flow
Attenuation
Nutrient Uptake
Sediment
Removal
Beautification
Improved
Stream
Function
S
S
S
S
Legend
• Gl Site Location
T Parcel of Interest
Site Location
Parcel Number
Date of Field Visit
Field Visit Personnel
Major Watershed
069A143
9/8/2014
HF, EB
Sweetgum Creek
Latitude
Longitude
Street Address
Landowner
34° 36'59.14" N
83° 31' 35.38" W
Grant St.
Private
Project Narrative
The main project being proposed for this area includes routing stormwater from Grant Street via curb cuts
into bioretention cells along the Grant Street border of the publicly owned parking lot at the corner of Grant
St. and Bridge St. Check dams will be incorporated into the bioretention area using hardscape structures to
miminize the slope and reduce the flow along the steep gradient. Additional project options include
disconnecting downspouts from buildings bordering the alleyway behind parcel 069A143 (Dreamers Ln.)
and treating the rooftop runoff from each building with rain gardens and replacing existing asphalt
pavement and concrete in the alleyway with permeable pavers or pervious pavement to enhance the green
alleyway concept. These projects are presented as options for phased implementation or as concepts for
consideration during coordination with other infrastructure improvements.
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Area along Grant St. to be converted to bioretention cells
Dreamers Ln. to be converted to green alleyway
Capped
Cleanout
Port
Check Gravel Splash Pad
Dam Underlain by Geotextile
2% Max Bed Slope
(5% Max Average Slope)
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Outlet to
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Example Bioretention Retrofit Cross Section
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Remove Asphalt
Pavement and
Replace with
Greenspace or
Overflow Parking
using Grass Pavers
Bioretention
Peak Flow
Attenuation
Nutrient Uptake
Sediment
Removal
Beautification
Improved
Stream
Function
S
S
S
S
Legend
• Gl Site Location
Parcel of Interest
Site Location
Parcel Number
Date of Field Visit
Field Visit Personnel
Major Watershed
069 032
9/8/2014
HF, EB
Sweetgum Creek
Latitude
Longitude
Street Address
Landowner
34° 37' 00.67" N
83° 31' 31.14" W
Grant Street
Habersham County
Project Narrative
This project is being presented with two options for consideration given the current site conditions and use
of the property. This parcel is the site of the former Habersham County Courthouse Annex Magistrate
Court which has since moved to a new location in Clarkesville. The parking lot appears to be larger than
needed for the buildings current use. Option 1: Bioretention should be considered as suggested in the
concept drawing to treat stormwater runoff from the rooftop and parking lot. Option 2: Depending on
parking needs, a large section of the parking lot may be a good candidate for removal and turned into green
space or overflow parking with grass pavers. These projects are presented as options for phased
implementation or as concepts for consideration during coordination with other infrastructure
improvements.
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Existing Parking Lot
Example of Grass Pavers Being Installed
overflow
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Rainwater
Harvesting for
Irrigation of Garden
and Grounds
Legend
• Gl Site Location
n Parcel of Interest
Site Location
Parcel Number
Date of Field Visit
Field Visit Personnel
Major Watershed
102 086
9/8/2014
HF, EB
Sweetgum Creek
Latitude
Longitude
Street Address
Landowner
34° 36' 55.78" N
83° 31' 30.10" W
458 Jefferson St.
City of Clarkesville
Project Narrative
An important asset to the City of Clarkesville, the Mauldin house serves as the City's welcome center and
offices for Downtown Development and Gardens and Grounds. The City acquired the property after the
death of Mary Mauldin, and completely refurbished the house and millinery shop and relocated the historic
Big Holly Cabin to the property. The project being proposed for this site includes the installation of a
rainwater harvesting system for irrigation of the Garden and Grounds. Although the roof top area of the
Mauldin house is relatively small for purposes other than irrigation, the proposed project should be
considered a great opportunity for green infrastructure education. Additional rainwater harvesting might be
feasible on the library property (Parcel 102 093) across the street from the Mauldin house.
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Garden and Grounds from the Corner of Jefferson St. and Green St.
