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Upper Swannanoa River Watershed Plan i January 2016
Town of Black Mountain, N.C.
Table of Contents
Page
Acknowledgements ............................................................................................................................... iv
Key to Acronyms and Abbreviations ....................................................................................................... v
North Carolina 9‐Element Plan Checklist .............................................................................................. vii
Executive summary ................................................................................................................................. 1
Introduction ............................................................................................................................................ 5
Background and History ...................................................................................................................... 5
Why is the Upper Swannanoa River Impaired? .................................................................................... 9
Why Care? ........................................................................................................................................... 9
Environmental Factors .................................................................................................................... 9
Economic Factors .......................................................................................................................... 10
Social Factors ................................................................................................................................ 11
Watershed Partners and the Planning Process .................................................................................. 11
Previous Planning Efforts .............................................................................................................. 11
Stakeholder and Public Inputs ....................................................................................................... 13
Watershed Characterization ................................................................................................................. 15
Geographic Location and Attributes ................................................................................................. 15
Geography .................................................................................................................................... 15
Geology ........................................................................................................................................ 15
Climate ......................................................................................................................................... 15
Population and Land Use Characteristics .......................................................................................... 16
Population ..................................................................................................................................... 16
Land Use ....................................................................................................................................... 16
Natural Resources ............................................................................................................................. 18
Protected Lands ............................................................................................................................ 18
Important Plant and Animal Species ............................................................................................. 18
Ecology ............................................................................................................................................. 21
Water Quality ................................................................................................................................ 21
Benthic Communities .................................................................................................................... 24
Fish Communities ......................................................................................................................... 25
Planning Elements ................................................................................................................................ 27
Element A: Causes and Sources of Impairment ................................................................................ 27
Element B: Potential Projects and Management Measures .............................................................. 29
Watershed Management Goals ..................................................................................................... 29
Stormwater Impacts ..................................................................................................................... 29
Potential Stormwater Control Projects ......................................................................................... 30
Stormwater Control Management Measures ................................................................................ 51
Potential Stream Improvement Projects ....................................................................................... 59
Stream Improvement Management Measures .............................................................................. 64
Element C: Estimates of Pollutant Load Reductions ......................................................................... 68
Stormwater Control Measures ...................................................................................................... 68
Stream Improvements .................................................................................................................. 71
Element D: Technical and Financial Assistance Needs ...................................................................... 72
Upper Swannanoa River Watershed Plan ii January 2016
Town of Black Mountain, N.C.
Partners ........................................................................................................................................ 72
Technical Assistance ..................................................................................................................... 73
Management Measure Costs ......................................................................................................... 74
Stream Improvement Costs .......................................................................................................... 76
Funding Sources ............................................................................................................................. 77
Element E: Outreach and Education Strategy .................................................................................. 79
Action Plans .................................................................................................................................. 79
Implementation Schedule and Accomplishments Tracking ........................................................... 84
Element F: Schedule for Implementation ......................................................................................... 87
Stormwater Control Measures ...................................................................................................... 87
Stream Improvement Projects ...................................................................................................... 89
Element G: Measurable Milestones .................................................................................................. 91
Element H: Criteria of Pollutant Load Reduction Achievements ........................................................ 93
Stormwater Control Measures ...................................................................................................... 93
Stream Improvement Measures .................................................................................................... 93
Element I: Watershed Monitoring Plan ............................................................................................. 94
Water Chemistry ........................................................................................................................... 94
Ecological ...................................................................................................................................... 94
Stewardship Monitoring ................................................................................................................ 95
References ............................................................................................................................................ 97
Appendices ......................................................................................................................................... 103
Appendix A. Stormwater Assessment ............................................................................................. 103
Appendix B. Riparian Area Assessment ........................................................................................... 105
List of Figures
Page
Figure 1. Upper Swannanoa River Regional Overview ............................................................................. 7
Figure 2. Upper Swannanoa River Watershed Planning Area .................................................................. 8
Figure 3. Water Quality and Biological Sampling Sites .......................................................................... 22
Figure 4. Distribution of Potential Stormwater Control Projects ........................................................... 33
Figure 5. Conceptual Site Information Sheets ....................................................................................... 38
Figure 6. Rain Barrel and Cistern Setup ................................................................................................. 52
Figure 7. Dry Creek Beds in a Residential Setting .................................................................................. 52
Figure 8. Plant Uptake and Pollutant Removal Processes ..................................................................... 54
Figure 9. Bioretention Features in Residential and Commercial Applications ........................................ 55
Figure 10. Examples of Constructed Wetlands ...................................................................................... 56
Figure 11. Examples of Wet Ponds ........................................................................................................ 57
Figure 12. Examples of Extended Detention Retrofit Solutions ............................................................. 58
Figure 13. Potential Stream Improvement Projects ............................................................................... 61
Figure 14. Functions of Woody Riparian Vegetation .............................................................................. 64
Figure 15. Simple Riparian Revegetation Project Example .................................................................... 65
Figure 16. Stream Enhancement Project Example ................................................................................ 66
Figure 17. Stream Restoration Project Example .................................................................................... 67
List of Tables
Upper Swannanoa River Watershed Plan iii January 2016
Town of Black Mountain, N.C.
Page
Table 1. Upper Swannanoa River Watershed Stakeholder Group Membership ..................................... 13
Table 2. Land Use/Land Cover Characteristics and 2001/2011 Comparisons .......................................... 17
Table 3. Natural Heritage Program Natural Areas ................................................................................. 18
Table 4. Other Managed Lands ............................................................................................................. 18
Table 5. At‐Risk Animal and Plant Species ............................................................................................ 19
Table 6. Upper Swannanoa River VWIN Water Quality Data, 2012‐2015 ............................................... 23
Table 7. Benthic Macroinvertebrate Community Ratings by Site, 1987‐2015 ......................................... 24
Table 8. Swannanoa River Fish Community Ratings by Site, 1997‐2015 ................................................ 25
Table 9. Permitted Stormwater Dischargers ......................................................................................... 27
Table 10. Sources, Stressors, and Stress Indictors ................................................................................. 28
Table 11. Potential Stormwater Control Retrofit Projects ..................................................................... 34
Table 12. Stormwater Control Measure Characteristics ........................................................................ 37
Table 13. Potential Stream Improvement Projects ................................................................................ 63
Table 14. Recommended Native Plants for Use in Stream Restoration and Enhancement .................... 65
Table 15. Estimated Pollutant Load Reductions from Stormwater Control Measures. .......................... 69
Table 16. Estimated Sediment Reductions from Streambanks .............................................................. 71
Table 17. Potential Watershed Plan Implementation Partners .............................................................. 72
Table 18. Technical Assistance Needs to Implement Management Measures ....................................... 73
Table 19. Estimated Costs to Implement Non‐structural SCMs ............................................................. 74
Table 20. Estimated Costs to Implement Structural SCMs .................................................................... 75
Table 21. Estimated Costs to Implement Stream Improvement Projects .............................................. 76
Table 22. Potential Funding Sources for Watershed Improvement Projects ........................................... 77
Table 23. Outreach and Education Action Plans .................................................................................... 80
Table 24. Upper Swannanoa River Outreach and Education Implementation Schedule ........................ 84
Table 25. Stormwater Control Measures Implementation Schedule ..................................................... 88
Table 26 Implementation Schedule for Stream Improvement Projects ................................................. 89
Table 27. Measurable Milestones and Implementation Tracking for Stormwater
Control Measures ................................................................................................................. 91
Table 28. Measurable Milestones and Implementation Tracking for Stream
Improvement Projects ......................................................................................................... 91
Table 29. Measurable Milestones and Implementation Tracking for Monitoring
and Maintenance ................................................................................................................. 92
Table 30. SCM Pollutant Load Reduction Achievement Criteria ............................................................ 93
Table 31. Stream Improvement Pollutant Load Reduction Achievement Criteria .................................. 93
Table 32. Watershed Monitoring Plan ................................................................................................... 96
Upper Swannanoa River Watershed Plan iv January 2016
Town of Black Mountain, N.C.
Acknowledgements
We wish to thank the following individuals for their assistance:
Erica Anderson of the Land‐of‐Sky Regional Council of Government for her initiative in obtaining
matching money from the NCDWR 205(j) grant program.
Anne Marie Traylor of the Environmental Quality Institute provided water quality data, benthic
invertebrate community data, and reports from the EQI Volunteer Water Information Network (VWIN)
and Stream Monitoring Information Exchange (SMIE) programs
Amanda Bushon of the North Carolina Wildlife Resources Commission provided data on the
distribution of wild trout within the project area.
Jim Fox and Greg Dobson of the National Environmental Modeling and Analysis Center (NEMAC) for
guidance and assistance in qualitatively modeling of the effects of stormwater control measures on
receiving stream flow and frequency.
Upper Swannanoa River Watershed Plan v January 2016
Town of Black Mountain, N.C.
Key to Acronyms and Abbreviations
ACSP Agricultural Cost Share Program
CCDAP Community Conservation Assistance Program
CREP Conservation Reserve Enhancement Program
CRP Conservation Reserve Program
DEQ Department of Environmental Quality
EPA Environmental Protection Agency
EQI Environmental Quality Institute
EQIP Environmental Quality Incentives Program
HUC Hydrologic Unit Code
lb Pound(s)
LOSRCOG Land‐of‐Sky Regional Council of Government
MRA Mountain Retreat Association
MSI Municipal Sphere of Influence
NA Natural Area
NCDNCR North Carolina Department of Natural and Cultural Resources
NCDWR North Carolina Division of Water Resources (effective 2014)
NCDWQ North Carolina Division of Water Quality (pre‐2014)
NCEEP North Carolina Ecosystem Enhancement Program (renamed Division of Mitigation
Services in 2015)
NCIBI North Carolina Index of Biotic Integrity
NCNHP North Carolina Natural Heritage Program
NCSRI North Carolina Stream Restoration Institute
NCWRC North Carolina Wildlife Resources Commission
NEMAC National Environmental Modeling and Analysis Center
NPDES National Pollution Discharge Elimination System
PARTF Parks and Recreation Trust Fund
SCM Stormwater Control Measure
SVM Swannanoa Valley Museum
SMIE Stream Monitoring Information Exchange
SR Secondary Road
STEPL Spreadsheet Tool for Estimation of Pollutant Load
TBM Town of Black Mountain
TBD To Be Determined
TLW Targeted Local Watershed
TOM Town of Montreat
TMDL Total Maximum Daily Load
UNCA University of North Carolina at Asheville
USCB U.S. Census Bureau
USDA‐NRCS U.S. Department of Agriculture Natural Resource Conservation Service
USFWS U.S. Fish and Wildlife Service
USGS U.S. Geologic Survey
USRW Upper Swannanoa River Watershed
VWIN Volunteer Water Information Network
WMP Watershed Management Plan
Upper Swannanoa River Watershed Plan vi January 2016
Town of Black Mountain, N.C.
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Upper Swannanoa River Watershed Plan vii January 2016
Town of Black Mountain, N.C.
North Carolina 9‐Element Plan Checklist
Watershed Swannanoa River upstream of North Fork Swannanoa River
Applicant Name Equinox Environmental Consultation & Design, Inc. on behalf of the Town of Black Mountain
Contact Person/Title Josh Harrold – Town of Black Mountain Director of Planning and Development Services
or
Jim Borawa ‐ Equinox
Address 160 Midland Avenue
Black Mountain, NC 28711
or
37 Haywood Street, Suite 100
Asheville, NC 28801
Phone
Number/Email
828‐419‐9370; josh.harrold@townofblackmountain.org
Or
828‐253‐6856; jborawa@equinoxenvironmental.com
Date of Submittal December 15, 2015
What plans will
you be using to
document the 9
Elements
required for 319
funding? Please
provide a full
reference.
Name of Plan(s)
French Broad Basinwide
Water Quality Plan
French Broad River Basin
Restoration Priorities
2009
2014 Comprehensive
Plan Update for the
Town of Black
Mountain
Author/Developer
N.C. Division of Water
Quality
N.C. Ecosystem
Enhancement Program
Town of Black Mountain
Land‐of‐Sky Regional
Council of Government
Year
2011
2009
2014
Link/Location
http://portal.ncdenr.org/web/wq/ps/bpu/basin/frenchbroad/2011
http://portal.ncdenr.org/web/eep/rbrps/french‐broad
http://www.townofblackmountain.org/Town‐Government/Boards‐and‐
Commissions/Planning‐
Board?folderId=121&view=gridview&pageSize=10
Upper Swannanoa River Watershed Plan viii January 2016
Town of Black Mountain, N.C.
Upper Swannanoa River
Watershed
Management Plaan
Black Mountain
Wellhead Protection
Planning Project
Town of Black Mountain
Stormwater Master
Plan 2009
Comprehensive Plan
Alternatives for
Montreat, North
Carolina
The Upper Swannanoa
River is a targeted
local watershed for
stream restoration by
the NCDMS, but a
local watershed plan
has not been
developed.
Town of Black
Mountain/Equinox
Land‐of‐Sky Regional
Council of Government
Town of Black Mountain
McGill Associates, Inc.
Town of Montreat;
University of North
Carolina at Chapel Hill
N.C. Division of
Mitigation Services
2016
1995
2009
2003
N/A
http://portal.ncdenr.org/web/wq/ps/nps/319program/nc‐watershed‐
plans
Land‐of‐Sky Regional Council of Government. Asheville, North Carolina.
Not available on‐line.
Report not available on‐line; see Section 5.2 of the 2014 Master Plan
cited above.
http://www.townofmontreat.org/downloads/comp_plan/CompPlan1.pdf
See priorities planning map at:
http://portal.ncdenr.org/web/eep/priorities‐map
Once completed, please submit your checklist to Kim Nimmer at kimberly.nimmer@ncdenr.gov. DWR will conduct an internal review and notify you
when the plan has been determined to meet all of the 9 Elements and is eligible for Section 319 Grant implementation funding. As they are approved
they will be listed on DWR’s list of 319 watershed plans at htpp://portal.ncdenr.org/wegb/wq/s/nps/319program/nc‐watersehd‐plans. If you are
developing a plan that you are hoping to submit a 319 in the same year, please contact Kim Nimmer by email or by phone at (919)‐807‐6438. Your plan
will need to be submitted for approval at least 45 days prior to the 319 Grant application due date
Upper Swannanoa River Watershed Plan ix January 2016
Town of Black Mountain, N.C.
1. Identification of the Causes and
Sources Checklist
Yes No Notes Identify location of information (include link or
attach plan and identify section and page number)
REQUIRED (This box(es) below must be checked Yes in order to be eligible as a 9 Element plan)
Does this plan identify stressors and
sources in the watershed? X Element A, Page 22
OPTIONAL (Supplemental and/or supporting information)
Was a GIS desktop analysis
performed?
X
Potential stormwater retrofit sites
and stream riparian areas in need of
improvement were assessed and
modeled in GIS using aerial photos
and land use data
Element B, Pages 25, 26, and 53
Has existing water quality or
biological data been reviewed?
• Ambient water quality data
• USGS data
• Other?
X
NCDWR benthic macroinvertebrate
survey data
VWIN water quality data
SMIE benthic invertebrate survey
data
Watershed Characterization
Water Quality, Page 18
Benthic Communities, Page 21
Fish Communities, Page 22
Does the plan(s) identify any water
quality impairments in this
watershed (303(d) list)?
X
Review of available data shows no
exceedances of state standards
Watershed Characterization
Water Quality, Page 18
Has a field assessment been
conducted?
• CWP (Center for Watershed
Protection) Method
• EEP (Ecosystem Enhancement
Program) Manual
• Other?
X
Field assessment of potential
stormwater retrofits sites was
conducted following Equinox
established procedures.
Element B Management Measures
Stormwater, Page 26 and Appendix A
Does the plan indicate if a TMDL has
been developed for this watershed? X A TMDL has not been developed for
this watershed.
Introduction, Page 6
Does the plan(s) include a map that
shows where stressors and sources
are concentrated? X
Potential project site locations are
identified
Element B Management Measures
Potential Stormwater Control Projects, Figure 4 on
Page 28
Potential Stream Improvement Projects, Figure 13
on Page 55
Upper Swannanoa River Watershed Plan x January 2016
Town of Black Mountain, N.C.
2. Description of the NPS
Management Measures Checklist
Yes No Notes Identify location of information (include link or
attach plan and identify section and page number)
REQUIRED (This box(es) below must be checked Yes in order to be eligible as a 9 Element plan)
Does the plan(s) identify
management measures that address
the stressors and sources identified
in Element 1? (note prioritization of
projects would be considered to meet this
element)
X
Management measures applicable to
this plan are described; a list of
potential projects is presented,
including priority by expected time
frame for implementation.
Element B Management Measures
Stormwater, Page 46
Stream Improvement, Page 57
3. Estimate of the load reductions
expected for the management
measures
Yes No Notes Identify location of information (include link or
attach plan and identify section and page number)
REQUIRED (This box(es) below must be checked Yes in order to be eligible as a 9 Element plan)
Have potential indicators been
identified for each management
measure to determine success?
X
Indicators identified for each project
type. Within project type indicators
apply across management measures
Element H Pollutant Load Reduction Achievements
Stormwater, Page 83
Stream Improvement, Page 83
Has it been roughly quantified how
much each management measure
will reduce one or more parameters
identified in Element 1?
X
Reductions of TSS, N, P, and Zn are
calculated for stormwater measures
Reductions in sediment estimated for
stream improvement measures.
Element X Estimate of Pollutant Load Reductions
Stormwater, Table 15 Page 61
Stream Improvement, Table 16 Page 63
OPTIONAL (Supplemental and/or supporting information)
Has a water quality, watershed or
lake response model been
developed for this watershed?