Example of Rainwater Harvesting
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Diagram of Typical Rainwater Harvesting for Irrigation
-------
Relocate Police and
Fire Station and
Replace with Park and
Wet Detention Pond or
Park and Stormwater
Wetland
Sweetgum Creek
Legend
• Gl Site Location
H Parcel of Interest
Site Location
Parcel Number 102 087 Latitude
Date of Field Visit 9/8/2014 Longitude
Field Visit Personnel HF, EB Street Address
Major Watershed Sweetgum Creek Landowner
Project Narrative
34° 36' 57.20" N
83° 31' 28.69" W
Adams Street
City of Clarkesville
This project is being presented with two options in consideration of potential plans to relocate the existing
Clarkesville Police and Fire Stations to a new location within the City. The existing facilities have
experienced flooding from large storm events which is not surprising because they are located at the
confluence of the Stormwater system that forms the Sweetgum Creek headwaters. Because the parcel is
"on-line" and in an ideal location, it represents a unique opportunity within the small but densely developed
City to provide regional detention and treatment of Stormwater. Option 1: Relocate the Police and Fire
Stations to a new location within the City and replace with a City Park and Wet Detention Pond. Option 2:
Relocate the Police and Fire Stations to a new location within the City and replace with a City Park and
Stormwater Wetland.
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Stormwater Catch Basins at Intersection of Adams St and E Green St
Clarkesville Police and Fire Stations
Weir
Small pipe
or opening
Treatment volume
Sediments
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Example Wet Pond Cross Section
-------
Retrofit Existing Pond into
Stormwater Wetland
Legend
• Gl Site Location
Parcel of Interest
Site Location
Parcel Number
Date of Field Visit
Field Visit Personnel
Major Watershed
102 017
9/8/2014
HF, EB
Rocky Branch
Latitude
Longitude
Street Address
Landowner
34° 37' 10.75" N
83° 31' 19.28" W
515 Grant St.
Hawg Wild BBQ
Project Narrative
This project represents an opportunity to provide peak flow attenuation, water quality treatment, and
sediment removal for Rocky Branch before it enters the Soque River. The project includes retrofitting and
expanding an existing pond behind the Hawg Wild BBQ restaurant into a stormwater wetland. Water would
be diverted from Rocky Branch into the wetland during storm flows via a diversion structure/weir. Because
this project is located just upstream of the confluence with the Soque River, it has the potential to provide
significant improvements to impaired waters entering the Soque River. However, further investigation and
preliminary design calculations would be required to determine if the site has adequate capacity for
implementation.
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Rocky Branch Aggraded with Sediment Adjacent to Proposed Project
Portion of Existing Pond Adjacent to Rocky Branch
BLACK CH3K18ER«V.
SMOOTH SUMAC;
[OMfWN ELDERBERRY,
SWirtHGRASS,
LITTLE fllUESTEM,
BUT'ERfif WE£0
51IFP ASTER,
NEW f N6UNO ASTER
WOOL MASS.
SWAMP MILKWEED
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Example Wetland Retrofit Cross Section
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Dry Detention Retrofit
Legend
• Gl Site Location
] Parcel of Interest
Site Location
Parcel Number
Date of Field Visit
Field Visit Personnel
Major Watershed
102 119
9/8/2014
HF, EB
Soque River
Latitude
Longitude
Street Address
Landowner
34° 36' 41.87" N
83° 31' 21.61" W
Madison Street
ClarkesvilleUMC
Project Narrative
This project is being presented with two options should the community want to take advantage of a good
opportunity to treat stormwater on the grounds of the Clarkesville United Methodist Church. The site
currently has a low depression with a catchbasin that collects stormwater which then flows below Madison
Street via a stormwater pipe before draining into an open stormwater channel. Because the parcel is "on-
line" and the site is well suited for detention, this project represents a unique opportunity to treat
stormwater. Option 1: Retrofit existing low depression and catchbasin with features for dry detention.
Option 2: Expand Option 1 to include a second dry detention basin along Madison St. to increase storage
capacity.
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Dry Detention Retrofit Opportunity Location
Dry Detention Opportunity Location
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Example of a Dry Detention Basin During a Rain Event
-------
Remove Existing Asphalt
Pavement and Replace with
Permeable Pavers and/or
Permeable Pavement
Replace Gravel
Parking Area with
Grass Pavers
Legend
• Gl Site Location
~\ Parcel of Interest
Site Location
Parcel Number
Date of Field Visit
Field Visit Personnel
Major Watershed
104 041
9/8/2014
HF, EB
Soque River
Latitude
Longitude
Street Address
Landowner
34° 36' 28.49" N
83° 31'22.17" W
Stanford Mill Rd.
Habersham Co.
Project Narrative
This project is being presented with two options in consideration of potential plans to upgrade the parking
lot of the Habersham County Board of Education. The existing parking lot is showing signs of its age and
has fallen into disrepair along the western edge where the area is covered with gravel. If the parking lot is
going to be repaved and or rehabilitated, the following green infrastructure concepts should be considered.
Option 1: Replace gravel section with grass pavers or pervious pavement/pavers. Option 2: Replace paved
sections with pervious pavement/pavers as generally outlined in the concept drawing. These projects are
presented as options for phased implementation or as concepts for consideration during coordination with
other infrastructure improvements.
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Example of Grass Pavers Being Installed
Permeable
joint material
Open-graded
bedding course
Open-graded
base reservoir
Concrete pavers
Underdrairt
(as required)
Open-graded
subbase reservoir
Geotextile
(if required)
Unccmpacted
s-ubgrade soil
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Example of Permeable Pavers Cross Section
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Examples of Permeable Pavers/Pavement
Permeable Interlocking Concrete Pavers (PICP)
Concrete Grid Pavers
Porous Asphalt
Benefits*
Peak Flow
Attenuation
Nutrient Uptake
Sediment
Removal
Beautification
Improved
Stream
Function
"Benefits will vary
based on selected
practices.
Parcel Numbers
Date of Field Visit
Field Visit Personnel
Major Watershed
069A125,
069A131
N/A
N/A
Site Locations
Latitude
Longitude
Street Address
Sweetgum Creek Landowner
Project Narrative
34° 36' 55.71" N,
34° 36' 56.61" N
83° 31' 31.24" W,
83° 31' 29.64" W
1418 Washington St.,
129 E. Water St.
City of Clarkesville
In March 2014, a fire occurred in the east side of Clarkesville Square in downtown. Six buildings were
damaged, and two were ruled a total loss. The City has acquired these two properties and is currently
working on redevelopment plans. This project is presented with several options given the current site
conditions and use of the property. Option 1: Replace paved sections of the parking lot with permeable
pavers and/or permeable pavement. Option 2: Consider bioretention in parking lot to treat stormwater runoff
in lieu of traditional drain systems. Option 3: Install a green roof on one or both sites following
reconstruction to capture and treat stormwater, enhance aesthetics, and provide educational opportunities.
The insulation provided by green roofs can also result in energy cost savings.
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Example of Parking Lot Bioretention
1
Example Green Roof Installation
plants
growing medium
filter fabric
drainage/storage layer
insulation
waterproof membrane
protection board
roof deck
x
Example of Green Roof Functional Layers
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Rain Garden, Bioretention
or Wet Pond during
Development
Benefits*
Peak Flow
Attenuation
Nutrient Uptake
Sediment
Removal
Beautification
Improved
Stream
Function
"Benefits will vary
based on selected
practices.
Legend
~j Parcel of Interest
Site Location
Parcel Number
Date of Field Visit
Field Visit Personnel
Major Watershed
069A134
N/A
N/A
Sweetgum Creek
Latitude
Longitude
Street Address
Landowner
34° 36' 58.82" N
83° 31' 31.82" W
106 Bridge St.
City of Clarkesville
Project Narrative
This undeveloped parcel is located next to Sweetgum Creek and is downslope of the Clarkesville Square. If the City
plans to develop or sell the parcel for development, it would be advantageous to include green infrastructure in the
plans. Because the rear portion of the property is in the floodway of Sweetgum Creek, this area in particular could be
utilized to treat stormwater runoff from the proposed development while maximizing the developable land. Also,
depending on the existing drainage network, there may be an opportunity to divert water from Monroe Street and
Bridge Street into a treatment system such as bioretention at the rear of the property. Other possibilities to consider
during development include on-site retention concepts such as rainwater harvesting, green roofs, and permeable
pavements.