X
Upper Swannanoa River Watershed Plan xi January 2016
Town of Black Mountain, N.C.
4. Estimate of the technical and
financial assistance needed
Yes No Notes Identify location of information (include link or
attach plan and identify section and page number)
REQUIRED (This box(es) below must be checked Yes in order to be eligible as a 9 Element plan)
Have the potential costs associated
with management activities listed in
the plan(s) been identified? X
Estimates for management measures
and outreach and education
activities have been estimated.
Element D Technical and Financial Assistance Needs
Stormwater Management Measures Costs, Table 19
Page 55; Table 20 Page 67
Element E – Outreach and Education Plans, Pages 71‐
74
Has the technical assistance that may
be required to help with design,
construction, implementation and
monitoring of management
strategies listed in the plan(s) been
identified?
X
Type of technical assistance and
sources of assistance for each
management action are listed
Element D Technical and Financial Assistance Needs
Table 18 Page 65
OPTIONAL (Supplemental and/or supporting information)
Have potential partners and funding
sources to assist with
implementation of the watershed
plan(s) been identified and/or
contacted?
X
Potential partners have been
identified; some have been
contacted or were part of the
stakeholder group.
Element D Technical and Financial Assistance Needs
Table 17 Page 64
Have potential partners and funding
sources to assist in the maintenance
and/or monitoring following
completion been identified?
X
Monitoring Partners identified;
management measure maintenance
entity to be determined during
project development
Element D Technical and Financial Assistance Needs
Table 17 Page 64
Element I Watershed Monitoring Plan, Page 84
Upper Swannanoa River Watershed Plan xii January 2016
Town of Black Mountain, N.C.
5. Information/Education
component
Yes No Notes Identify location of information (include link or
attach plan and identify section and page number)
REQUIRED (This box(es) below must be checked Yes in order to be eligible as a 9 Element plan)
Have a range of information and
education options been identified in
the watershed plan? X
Four Categories Addressed ‐ General
outreach, Local Government
Practices and Program, Outreach to
the Business Community, Public
Stormwater Management Practices
Element E Outreach and Education
Action Plans, Pages 71‐74
OPTIONAL (Supplemental and/or supporting information)
Have resource agencies that can be
integrated into the watershed
planning process been identified
and/or contacted?
X
Some participated in stakeholder
group meetings; others listed as
potential partners; will be asked to
participate based on their area of
expertise
Element E Outreach and Education
Potential Partners, Page 64
6. Schedule for implementing
management measures
Yes No Notes Identify location of information (include link or
attach plan and identify section and page number)
REQUIRED (This box(es) below must be checked Yes in order to be eligible as a 9 Element plan)
Have the tasks and activities that are
related to the implementation and
monitoring of management
recommendations been identified?
X
Standard project development
activity list compiled; list of items for
which costs cannot be predicted are
also included
Element D Technical and Financial Assistance Needs
Management Measures Costs, Pages 65‐66
Has it been determined if these tasks
and activities are short‐term,
medium, or long‐term in nature (note:
prioritization of projects is acceptable for
meeting this element)?
X
Planned timeframe for stormwater
control measures developed; stream
improvement projects are based on
linear footage of stream to be
addressed, not individual project.
Element F Schedule for Implementation
Stormwater Control Measures, Table 24 Page 78
Stream Improvement Projects, Table 25 Page 79
7. Description of interim,
measurable milestones
Yes No Notes Identify location of information (include link or
attach plan and identify section and page number)
REQUIRED (This box(es) below must be checked Yes in order to be eligible as a 9 Element plan)
Have interim, measurable milestones
(things that you can track) that can
help determine if management
measures (in Element 2) are being
implemented been identified?
X
Measureable milestones and
accomplishment tracking tables are
presented.
Element G – Measurable Milestones
Tables 26‐28 Pages 81‐83
Upper Swannanoa River Watershed Plan xiii January 2016
Town of Black Mountain, N.C.
8. Criteria that can be used to
determine if loading reductions are
being achieved
Yes No Notes Identify location of information (include link or
attach plan and identify section and page number)
REQUIRED (This box(es) below must be checked Yes in order to be eligible as a 9 Element plan)
Have criteria and/or indicators that
can be used to determine if
management strategies and activities
listed in the plan(s) are being
effective been identified?
X
Watershed response indicators are
identified and presented.
Element H – Criteria of Pollutant Load Reduction
Achievements
Stormwater, Table 29 Page 83
Stream Improvement, Table 30 Page 83
9. Monitoring Yes No Notes Identify location of information (include link or
attach plan and identify section and page number)
REQUIRED (This box(es) below must be checked Yes in order to be eligible as a 9 Element plan)
Has a monitoring plan that includes
each of the criteria and/or indicators
identified in Element 8 been
developed?
X
Implementation tracking tables and
water quality/biological sampling
tables will document watershed
improvement achievements
Element G Measureable Milestones
Implementation Tracking Tables 26‐28 Pages 81‐82
Element I – Watershed Monitoring Program, page XX
OPTIONAL (Supplemental and/or supporting information)
Are there plans for conducting water
quality monitoring?
• Intensive/On‐going
• Field kits? X
Ongoing monthly sampling to be
conducted by the Environmental
Quality Institute Volunteer Water
Information Network
Requests for benthic
macroinvertebrate and fish sampling
will be made for years 1, 5, and 10.
Element I – Watershed Monitoring Plan
Table 31 Page 86
If water quality monitoring is
expected to be conducted, have you
contacted NCDWR? X
NCDWR participated in the
stakeholder group and is aware of
the VWIN program; no NCDWR
funded sampling is planned at this
time.
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Upper Swannanoa River Watershed Plan 1 January 2016
Town of Black Mountain, N.C.
EXECUTIVE SUMMARY
The Upper Swannanoa River Watershed (USRW), delineated as the seven mile portion of the
Swannanoa River and tributaries upstream of its confluence with the North Fork Swannanoa River was
placed on North Carolina’s 303(d) impaired waters list in 2006 because of a degraded benthic
macroinvertebrate community. Recent state planning documents for the French Broad River basin
identified stormwater as a major cause of degraded conditions of the Swannanoa River. To address the
impacts of stormwater runoff, the Town of Black Mountain (TBM) partnered with the Land‐of‐Sky
Regional Council of Governments to obtain funding for development of an EPA compliant 9‐element
watershed management plan (WMP).
This document represents the culmination of a collaborative planning effort led by the TBM. The main
objective of the planning process was to identify actions necessary to address existing stormwater
runoff problems and lead to the removal of the Swannanoa River from the impaired waters list. It will
complement the TBM’s current efforts to upgrade its stormwater infrastructure and manage future
construction under phase II stormwater regulations. Approval of this WMP will give the TBM access to
grant funds to construct stormwater control features and improve riparian vegetation as well as
implement an outreach and education program. Funding for such projects is available through the EPA
319(h) non‐point source pollution abatement program and administered by the North Carolina Division
of Water Resources.
Historically, the USRW was an Indian hunting ground and it remained isolated until after the
Revolutionary War when the first road into the area was constructed; a rail line was completed in 1879.
Today the towns of Black Mountain and Montreat, which make up much of the watershed, are thriving
communities that are supported by tourism, religious retreats, outdoor recreation, and second home
development. While much of the land at higher elevations is forested, flatter land at lower elevations
has become urbanized. Although heavy industry and agriculture no long have a major presence in the
watershed, commercial, institutional, and residential development associated with urbanization has
accelerated. This development has significantly increased the amount of impervious surface, be it from
buildings, roads, or parking lots. This has decreased the ability of the watershed to absorb stormwater.
The removal of forest cover and the conversion of other land to open space consisting of turf and lawns
also has contributed to the stormwater runoff problems. Stormwater runoff from these less pervious
surfaces has increased the volume, peak flows, and peak flow frequencies of the USRW. This has
resulted in the erosion of stream banks and the degradation of aquatic habitat. In addition, the loss of
woody riparian vegetation associated with changes in land use adjacent to streams have contributed to
streambank instability and increased erosion.
While development in the USRW has caused degradation of streams, it is a very environmentally
conscious community. The residents value the benefits of clean water and ecologically functioning
waterways. They also recognize that not only is a good environment beneficial to their health but it
also serves as the basis for economic prosperity and social activities such as fishing, boating, crafts, and
nature watching.
This watershed management plan (WMP) was developed with input from a stakeholder group whose
members represent local and state government, educational institutions, and a conservation
organization. They played an important role in developing the outreach and education program and
Upper Swannanoa River Watershed Plan 2 January 2016
Town of Black Mountain, N.C.
aided in the identification of potential stormwater retrofit sites. They also participated in a consensus
modeling technique to determine the implementation schedule for stormwater projects.
Geographically, the USRW is located in eastern Buncombe County and drains 15 miles to the west
where it joins the French Broad River. The watershed has three natural areas designated by the North
Carolina Natural Heritage program. Some or all of these natural areas are contained on the 8,000 acres
of land in the watershed that are managed for the conservation of natural resources. Two rare plants,
four rare animals, and one rare natural community likely occur within the watershed. These
occurrences along with a number of rare upland plants, animals, and natural communities reflect the
biological diversity of the area.