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Permeable
joint Tiaterisl
Open-graded
bedding course
Open-graded
base reservoir
Concrete pavers
Undefdram
(as required)
Open-graded
subbase reservoir
Geotextile
(if required)
Unccm parted
subgrade soil
Example of Permeable Pavers Cross Section
1
Example Green Roof Installation
overflow
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Example Bioretention Retrofit Cross Section
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C-16
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Appendix D: Code Review Checklist
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D-2
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Degree of Importance Key to Symbols:
• Essential
I Very important
Important
GOAL#1: MINI
IE EFFECTIVE OR CONNECTED IMPERVIOUS AREA
Objective: Minimize impervious area associated with streets.
Objective: Minimize impervious area associated with parking.
Objective: Minimize impervious area associated with driveways and sidewalks.
Objective: Clustering development.
Objective: Incorporate sustainable hydrology practices into urban redevelopment.
"YES" OR "NO."
"NO," OF IN
• Does the code definition of impervious area distinguish
between impervious area connected to the storm
drain system (effective impervious area) and
disconnected impervious area?
:i
No, ordinance refers to impervious area in general and does not
differentiate between effective and disconnected.
• For residential development, are the street pavement
widths allowed to be between 1 8 to 22 feet, with curb
pullouts for passing of large vehicles?
• Are travel lanes allowed to be from 1 2 to 1 0 feet (or
less), with curb pullouts for passing of large vehicles?
«
«
No, the minimum residential roadbed width allowed is 24 feet with
20 feet minimum pavement (curb and gutter subdivisions). Section 2819
(D)
No, see above.
D-3
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GOAL#I KEY QUESTIONS
• Are curb bumpouts/extensions allowed near
intersections and mid-block for traffic-calming and
bioretention opportunities?
• Is pervious paving allowed for on-street parking and
alleyways?
• Are grass swales or bioretention swales allowed
instead of curb and gutter or with curb cuts (where
slopes allow)?
• Are bioretention areas, swales, and other green
infrastructure techniques allowed to replace the
required "grass strip" between the sidewalk and curb?
• If there are cul-de-sacs, is the radius required to be 35
feet or less?
• If there are cul-de-sacs, are landscaped islands or
bioretention islands allowed or encouraged?
• Are site designs required to promote the most
efficient street layout to reduce overall street length?
DEGREE OF
IMPORTANCE
3
O
3
O
O
Q
REVIEWER COMMENTS
(INDICATE ORDINANCE FINDINGS "YES" OR "No." WHEN
"NO," NOTE SPECIFIC LOCATION OF BARRIER IN CODE)
No, curb bumpouts/extensions are not mentioned. Article XXVIII
Yes, permeable pavement is allowed for parking lots (Section 613), it is
not explicitly dis-allowed for on-street, alleyway parking. Section 2822
(J, K) state that pavement materials must be approved by the GADOT
Highway Division.
No, Section 2822 (Required Improvements, 1): "all streets with
subdivisions with 1.5 acre or less lots shall be paved with asphalt.. .and
provided with curbs and gutters constructed with either pre-cast
concrete curb, or integral concrete curb and gutter conforming to the
dimensions and standards in the adopted standard drawings."
Yes, while not specified, none of the Zoning Ordinance language
prohibits these practices.
No, turnarounds (cul-de-sacs) have minimum required radii ranging
from 40 to 50-feet depending on road type. Section 2819 (d)
Yes, allowed but not explicitly encouraged. See Section 2821 (d).
No, the zoning ordinance does not contain any language promoting
reduced or minimized street length.
• Is the minimum stall width for a standard parking space
9 ft. or less?
• Are parking stall lengths allowed to be 15 ft.?
•
•
Yes, a minimum of 160 square feet is required (width and length
unspecified), design flexible. Section 604
Yes, see above. However, the square footage requirement does not
allow for the 9 x 15-foot dimensions implied, which would equal 135
square feet, well under the minimum.
D-4
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GOAL#I KEY QUESTIONS
• Are parking lot drive aisles allowed to be 22 ft.?
• Are bioretention cells allowed in parking medians?
• Are consolidated travel lanes and on-street parking
allowed to create space for bioretention?
• Are pervious surfaces such as paver stones, porous
pavement, or grass pavers allowed for on-street
parking?
• For office buildings, is the required parking ratio 3.0
spaces per 1 ,000 sq.ft. of gross floor area or less?
• For commercial centers, is the required parking ratio 2
to 4.5 spaces per 1 ,000 sq.ft. of gross floor area or
less?
• Are proposed developments allowed to take
advantage of opportunities for shared parking?
• Are proposed developments allowed to have parking
stalls under the second floor podium?
DEGREE OF
IMPORTANCE
3
•
Q
3
3
3
Q
o
REVIEWER COMMENTS
(INDICATE ORDINANCE FINDINGS "YES" OR "No." WHEN
"NO," NOTE SPECIFIC LOCATION OF BARRIER IN CODE)
Yes, however, the design must provide a "sufficient" maneuvering isle
width subject to approval by the Zoning Administrator. Section 604
Yes, while not specified, none of the Zoning Ordinance language
prohibits these practices.
No, altering the required street width or number of lanes is not
specifically allowed for the purposes of bioretention.
Yes, Section 613 states that unused parking area reserved for future
parking be constructed of "well-known permeable and pervious
materials and design."
Yes, depending on building type. Office (general, professional) requires
1 space per 250 square feet of gross floor area. Article VI, Parking
(page 46)
Yes, depending on building type. Shopping Centers are required to have
1 space per 250 square feet of gross floor area. Article VI, Parking
(page 46)
Yes, Zoning Administrator authorizes reduction in total number of
required parking spaces when buildings share parking provided that
maximum parking time periods do not overlap and sufficient data is
provided. Section 610
Yes, while not specified, none of the Zoning Ordinance language
prohibits this practice.
• Do requirements for rooftop structures and materials
allow or encourage green roofs?
Yes, while not specifically encouraged, roofing materials are only
specified within the preservation overlay district requirements in
Section 2213. 3(B) (9)(d), which states that permitted roofing materials
are: tile, slate, stone, wood shake, textured composite shingles,
standard composite shingles (rubber roofing and Modified Bitumen
systems can be used on roofs that are not visible).
D-5
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GOAL#I KEY QUESTIONS
• Are buildings allowed to have bioretention areas,
swales, cisterns, and rain barrels near the foundation if
properly designed?
DEGREE OF
IMPORTANCE
REVIEWER COMMENTS
(INDICATE ORDINANCE FINDINGS "YES" OR "No." WHEN
"NO," NOTE SPECIFIC LOCATION OF BARRIER IN CODE)
Yes, while not specified, none of the Zoning Ordinance language
prohibits these practices.
• Are driveway standards 9 feet or less in width?
• Are shared driveways allowed?
• If sidewalks are required, are they required to be
designed to the narrowest allowable width (e.g, 4 ft.)?
• Are sidewalks allowed to be on one side of the street
only?
3
O
O
Q
NA, regulated by GADOT's "Regulations for Driveway and Encroachment
Control."
Yes, up to 4 lots or dwellings in a subdivision can share a driveway.
Section 2805.
No, the zoning ordinance does not contain requirements for sidewalks
or sidewalk width.
Yes, while not specified, none of the zoning ordinance language
prohibits this practice.
• Is redevelopment encouraged in lieu of greenfield
development through site performance standards?
• Is Conservation or Open Space Design an option?
• To encourage clustering and open space design, are
setbacks minimized (e.g., for residential lots that are
'/2-acre or less in size, is the front set back 20 feet or
less, the rear setback 25 feet or less, and the side
setback 8 feet or less?)
•
•
•
No, redevelopment is not specifically encouraged. However, the
planning commission encourages redevelopment within the
redevelopment character area on a site by site basis.
Yes, there is a conservation design option within the subdivision
regulations.
No, except for the downtown business district (DB), in which the
setbacks are zero, none of the front setbacks are less than 25 feet. A few
of the side or rear setbacks are relatively small. Article XXIII
D-6
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GOAL #I KEY QUESTIONS
DEGREE OF
IMPORTANCE
REVIEWER COMMENTS
(INDICATE ORDINANCE FINDINGS "YES" OR "No." WHEN
"NO," NOTE SPECIFIC LOCATION OF BARRIER IN CODE)
• Are site designs required to have development focused
on areas of lesser slopes and farther from
watercourses?