Ecologically, the USRW water quality is good, having recovered from the clear‐cut logging practices of
the early 20th century. No pollutants are known to exceed state standards. The State of North Carolina
has rated benthic communities in the upper part of the watershed as Good‐Fair to Excellent. Lower in
the watershed, however, those ratings decline to Fair and, as a consequence, the watershed is
considered impaired. The condition of the fish community is not known, although wild trout have been
documented in the mainstem Swannanoa River as far downstream as Black Mountain Recreational
Park.
The effects of increased stormwater runoff cause increased peak flows, increased peak flow
frequencies, and shortened peak flow duration. These changes in stream flow have resulted in
increased streambank and channel scour, streambank instability, and, where woody riparian vegetation
is sparse or lacking, increased water temperatures.
Potential stormwater retrofit and stream improvement sites were identified using a combination of GIS
data, aerial photo interpretation, and field assessments (stormwater only). Once those sites were
identified, appropriate management actions for the projects were selected.
Of the 31 potential stormwater retrofit sites identified, 21 were found to be feasible. All but seven sites
are located in or near Black Mountain’s town center. Conceptual plans for17 sites indicate it may be
possible to construct 11 bioretention features, four wetland features, and one extended detention
feature. There is also the potential to install one cistern and one underground detention chamber.
Private landowners also are encouraged to install non‐structural features such as rain barrels and
backyard raingardens. The WMP includes descriptions and examples of each type of feature
recommended.
The SIMPLE model was used to estimate pollutant reductions at the 21 proposed stormwater retrofit
sites. Outputs from that model indicate annual reductions of 1.9 tons of suspended sediment, 14
pounds of phosphorus, 103 pounds of nitrogen, and 8 pounds of zinc. The stormwater features will also
act to moderate runoff volumes, peak flows, and peak flow frequencies as they are designed to handle a
1‐year 24‐hour storm event.
Rain barrel and raingarden installations are estimated to cost from less than $100 to about $400 per
unit. Estimated costs to design and construct structural stormwater control features range from $4.07
to $20.93 per square foot of treatment. Individual site costs are estimated to range from $11,600 to
$615,825. These costs do not include land acquisition, utility relocations, street modifications, or legal
fees, if necessary.
Sixteen potential stream improvement sites covering an estimated 31,000 feet of stream channel were
identified with almost 19,000 feet of that occurring in the Tomahawk Branch subwatershed. The
remaining 12,000 feet are scattered among 10 sites across the remainder of the USRW. Three
Upper Swannanoa River Watershed Plan 3 January 2016
Town of Black Mountain, N.C.
management action options, riparian revegetation, stream enhancement, and stream restoration are
recommended. Assessment of parcel ownership and on‐site conditions will be necessary to determine
which management action will be necessary to improve stream channel and riparian vegetation.
Although no landowner outreach has been conducted, several sites in the Tomahawk Branch
subwatershed are on public land. It is recommended that those sites be pursued first as it is usually
easier to gain approval from public agencies to implement stream improvement projects.
The STEPL model was used to estimate the reduction in sediment originating from streambanks
lacking woody riparian vegetation. Implementation of all 16 projects would achieve an annual
reduction of an estimated 1,014 tons of sediment to the USRW; 730 tons of that could be achieved by
implementing projects in the Tomahawk Branch subwatershed alone.
Generalized costs for each of the stream improvement project types are: riparian revegetation ‐ $80‐
100 per linear foot; channel enhancement ‐ $100‐$200 per linear foot; channel restoration ‐ $200+ per
linear foot. As with SCMs, these costs do not include land acquisition, utility relocation, road
modification, or legal fees, if necessary.
Stakeholder group input provided the basis for the outreach and education strategy. It is aimed at
informing the public about the work proposed in this plan and environmental education in general. The
outreach and education strategy has four components – programmatic outreach, local government
practices and programs, outreach to the business community, and public stormwater management
practices. Key elements of this strategy include development of an active watershed group to guide
implementation of the outreach action plan, environmental education of youth, education of elected
officials, engagement of the business community to help with WMP implementation, and utilization of
high visibility stormwater features to demonstrate how they work and the environmental benefits they
provide.
Stormwater retrofit and stream improvement projects proposed in the WMP are scheduled for
implementation over the 10‐year life of the plan. For planning purposes projects were assigned to one
of three implementation periods: short‐term – 1‐3 years; mid‐term – 4‐7 years; long‐term – 8‐10 years.
Actual implementation will be opportunity driven primarily by landowner willingness to participate and
the ability to acquire funding for individual projects. A project tracking and accomplishments table is
included in the WMP so as to determine how well the plan is being implemented.
Potential funding sources are identified and include state, federal, and private entities. Technical
assistance for the various types of projects are also described and include local, state, and federal
agencies as well as private businesses.
Last, but most importantly, a watershed monitoring plan was prepared. It recommends water
chemistry and benthic macroinvertebrate monitoring by local volunteers to track trends in watershed
conditions. It also recommends that the North Carolina Division of Water Resources be requested to
sample the fish and benthic macroinvertebrate community at five year intervals as a way to determine
whether or not the USRW conditions are such that it is meeting its uses and can be removed from North
Carolina’s 303(d) impaired waters list.
Upper Swannanoa River Watershed Plan 4 January 2016
Town of Black Mountain, N.C.
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Upper Swannanoa River Watershed Plan 5 January 2016
Town of Black Mountain, N.C.
INTRODUCTION
Background and History
The portion of the Swannanoa River watershed in the Black Mountain area was originally known as
Grey Eagle by the Cherokee and Catawba Indians (TBM 2015). Based on archaeological finds, the
Swannanoa River valley has been inhabited for at least 12,000 years and served as hunting grounds for
these tribes (SVM 2015). Due to the steepness of the slopes to the east the area was insulated from
colonization until the middle 1700’s when settlers began to arrive. After the revolutionary war,
Europeans of Scot‐Irish, German, and English descent began arriving, some bringing African slaves with
them. Development of the Swannanoa River valley accelerated with the building of a road through the
area in 1850 (Wikipedia® 2015) and the coming of the railroad in 1879. The improved access brought
prosperity as tourists and land speculators arrived and farmers began to export livestock and crops.
The Town of Black Mountain, the principal municipality in the Upper Swannanoa
River Watershed (USRW) was incorporated in 1893 (Figure 1). The area known today
as Montreat, officially incorporated as a township in 1967 (Wikipedia 2015), was
originally organized in 1897 as the Mountain Retreat Association (TOM 2015). The
name was shortened to Montreat the same year. Into the early 1900s the upper
Swannanoa River valley became a center for major religious retreat centers that
included not only Montreat but also Ridgecrest and the YMCA Blue Ridge Assembly
among others.
Early settlement of the Swannanoa River valley was dominated by agricultural activities. With the
coming of the railroad and need for timber in the industrial north, loggers clear‐cut the mountainsides
during the 1910s and exposed mountainside soils. The exposed the soils were then subject to erosion,
particularly that associated with the flood of 1916 that hit the Southern Appalachian Mountains.
Between Asheville and Old Fort about 30 miles of railroad track were washed away or otherwise
damaged. Heavy rains caused landslides that buried some tracks with up to 28 feet of soil (Williams
2013).
Today farmland has all but disappeared in the portion of the USRW encompassing Black Mountain and
Montreat; manufacturing jobs, too have decreased significantly. While many of the
religious retreats have survived, the area is now home to residential housing
developments for workers commuting to Asheville and other parts of the county as
well as seasonal residents. A major portion of the local economy is based on tourism.
Montreat Normal School, now Montreat College, which opened in 1916, is located
within the watershed.
The transition from an agricultural/industrial‐based economy to one dominated by residential and
tourism‐based growth has brought with it changes in the impacts to the ecology of the watershed.
Agricultural runoff (sediment, nutrients, and fecal coliform bacteria) and industrial discharges are no
longer a major factor influencing water and habitat quality of the USRW. Despite this change, the
upper Swannanoa River is on North Carolina’s 303(d) list of impaired waters.
Upper Swannanoa River Watershed Plan 6 January 2016
Town of Black Mountain, N.C.
For the most part, headwater streams of the Upper Swannanoa River run much clearer. Much of the
land surrounding those streams, damaged by past
logging, is once again forested. During the mid‐
1900s some of those previous impacted streams
were impounded to serve as drinking water supplies
or provide recreation (Brown and Caldwell 2010a).
The North Carolina Natural Heritage Program has
also given some lands in the watershed a Moderate
or High ratings as natural areas; some of those lands
are protected by conservation easements or as
registered heritage areas (NCNHP 2015a).