No, the ordinance does not require this; however, preservation of steep
slopes and stream buffers as open space is encouraged through the
conservation subdivision regulations. Section 2806 (I) Also, part of the
intent of the Tree Conservation Ordinance (Article XXIX) is to protect
stream buffers: "Existing trees in ... buffers shall be retained as much as
practical." The city's Sediment and Erosion Control code requires at
least a 25-foot undisturbed buffer along trout streams. Article II Division
1 Section 26-32 (4)
• Are policies effective in encouraging higher density
development to be centered around transportation
corridors?
Yes, per the zoning map, the business districts are focused around
transportation corridors.
D-7
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Objective: Minimize building footprint/envelope area.
Objective: Preserve topsoil structure.
Objective: Preserve sensitive wetlands.
Objective: Preserve sensitive soils.
Objective: Preserve sensitive stream buffers.
OR "NO."
"NO," OF IN
"jjiSQilI & Building Footprint
• Is disturbance of vegetated areas required to be
phased?
• Is disturbance of vegetated areas and riparian areas
required to be minimized?
• Are building envelopes required/encouraged to avoid
sensitive environmental areas such as riparian areas,
wetlands, high infiltration soils, and steep slopes?
*
••>
••>
No, the Zoning Ordinance does not contain any language regarding the
timing or phasing of land disturbance. Section 2910
Yes, part of the intent of the Tree Conservation Ordinance (Article
XXIX) is to retain existing vegetation to the extent possible, including
stream buffers: "Existing trees in ... buffers shall be retained as much
as practical."
Conservation Developments are required to minimize land disturbance
and removal of vegetation in residential development, as well as
promote interconnected greenways and green space. Section 2806
Yes, this is encouraged through the conservation subdivision design
option. Section 2806(1)
Wetlands
• Are site designs required to minimize hydrologic
alteration to existing wetlands?
*
No, this is not required, only encouraged through the conservation
subdivision design option. Section 2806(1)
D-8
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GOAL #2 KEY QUESTIONS
DEGREE OF
IMPORTANCE
COMMENTS
(INDICATE ORDINANCE FINDINGS "YES" OR "No." WHEN
"NO," NOTE SPECIFIC LOCATION OF BARRIER IN CODE)
• Are building footprints required/encouraged to avoid
highly erodible soils?
• Are building footprints required/encouraged to avoid
soils with high permeability (e.g., Hydrologic Soil
Group A and B)?
3
3
Section 2806. Conservation Developments are to avoid
"environmentally sensitive soils."
Section 2806. Conservation Developments are to avoid
"environmentally sensitive soils."
•-
• Is a 50- to 75-foot stream buffer required/encouraged
for new development?
• Are stream buffers for new development required to
remain in a natural state?
• Are site designs required to preserve existing runoff
pathways to adequately support existing wetlands?
• Is a 50-foot wetland buffer required/encouraged?
•
3
3
Q
Yes, at a minimum, these buffer widths are encouraged. Stream buffers
are defined on page 152 as "an undisturbed buffer on each side of the
stream, the minimum width of which is determined by the GAEPD or
by local ordinance or condition of zoning, whichever is greater." If the
development falls within a water supply watershed, GAEPD may
require 50 to 100-foot stream buffers.
Section 2806: Conservation Developments have a minimum 75-foot
buffer zone along perennial and intermittent streams.
No, the Zoning Ordinance does not require that stream buffers remain
in a natural state. The Tree Conservation Ordinance (Article XXIX)
requires that existing trees be retained to the extent practical but this
implies that the area surrounding the trees could be managed.
However, a natural, undisturbed state may be required by GAEPD if the
development is within a waters supply watershed. The conservation
subdivision design option encourages this. Section 2806(1)
No, this is not required. A topographic map of pre-development
drainage is required as part of the stormwater report. Section 2822 (E)
No, the Zoning Ordinance does not contain references to wetland
buffers.
D-9
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GOA1 #3: HARVEST RAINWATER TO ENHANCE POTABI E & NONPOTABI E WATER SUPPI Y
Objective: Through plumbing code provisions, enhance rainwater harvesting and water supply resources
Objective: Through the building and zoning code, allow the use of downspout disconnection/redirection, rain barrels, and above-and below-ground cisterns for
rainwater harvesting
COMMENTS
"YES" OR "NO." "NO,"
OF IN
;. • " '
• Are interior or exterior cisterns
allowed?