This watershed management planning (WMP)
document focuses on the developed portions of the
Swannanoa River watershed upstream of its confluence with the North Fork Swannanoa River (Figure
2). This portion of the watershed has been impacted by urban development that contributes to water
quality and aquatic habitat degradation. Because of this development, almost the entire area is now
subject to Environmental Protection Agency Phase II stormwater control regulations that are either
under individual National Pollution Discharge Elimination (NPDES) permits or fall within the
surrounding MSI (municipal sphere of impacts) area.
While the new regulations will influence stormwater impacts for future development projects, it does
not address existing problems. As a result, the Town of Black Mountain, in cooperation with its
partners, felt that a locally inspired WMP would be the most effective way to address existing
problems. The objective of this WMP is to identify potential projects that address watershed
impairment associated primarily with stormwater runoff and associated sediment. It will include
watershed improvement measures that can be taken to improve watershed conditions to the point
where the upper Swannanoa River can be removed from the 303(d) impaired waters list. The content of
this watershed plan will address the Environmental Protection Agency’s (EPA) required 9‐elements that
will make its sponsor, the Town of Black Mountain, eligible to apply for funding through EPA’s 319(h)
non‐point source grant program that is administered through the North Carolina Department of
Environmental (DEQ) Division of Water Resources (NCDWR).
Upper Swannanoa River Watershed Plan 7 January 2016
Town of Black Mountain, N.C.
Figure 1. Upper Swannanoa River Regional Overview
Upper Swannanoa River Watershed Plan 8 January 2016
Town of Black Mountain, N.C.
Figure 2. Upper Swannanoa River Watershed Planning Area
Upper Swannanoa River Watershed Plan 9 January 2016
Town of Black Mountain, N.C.
Why is the Upper Swannanoa River Impaired?
The seven mile reach of the Swannanoa River upstream of its confluence with the North Fork
Swannanoa River has been on North Carolina’s 303(d) list of impaired waters since 2006 (Figure 2;
NCDWR 2014a). This portion of the Swannanoa River is not fully supporting its uses that include
maintaining balanced fish and benthic macroinvertebrate communities. Those communities should be
comprised of diverse indigenous species at population levels considered at least Good‐Fair when
compared to reference streams. Based on 2002‐2003 benthic invertebrate community assessments,
the upper Swannanoa River was rated as Fair (NCDWQ 2008, 2014b).
Under the integrated reporting classification, the upper Swannanoa River has been designated as
Category 5, which means that available data indicates that at least one use is not being met and that a
total maximum daily load (TMDL) must be calculated. A TMDL is a calculation of the maximum amount
of pollutant that a waterbody can receive and still meet water quality standards. It is generally applied
to pollutants with identifiable sources that can be readily remediated. Since that is not the case in the
USRW, a TMDL has not been developed. In the USRW the biological community is being degraded
primarily due to the impacts of stormwater runoff that include scouring of the stream channel and
stream banks. Under this plan, the Town of Black Mountain has volunteered to sponsor the
development of this watershed management plan and to implement watershed improvement projects
that are expected to result in improvement of the biological community.
Why Care?
Why should citizens living, working, or recreating in the USRW concern themselves with the conditions
of the river and its tributaries? Because there are a number of environmental, economic, and social
factors that relate stream health to community health.
Environmental Factors
Streams are valuable resources that provide a variety of ecosystem services. Ecosystem services
are natural processes that benefit the environment
and, in turn, benefit people. A hydrologically
functioning watershed provides flood control, which
reduces property loss and damage during flood
events. A healthy stream provides habitat for a
variety of plants, fish, amphibians, and insects that
prey on pests such as mosquitoes, black flies, and
midges. A functioning aquatic ecosystem also
provides surface water filtration, purification, and
pollutant processing.
Fact – Due to the terrain, stormwater in
mountainous areas have a greater
propensity to erode soils and cause more
widespread flooding than in non‐
mountainous regions.
Upper Swannanoa River Watershed Plan 10 January 2016
Town of Black Mountain, N.C.
How the land we live on is utilized directly influences the health of streams. As it stands, while
much of the land in the headwaters of the upper Swannanoa River is forested, stream banks
along the less steep areas are urbanized and have less than ideal wooded riparian areas. This has
led to increased stormwater runoff volumes that are eroding
sediment deposited on stream banks during the early 20th
century. As these stream banks are eroded sediment yields
stay unnaturally high and degrade instream habitats by filling
in riffles and pools with sand and fine sediment. Erosion of
stream banks also threatens to damage adjacent property. As
a result, the diversity of plants and animals living in the upper
Swannanoa River is not as healthy as it could be.
Economic Factors
The condition of the USRW has significant economic implications for the towns of Black
Mountain and Montreat as well as the surrounding portion of eastern Buncombe County.
Tourism and outdoor recreation are important contributors to the local economy. Buncombe
County ranked first in western North Carolina in total tourism expenditures ($662 million;
NEMAC 2013). Add to that the number of church affiliated summer camps providing outdoor
recreation and second home developments established in recent years and the importance of
maintaining the environment of the watershed becomes clear. This development has helped
offset and replace lost manufacturing jobs and wages. Outdoor recreation in North Carolina,
exclusive of fishing, hunting, and wildlife viewing, is estimated to generate $19.2 billion in
consumer spending (OIA 2011/2012).
Financial resources are required to mitigate the effects of poor water quality. Property damage
due to unstable stream banks can be reduced through the implementation of watershed
improvement projects. Additional costs are associated with repairing property, bridges, utilities,
and other infrastructure due to flood damage and streambank erosion (Brown and Caldwell
2010b). In most instances, it requires less of a financial investment to protect natural resources
and prevent damage to streams than it costs to restore impacted streams or treat polluted
waters.
Enhanced stream corridors can be an attractive asset within a community. Greenways and parks
along streams provide recreational opportunities and attract visitors who spend time and money
in the area. Black Mountain (TBM Undated) and Montreat
(TOM 2010?) have already developed greenways; Buncombe
County has prepared a greenways and trails master plan
(Buncombe County 2012) that envisions linking all
communities within the county. Implementing the plan and
BMPs to improve watershed health will employ local
businesses, such as engineers, land graders, landscapers, and
nurseries, to name a few. The residents and tourists that will
use the facilities will provide a long‐term economic benefit to
the upper Swannanoa River.
Upper Swannanoa River Watershed Plan 11 January 2016
Town of Black Mountain, N.C.
Social Factors
Healthy streams provide recreational opportunities such as fishing, boating, swimming, or just
getting your feet wet. Attractive stream corridors consist of clean‐flowing water and lush
vegetation that contribute to the livability and aesthetic benefits of a community. At risk
communities such as the elderly, poor, and other minorities that disproportionately live within
the floodway of streams are more directly affected by poor stream channel function and water
quality. Some will derive spiritual benefits from the surroundings, whereas others may derive
more creative benefits such as using natural materials to
make crafts or other artistic products. Walking paths and
greenways along streams provide hiking, biking, and
nature‐watching opportunities as well as provide health
benefits. When a stream is impaired, however, it cannot
fulfill these uses because the water may appear dirty and,
therefore, deter public use. A healthy environment results
in a healthy, thriving community, and investing in the
environment is an investment in the community.
Watershed Partners and the Planning Process
Previous Planning Efforts
Over the last 10 years the French Broad River basin, of which the Swannanoa River is a tributary,
has been the subject of many planning projects at both regional and local levels that have
recognized the high quality natural resources that exist in the basin. These plans also describe
threats to these resources as well as the need for projects that will improve water quality. The
most significant of these plans include:
French Broad River Basinwide Water Quality Plan (NCDWQ 2011) – Recommendations for
the 8‐digit HUC in which the Swannanoa River
watershed resides include increasing efforts on
stormwater management, erosion control and
pesticide education. In addition, they encouraged
the installation of stormwater control measures
(SCMs) to manage stormwater and prevent
associated pollutants from reaching surface
waters.
French Broad River Basin Restoration Priorities
(NCEEP 2009) – The upper Swannanoa River
watershed was identified as a targeted local
watershed (TLW). Specific goals for the 8‐digit
HUC in which the Swannanoa River watershed
resides include “working with local partners to
improve management of stormwater runoff,
controlling both stormwater volume and
pollutants, and promote[ing] low impact
Upper Swannanoa River Watershed Plan 12 January 2016
Town of Black Mountain, N.C.
development techniques to lessen impacts of new development, especially in the
expanding areas of Asheville, Black Mountain, Fletcher, and Hendersonville”.
2014 Comprehensive Plan Update for the Town of Black Mountain (TBM 2014) – Identifies
stormwater as a primary source of pollution and impact to waterways. It describes five
strategies to preserve the quality of water as it flows through Black Mountain.
Black Mountain Wellhead Protection Project: Planning Phase (LOSRCOG 1995)– A planning
document prepared by the Land‐of‐Sky Regional Council aimed at protecting the Town of
Black Mountain’s groundwater quality that serves wells used as the Town’s drinking water
supply.
Town of Black Mountain Stormwater Master Plan 2009 (TBM 2009) – Report prepared for
the Town of Black Mountain that describes the state of the watershed and the need to
protect water quality and stream channels from the impacts of stormwater. The plan
describes 12 potential projects that would reduce stormwater impacts and, in some cases,
provide recreational opportunities for residents and visitors.