• Is a BMP maintenance plan
required?
• Is harvested rainwater allowed to
be used for nonpotable interior
uses such as toilet flushing?
• Are personal treatment systems
allowed to be used for potable
water supply?
«
0
Yes, Article VII, Section 100-1 (B) allows for stormwater capture and reuse.
No, but the owner of the property is responsible for all stormwater facility maintenance, and
the city can enforce this. Section 2822 (F)
NA, this is addressed by the state of Georgia plumbing code.
NA, this is addressed by the state of Georgia plumbing code.
• Can downspouts be disconnected
or redirected to discharge into a
rain barrel or yard?
• Are interior or exterior cisterns
allowed?
• Can rain barrels be placed within
standard zoning setback areas?
*
*
0
Yes, this is allowed per the state plumbing code for "one- and two-family dwellings, and
where approved." As stated above, the Zoning Ordinance allows for stormwater re-use.
htto://www. dca. state, aa. us/develooment/constructioncodes/oroarams/codeamendments. asp
Yes, the Zoning Ordinance does not prohibit rainwater harvesting facilities of any type.
Yes, see above.
D-IO
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GOAL #3 KEY QUESTIONS
• Do zoning and building provisions
allow cisterns to be placed on
rooftops to harvest rainwater?
• Is a BMP maintenance plan
required?
DEGREE OF
IMPORTANCE
3
•
COMMENTS
(INDICATE ORDINANCE FINDINGS "YES" OR "No." WHEN
SPECIFIC LOCATION OF BARRIER IN CODE)
"NO," NOTE
Yes, see above.
No, but the owner of the property is responsible for all stormwater facility
the city can enforce this. Section 2822 (F)
maintenance, and
D-ll
-------
Objective: Allow and encourage stormwater controls as multiple use in open space areas.
Objective: Allow and encourage stormwater controls as multiple use in landscaped areas.
DEGREE OF
COMMENTS
"YES" OR "NO."
"NO," OF IN
• Are bioretention areas allowed to be constructed in
the development's designated landscape areas, if
properly designed?
• Are bioretention areas given "credit" as landscape area
to count as a percent of the required landscaping?
• Are landscaping plans required to consider less water-
intensive, native vegetation?
• Do landscaping requirements allow plantings conducive
to bioretention, bioswales, rain gardens, and other LID
BMPs?
• Do tree planting requirements allow use of rain
gardens, tree boxes, and other LID BMPs?
• If irrigation is required, are weather-based irrigation
controls required?
«
«
«
*
«
*
Yes, for Conservation Developments. Section 2806 allows for
nonstructural stormwater management practices as well as "flexible
design" to protect stormwater and watershed integrity. For other
developments, nothing is explicitly prohibited.
Yes, while not specifically stated, landscaping requirements are based
on minimum number of trees, etc. and bioretention could be used to
meet these requirements. Section 2917
Yes, street and parking lot trees are required to be selected from the
native plant list. Section 2214 (Native Plant List) is intended to
"promote the planting of indigenous species of trees, shrubs and other
plants to reestablish and maintain the natural environment."
Yes, the native plant list contains appropriate species for LID BMPs.
Yes, although Section 2913 states that retention of existing healthy
trees is a priority over replacement with smaller trees, which should be
considered when proposing any kind of green space redevelopment.
No, the Zoning Ordinance does not require irrigation nor weather-
based irrigation controls. Article VII, Section 100-1
D-12
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GOAL #4 KEY QUESTIONS
DEGREE OF
IMPORTANCE
COMMENTS
(INDICATE ORDINANCE FINDINGS "YES" OR "No." WHEN
"NO," NOTE SPECIFIC LOCATION OF BARRIER IN CODE)
• Are there open space preservation requirements or
incentives?
• Is preserved open space required to be managed in a
natural condition?
• Are structural LID techniques such as constructed
wetlands, swales, and bioretention areas allowed to be
constructed in a development's designated open space,
if properly designed?
• Are structural LID techniques such as constructed
wetlands, swales, and bioretention areas given "credit"
as open space to count as a percent of the required
open space area, if properly designed?
• Does protection of sensitive, natural areas and habitat
qualify as credit for local open space dedication?