Comprehensive Plan Alternatives for Montreat, North Carolina (TOM 2003) – This plan
describes steps the town can take to manage growth while maintaining environmental
conditions important to the community. It clearly states that while much of the land within
the town limits is in a natural state, it is at risk of being developed.
Natural Areas of Buncombe County, North Carolina: A Preliminary Inventory (NCNHP 1995,
2015a) ‐ The North Carolina Natural Heritage Program inventory identified several natural
areas of state and regional significance in the upper Swannanoa River watershed. They also
identified development and associated impacts as likely the greatest threat to the natural
areas.
North Carolina Wildlife Action Plan (NCWRC 2015) ‐ Recognizes habitat degradation as the
most widespread problem in the French Broad River basin. Large‐scale developments and
urbanization are identified as significant sources of non‐point source pollution and
sedimentation. Much of the sedimentation is attributed to poorly managed developments
on steep slopes and within riparian areas along tributaries. Due to poor habitat conditions,
the Swannanoa River watershed is not a priority watershed for aquatic species conservation
activities.
Strategic Plan for the Partners for Fish and Wildlife Program 2012 ‐ 2016, Southeast Region
(USFWS 2011) – The upper French Broad River subbasin, which includes the Swannanoa
River watershed, is a designated focus area of the USFWS for riparian corridor and wetlands
improvements that will benefit federally listed and rare aquatic species such as brook trout
(Salvelinus fontinalis) and bog turtle (Glyptemys muhlenbergii).
These plans provide a firm foundation for preparation of a WMP that will address the causes of
the impaired benthic community. Data from them will be used in identifying necessary
management actions and implementation schedules that will lead to water quality and aquatic
habitat improvements.
Public support for the Upper Swannanoa River improvement project is critical to achieving long‐
term success. A goal of this project is to motivate landowners, local businesses, and the general
public to take ownership of the problems facing the watershed and commit to the mission of
improving water quality. Public support for this plan will be achieved through a combination of
efforts including a stakeholder group, their personal contacts, and a public open house.
Upper Swannanoa River Watershed Plan 13 January 2016
Town of Black Mountain, N.C.
Stakeholder and Public Inputs
The Town of Black Mountain as sponsor of the watershed planning effort, convened a group of
stakeholders for the purposes of obtaining input on the WMP’s content. More specifically, the
group’s purpose was to aid in the development of a list of potential watershed improvement
projects and creation and implementation of an education and outreach program. The
stakeholder group was comprised of representatives of various agencies and organizations with
an interest in improving the upper Swannanoa River watershed (Table 1).
Two meetings of the stakeholder group were held in order to gain their views of problems in the
watershed, to get feedback on potential stormwater control projects within the Black Mountain
town limits, and to review and develop a proposed education and outreach program action plan.
Upon approval of the Upper Swannanoa River Watershed Management Plan, the Town of Black
Mountain will host an open house with the purposes of gaining public support in implementing
the WMP.
Table 1. Upper Swannanoa River Watershed Stakeholder Group Membership
Name Organization
Josh Harrold, Planning Director and Chair
Matt Settlemeyer, Town Manager
Max Wlodarczak (Intern)
Town of Black Mountain
David Currie Town of Montreat
Mark Brenner
Geoffrey Habron Warren Wilson College
Ed Williams
Zan Price N.C. Division of Water Resources
Karen Cragnolin
Amy Anino
Leah Hart Handwerger (Intern)
RiverLink
Mary Leonard‐White
Resident; former Chair Swannanoa River Flood
Risk Task Force and Town of Black Mountain
Alderwoman
Erica Anderson Land‐of‐Sky Regional Council of Government
Kim Williams
Fred Grogan
Jim Borawa
James Rogers
Equinox (consultant and meeting facilitator)
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Upper Swannanoa River Watershed Plan 14 January 2016
Town of Black Mountain, N.C.
Upper Swannanoa River Watershed Plan 15 January 2016
Town of Black Mountain, N.C.
WATERSHED CHARACTERIZATION
Geographic Location and Attributes
Geography
The Upper Swannanoa River Watershed (USRW), the focus of this WMP and defined as being the
portion of the Swannanoa River watershed upstream of its confluence with the North Fork
Swannanoa River is 22.2 mi.2 in area and located at coordinates 35.60463 ‐82.36837 (Figure 2). It
is identified as U.S. Geological Survey 12‐digit Hydrologic Unit Code (HUC 12) 060101050602
(USGS 2012). It is located in eastern Buncombe County; the Towns of Black Mountain and
Montreat lie almost entirely within its boundary. From this point the Swannanoa River flows
downstream approximately 15 miles to its confluence with the French Broad River.
Geographically, the USRW is located in eastern Buncombe County, North Carolina and is part of
the Southern Appalachian Mountains. The eastern boundary of the watershed is part of the
Eastern Continental Divide. Rain falling on the west of the divide flows to the Gulf of Mexico,
whereas rain falling to the east of the divide flows to the Atlantic Ocean. Flat Creek, Tomahawk
Branch, Camp Branch, and Wolfpit Branch are the largest tributaries. Elevations of the USRW
range from 5,408 above sea level to 2,227 feet above sea level at its confluence with the North
Fork Swannanoa River. Highways I‐40, US 70, and NC 9 run east‐west through the southern
portion of the watershed.
Geology
Geologically, the USRW is located within the Blue Ridge Mountain physiographic province that
is underlain with bedrock comprised of felsic granites, gneisses, and schists. Soils are usually
shallow on and near ridges, while in the valleys soils are more deeply weathered and formed
mostly from alluvium and colluvium parent materials. The primary soils of the watershed are
ultisols and inceptisols, which are typical of this region (USDA‐NRCS 2009).
Climate
Climatologically the USRW is in the Southern Mountain portion of the Humid Subtropical zone.
The average annual temperature is 54.4ºF with average annual low and high temperatures of
43.4ºF and 66.5ºF. January has the lowest average daily low temperature at 24.4ºF; July has the
highest average daily high at 83.7ºF. Climate normals for the period from 1981 to 2010 at Black
Mountain (station GHCND: USC00310843; Arguez et al. 2012) reveal an average of 47.2 inches of
precipitation per year, 7.3 inches of which is frozen precipitation. June is wettest month and
October is driest month with 4.75 and 3.09 inches of precipitation.
Upper Swannanoa River Watershed Plan 16 January 2016
Town of Black Mountain, N.C.
Population and Land Use Characteristics
Population
With regard to human population, 10 US Census block groups overlap with the USRW. Based on
the American Community Survey the estimated combined population of these ten block groups
is 13,211 people (USCB 2015). The combined 2010 population of the towns of Black Mountain
and Montreat was 8,604 (USCB 2010), a level that appears to have remained stable over the last
five years. Combined, the population of these towns make up 3.6% of the 238,318 total
population of Buncombe County.
Land Use
Land use and land cover within the USRW is typical for the Southern Appalachian region. The
USGS National Land Cover Dataset(Homer et al. 2015; Xian 2011; Homer 2007; Yang 2002)
revealed that in 2011 this watershed was 68.1% forested (9,654 acres) and 29.3% developed
(4,149 acres) with the remaining 2.6% being classed as other non‐developed or non‐forested
lands (Figure 2 and Table 2). Developed impervious surfaces such as roofs and paved parking
lots, as well less pervious turf lawns, make up 4.03% (612.9 acres) of the watershed. The most
developed areas are located along the lower elevation portions of stream valleys.
Land use and land cover changes between 2001 and 2011 reveal continued development within
the watershed (Table 2) despite a stable population. Total forested and agricultural area has
declined by about 30 acres, while total developed/urban area has increased by 11+ acres. Within
the developed/urban group, a loss of developed open space (<20% impervious) was replaced by
an increase in medium intensity developed area (50‐70% impervious), which would contribute an
increase in stormwater runoff. Herbaceous and shrub/scrub area increased by a combined 19
acres. Agriculture land use, which comprised 254 acres in 2001, decreased by about 11 acres
between 2001 and 2011.
Upper Swannanoa River Watershed Plan 17 January 2016
Town of Black Mountain, N.C.
Table 2. Land Use/Land Cover Characteristics and 2001/2011 Comparisons
NLCD Land Use Class 2011
Acres
2011
Watershed
%
Change
between
2001 &
2011
(Acres)
%
Change
in Area
%
Change
From
2001 to
2011
Total Developed/Urban 4,149 29.27 11.3 0.08
Developed, High Intensity
(>80% Impervious) 87 0.61 9.3 0.07 12.02
Developed, Medium Intensity
(50‐79% Impervious) 276 1.95 59.0 0.42 27.13
Developed, Low Intensity
(20‐49% Impervious) 617 4.35 ‐1.9 ‐0.01 ‐0.29
Developed, Open Space
(<20% Impervious) 3,169 22.35 ‐55.1 ‐0.39 ‐1.70
Total Forested 9,654 68.05 ‐19.6 ‐0.13
Mixed Forest 214 1.51 ‐0.4 0.00 ‐0.20
Deciduous Forest 9,321 65.76 ‐18.7 ‐0.13 ‐0.19
Evergreen Forest 118 0.83 ‐0.4 0.00 ‐0.37
Agriculture (Hay/Pasture) 254 1.79 ‐10.4 ‐0.07 ‐3.94
Total Other 120 0.85 17.6 0.12
Emergent Herbaceous Wetlands
(only 2011 data) 1 0.01 NA NA NA
Herbaceous 65 0.46 8.9 0.06 15.81
Barren Land 4 0.03 0.0 0.00 0.01
Open Water 2 0.01 0.0 0.00 0.01
Shrub/Scrub 26 0.19 9.8 0.07 59.53
Woody Wetlands 22 0.15 ‐1.1 ‐0.01 ‐4.88
Grand Total 14,177
Upper Swannanoa River Watershed Plan 18 January 2016
Town of Black Mountain, N.C.
Natural Resources
Protected Lands
The USRW is home to many unique and well‐known features of biological and ecological
significance. Areas containing populations of rare species, their habitats, and outstanding
aquatic and terrestrial natural communities have been identified as Natural Areas (NAs) by the
North Carolina Natural Heritage Program (NCNHP). The NCNHP also tracks other lands
managed to conserve uniqueness, biological diversity, and ecological function (NCNHP 2015a).
The NCNHP has identified three NAs within the USRW covering a total of 3,554 acres (Figure 2,
Table 3). These areas include some or all of such well‐known features as Greybeard Mountain,
Pinnacle Mountain, the Blue Ridge Assembly, the Montreat Watershed, and the Christmount
Natural Area.
Table 3. Natural Heritage Program Natural Areas
Natural Area Name Acres
Blue Ridge Assembly Natural Area 1,078
Christmount Natural Area 383
Montreat Watershed 2,093
Total 3,554
The above NAs are partially or wholly encompassed within a mix of privately and publicly owned
lands managed for conservation purposes. These managed lands may be protected by fee simple
ownership or be land on which a conservation easement exists or is otherwise managed to some
degree for conservation of biological and ecological purposes (Figure 2, Table 4). Some of these
lands are in public ownership and are used for recreation as well as for providing products such
as timber and drinking water. Other areas are privately owned and are designated as
conservation easements. Furthermore, some properties are not managed for conservation
purposes, but are still of conservation interest because of the natural resources that they contain.
Table 4. Other Managed Lands
Landowner Ownership Type Acres
Buncombe County Local Government 196
U.S. Forest Service Federal 9
Conservation Trust of North Carolina Private 3
Clean Water Management Trust Fund (NCDNCR) State 2,855
Southern Appalachian Highlands Conservancy Private 2,973
Montreat Watershed (Mountain Retreat; RHA) Private 2,088
Total 8,124
Important Plant and Animal Species
The Upper Swannanoa River Watershed is home to two rare plant species, four rare animal
species, and one rare natural community that are associated with streams and adjacent riparian
Upper Swannanoa River Watershed Plan 19 January 2016
Town of Black Mountain, N.C.
areas. According to state, and federal global rankings (Table 5; NCNHP 2015b) nearly all of these
ecological components are considered at risk of being eliminated due to the current condition of
their habitats.
Hellbender (amphibian), French Broad crayfish (crustacean), Superb jewelwing (damselfly), and
bog turtle (reptile) are all considered animal species of concern by the
State of North Carolina, U.S. Fish and Wildlife Service, and
NatureServe (NCNHP 2015a). The most notable of these is the bog
turtle, which is classified as Threatened and ranked as Imperiled by
North Carolina as well as the Federal Government. Globally, the bog
turtle is rare enough to be designated Vulnerable because of its highly
restricted range as well as population decline due to illegal collection.
Two vascular wetland plant species are known to occur within riparian
areas of the USRW. Of these, the large purple fringed orchid is listed
as Threatened and Imperiled by the State of North Carolina. One rare
wetland natural community, the Rich Montane Seep, also occurs
within the project area and is considered vulnerable to extinction by
North Carolina as well as by NatureServe™ (2015).
Table 5. At‐Risk Animal and Plant Species (Sheet 1 of 2)
Scientific Name Common Name State
Status1
State
Rank2
Federal
Status1
Global
Rank2 Habitat Type
Amphibians
Ambystoma talpoideum Mole Salamander SC S2S3 G5 Upland Animal
Cryptobranchus
alleganiensis Hellbender SC S3 FSC G3G4 Wetland Animal
Birds
Aegolius acadicus pop. 1
Northern Saw‐whet Owl ‐
Southern Appalachian
population
T S2B,S2N FSC G5T3 Upland Animal
Catharus guttatus Hermit Thrush SR S2B,S5N G5 Upland Animal
Falco peregrinus anatum American Peregrine
Falcon E S1B,S2N G4T4 Upland Animal
Setophaga cerulea Cerulean Warbler SC S2B FSC G4 Upland Animal
Vireo gilvus Warbling Vireo SR S2B G5 Upland Animal
Crustacean
Cambarus reburrus French Broad River
Crayfish SR S2 FSC G3 Aquatic Animal
Dragonfly or Damselfly
Calopteryx amata Superb Jewelwing SR S1S2 G4 Aquatic Animal
Upper Swannanoa River Watershed Plan 20 January 2016
Town of Black Mountain, N.C.
Table 5. At‐Risk Animal and Plant Species (Sheet 2 of 2)
Scientific Name Common Name State
Status1
State
Rank2
Federal
Status1
Global
Rank2 Habitat Type
Reptiles
Crotalus horridus Timber Rattlesnake SC S3 G4 Upland Animal
Glyptemys muhlenbergii Bog Turtle T S2 T(S/A) G3 Wetland Animal
Non‐Vascular Plant
Melanelia stygia Alpine Camouflage Lichen SR‐D S1S2 G5 Upland Plant
Vascular Plants
Hydrastis canadensis Goldenseal SR‐O S3 G3G4 Wetland Plant
Lilium grayi Gray's Lily T S3 FSC G3 Upland Plant
Platanthera grandiflora Large Purple Fringed
Orchid T S2 G5 Wetland Plant
Robinia hispida var. kelseyi Kelsey's Locust SR‐O S1 G4T1 Upland Plant
Scutellaria galericulata Hooded Skullcap SC‐H SH G5 Upland Plant
Thermopsis fraxinifolia Ash‐leaved golden banner SC‐V S2? G3? Upland Plant
Natural Communities
Acidic Cove Forest (Typic
Subtype) n/a S4 G5 Upland Natural
Community
Carolina Hemlock Forest
(Typic Subtype) n/a S2 G2 Upland Natural
Community
High Elevation Red Oak
Forest (Orchard Forest
Subtype)
n/a S2 G2 Upland Natural
Community
High Elevation Red Oak
Forest (Typic Herb
Subtype)
n/a S3 G4 Upland Natural
Community
High Elevation Rocky
Summit (Typic Subtype) n/a S2 G2 Upland Natural
Community
Low Elevation Rocky
Summit (Acidic Subtype) n/a S2 G3? Upland Natural
Community
Montane Oak‐‐Hickory
Forest (Acidic Subtype) n/a S4S5 G4G5 Upland Natural
Community
Northern Hardwood Forest
(Typic Subtype) n/a S3 G3G4 Upland Natural
Community
Pine‐‐Oak/Heath (Typic
Subtype) n/a S3 G3 Upland Natural
Community
Rich Cove Forest (Montane
Intermediate Subtype) n/a S4 G4 Upland Natural
Community
Rich Montane Seep n/a S3 G3 Wetland Natural
Community
1E = Endangered; T = Threatened; T‐S/A = Similarity of appearance to a Threatened taxon; TSR = Significantly Rare, but at the
periphery of its range; SC = Special Concern; SR‐P = Significantly Rare‐Peripheral; SC‐V = Special Concern‐Vulnerable (likely to
become Threatened within the foreseeable future; SR‐T = Significantly Rare throughout its range; FSC = Federal Species of
Concern.
2See NCNHP (2015b) for definitions of the state and global rankings.
Upper Swannanoa River Watershed Plan 21 January 2016
Town of Black Mountain, N.C.
Ecology
Ecologically, the USRW is part of the Blue Ridge Level III Ecoregion; with portions of the watershed in
the Southern Crystalline Ridges and Mountains, the Broad Basins, and the High Mountains Level IV
Ecoregions (Griffeth et al. 2002). The wide variety in geology, soils, and climate makes the Blue Ridge
one of the most floristically diverse ecoregions. Forest communities include Appalachian oak, northern
hardwoods, and, at the highest elevations, Southeastern spruce‐fir forests. Cove hardwoods and oak‐
pine communities are also prevalent.