3
3
•
•
•
Yes, for Conservation Developments and Apartments. Article XXVIII
Section 2806 and Article XIII Section 1304 (4)
Yes, primary conservation areas, per the conservation development
option, are required to be maintained in a natural condition. Secondary
conservation areas, and open space required for apartment complexes,
do not have this requirement. Article XXVIII Section 2806 and Article
XIII Section 1304 (4)
Yes, while not specified in the ordinance, the city might allow structural
LID practices within designated open space on a site by site basis.
Yes, in terms of being part of the required open space for apartment
complexes.
Yes, under the conservation design option. Article XXVIII Section 2806
D-13
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GOAL #5: TO
Objective: Replicate the predevelopment hydrology of the site, to the extent practicable.
Objective: Maintain water quality functions of the watershed.
Objective: Minimize channel erosion impacts.
Objective: Minimize flooding impacts.
Objective: Inspect BMPs to ensure proper construction and design.
Objective: Long-term maintenance.
DEC REE OF
COMMENTS
"YES" OR "No."
"NO," OF IN
• Is stormwater required to be retained/infiltrated
onsite (through bioretention, natural areas, and swale
infiltration) where possible (e.g., Hydrologic Soil
Group A and B)?
• Do stormwater management practice standards and
sizing provide sufficient storage volume?
• Are water quality treatment performance standards
adequate?
• Are channel protection performance standards
adequate?
• Are flood control performance standards adequate?
• Are thresholds of applicability adequate (e.g. land
disturbance greater than 5,000 sq.ft.)?
*
*
«
«
*
«
No, the stormwater management sections do not require this. Section
2822 (D) through (F)
No, the Zoning Ordinance does not contain storage volume
performance standards.
No, the Zoning Ordinance does not contain water quality treatment
performance standards.
No, the Zoning Ordinance does not contain channel protection
performance standards.
See above.
Yes, Section 2822 (D)(2): New developments with 5,000 sq-ft or greater
of new impervious area require a stormwater management plan, or if
redevelopment is more than 50% of an existing site area. All
commercial or industrial development must have at least one storm
water management facility.
D-14
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GOAL #5 KEY QUESTIONS
• Are outfalls required to be stabilized to reduce
erosion?
DEGREE OF
IMPORTANCE
•
COMMENTS
(INDICATE ORDINANCE FINDINGS "YES" OR "No." WHEN
"NO," NOTE SPECIFIC LOCATION OF BARRIER IN CODE)
No, the Zoning Ordinance does not require this.
• Are inspections required during construction and
routinely after construction?
• Are inspectors required to be trained and certified?
•
Yes, during construction and once after completion. Section 2808 (9).
Yes, inspections must be made by the city's building inspector or a
third party certified building inspector. Article III, Section 301 and
throughout city code.
• Are maintenance agreements required?
• Is maintenance required to be performed by a certified
professional?
•
•
No, the Zoning Ordinance does not require maintenance agreements
for any type of green infrastructure.
No, the Zoning Ordinance does not contain any requirements for who
performs the maintenance.
• Is offsite mitigation required when on-site management
does not meet the performance criteria (unless there
is proof of no adverse impact)?
• Is offsite mitigation for forested area conservation
allowed in the same named watershed? Is the
replacement ratio at least 1:1?
• Is offsite mitigation for riparian area conservation
allowed in the same named watershed? Is the
replacement ratio at least 1:1?
• Is offsite mitigation for BMP retrofit allowed in the
same named watershed?
•
Cl
Cl
3
No, offsite mitigation is not explicitly required. Generally, the city
requires the developer to meet performance criteria on-site.
See above.
See above.
See above.
D-15
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GOAL #5 KEY QUESTIONS
DEGREE OF
IMPORTANCE
COMMENTS
(INDICATE ORDINANCE FINDINGS "YES" OR "No." WHEN
"NO," NOTE SPECIFIC LOCATION OF BARRIER IN CODE)
• Is nutrient banking or the equivalent land banking
allowed in the same named watershed? Is
redevelopment encouraged in lieu of greenfield
development?
No, nutrient banking is not mentioned and redevelopment is not
specifically encouraged in the ordinance. However, the planning
commission encourages redevelopment within the redevelopment
character area on a site by site basis.
D-16
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