Water Quality
No NCDWR ambient water quality monitoring sites exist in the USRW; however, the
Environmental Quality Institute (EQI) through its Volunteer Water Information Network (VWIN)
maintains a sample location just above the confluence with the North Fork Swannanoa River
(Figure 3). They collect monthly water samples to monitor the following water quality
parameters:
Nutrients as:
o Ammonia nitrogen (NH3)
o Nitrate‐nitrite nitrogen (NO3)
o Phosphorus (PO4)
Turbidity (nephelometric units; NTUs)
Total suspended solids (mg/L)
Conductivity (µS/cm)
Alkalinity (mg/L CaCO3)
pH
The raw data are then evaluated to create an index of water quality. The 2012‐2014 VWIN data
and analysis (Table 6; UNCA‐EQI 2009; EQI‐VWIN2015 and unpublished data) show that the
median values of all parameters fall below the regional average median. Based on these data,
water quality of the Swannanoa River at its confluence with the North Fork Swannanoa River was
rated as Good. The metric value for sediment was lower than that for nutrients and indicates
that eroded soil from stream banks and uplands is being transported downstream. Some of this
is likely the result of changes in stream flow and timing from stormwater runoff.
Upper Swannanoa River Watershed Plan 22 January 2016
Town of Black Mountain, N.C.
Figure 3. Water Quality and Biological Sampling Sites
Upper Swannanoa River Watershed Plan 23 January 2016
Town of Black Mountain, N.C.
Table 6. Upper Swannanoa River VWIN Water Quality Data, 2012‐20151
Year Month
NH3 NO3 PO4 Turbidity
(NTUs)
Total
Suspended
Solids (mg/L)
Conductivity
(µS/cm) Alkalinity pH
2012
January 0.04 0.3 0.05 1.2 0.4 43.4 14.0 6.8
February 0.04 0.3 0.03 2.6 0.8 41.8 16.0 6.8
March 0.14 0.2 0.04 23.0 12.8 68.9 17.0 6.8
April 0.08 0.2 0.09 4.6 3.2 40.3 17.0 6.8
May 0.07 0.2 0.07 1.9 5.2 41.6 12.0 6.9
June 0.06 0.2 0.09 4.2 4.8 38.0 10.0 6.8
July 0.19 0.1 0.04 17.0 14.8 42.8 22.0 7.0
August 0.19 0.1 0.06 50.0 37.2 36.2 20.0 7.0
September 0.14 0.2 0.09 4.8 6.8 45.0 17.0 7.0
October 0.06 0.3 0.16 1.5 1.2 43.8 14.0 7.0
November 0.05 0.2 0.07 0.6 0.8 47.0 15.0 7.0
December 0.04 0.2 0.05 1.1 1.2 40.2 19.0 7.1
2013
January 0.05 0.2 0.06 1.2 0.8 37.3 16.0 6.9
February 0.07 0.2 0.08 5.5 4.4 32.9 12.0 6.8
March 0.03 0.2 0.08 1.2 0.8 33.3 13.0 6.8
April 0.04 0.3 0.03 2.1 3.6 35.2 9.0 7.0
May 0.03 0.2 0.07 4.5 6.0 31.9 10.0 6.8
June 0.06 0.2 0.04 3.5 4.0 31.0 10.0 6.9
July 0.12 0.2 0.08 10.0 18.4 27.2 9.0 6.7
August 0.14 0.2 0.14 4.4 6.8 31.2 17.0 6.9
September 0.07 0.2 0.15 2.7 2.4 35.0 20.0 7.0
October 0.07 0.2 0.04 1.5 2.4 37.9 25.0 7.0
November 0.20 0.1 0.06 1.3 0.8 39.6 27.0 7.1
December 0.10 0.2 0.04 2.2 1.6 38.4 20.0 7.0
2014
January 0.08 0.3 0.04 1.1 0.4 32.6 17.0 6.9
February 0.06 0.2 0.02 1.2 0.4 35.1 14.0 6.8
March 0.03 0.1 0.03 1.1 0.8 34.4 15.0 7.0
April 0.05 0.2 0.04 1.2 2.8 34.7 16.0 6.8
May 0.07 0.2 0.03 2.3 3.2 34.4 15.0 7.0
June 0.09 0.3 0.06 4.1 4.0 37.6 19.0 6.8
July 0.06 0.5 0.05 4.0 3.6 39.9 14.0 6.9
August 0.06 0.2 0.06 3.2 2.4 42.3 14.0 6.8
September 0.09 0.1 0.05 35.0 4.0 44.4 14.0 7.0
October 0.06 0.1 0.04 2.5 0.8 42.3 14.0 7.0
November 0.06 0.2 0.02 1.2 0.8 41.6 13.0 7.0
December 0.07 0.2 0.05 2.7 2.4 40.1 10.0 7.0
Minimum 0.03 0.10 0.02 0.6 0.4 27.2 9.0 6.7
Median 0.07 0.20 0.05 2.5 2.6 38.2 15.0 6.9
Maximum 0.20 0.50 0.16 50.0 37.2 68.9 27.0 7.1
Regional Average
Median
0.09 0.50 0.08 6.0 4.8 62.0 22.0 7.0
1Sample location is at the US 70 crossing just upstream of the confluence of the Swannanoa River and North Fork Swannanoa River (EQI‐VWIN 2015)...
Upper Swannanoa River Watershed Plan 24 January 2016
Town of Black Mountain, N.C.
Benthic Communities
Benthic communities have been monitored at several sites in the USRW by the NCDWQ
(renamed the Division of Water Resources in 2014) and the EQI Stream Monitoring Information
Exchange (SMIE) program (Table 7). The most recent samples taken by the NCDWR on Flat
Creek upstream of Black Mountain have all produced Good‐Fair or better benthic community
ratings and likely continue to be less impacted by recent development. The most recent (2002‐
2003) NCDWR data taken at the SR 2500 (Blue Ridge Road) site were used as the basis for listing
the upper Swannanoa River on North Carolina’s 303(d) list of impaired streams because it was
rated as Fair. The SMIE data from three other sites within the USRW indicate Good and Good‐
Fair benthic communities (EQI 2014), but cannot be directly compared to the NCDWR ratings.
The NCDWR methods (NCDWR 2013a) are more rigorous as to the identification of individual
organisms and their tolerances to pollutants. However, the SMIE index (EQI 2014) is useful for
evaluating trends in ecological conditions of the stream.
Table 7. Benthic Macroinvertebrate Community Ratings by Site, 1987‐2015
Waterbody
(Organization1) Location Detail Month or Season
and Year Sampled
NC/SMIE IBI
Ratings
Aquatic
Habitat
Rating
Big Slaty Branch
(Flat Creek?)
(NCDWR)
Near NC 9 (Greybeard Trail?) December 1991 Excellent
(Little) Slaty Branch
(NCDWR) Near NC 9 (Greybeard Trail) December 1991 Excellent
Big Piney Creek (Branch?)
(NCDWR) Near NC 9 (Greybeard Trail?) December 1991 Excellent
Flat Creek
(NCDWR)
(Big) Piney Branch
Above US 70
At US 70
October 1987
December 1991
December 1999
Fair
Excellent
Good‐Fair
Swannanoa River
(EQI‐SMIE) At Flat Creek
Spring 2013
Fall 2013
Spring 2014
Fall 2014
Good‐Fair
Excellent
Good
Good‐Fair
Swannanoa River
(NCDWR) SR 2500; Blue Ridge Road
October 1987
August 2002
August 2003
Fair
Fair2
Fair2
Swannanoa River
(EQI‐SMIE) At Black Mountain Recreation Park
Spring 2011
Spring 2013
Fall 2013
Spring 2014
Fall 2014
Good‐Fair
Good
Good‐Fair
Good‐Fair
Fair
Swannanoa River
(EQI‐SMIE) At Kearfott Plant
Spring 2013
Fall 2013
Spring 2014
Fall 2014
Good‐Fair
Good‐Fair
Good‐Fair
Good‐Fair
1NCDWR ‐ North Carolina Division of Water Resources; EQI‐SMIE ‐ Environmental Quality Institute Stream Monitoring
Information Exchange.
2Sample data used as a basis for listing the USRW on North Carolina’s 303(d) list of impaired waters.
Upper Swannanoa River Watershed Plan 25 January 2016
Town of Black Mountain, N.C.
Fish Communities
No fish community assessments have been made by NCDWR in the USRW. The nearest sample
was taken near the Swannanoa community approximately 3 miles downstream from its
confluence with the North Fork Swannanoa River (NCDWR Unpublished data). At that location
three fish community assessments taken from between 1997 and 2012 revealed Good‐Fair or
Good ratings (Table 8). The aquatic habitat rating at that site was rated at 73; fish and benthic
communities can be affected when habitat ratings are below 70 (B. Tracy, NCDWR, Personal
Communication).
The only other fish data available for the USRW was collected by the North Carolina Wildlife
Resources Commission during a survey to identify the distribution of wild trout in the Swannanoa
River watershed. Their records (A. Bushon, NCWRC, Personal Communication) indicate that wild
trout are present as far downstream as Black Mountain Recreation Park.
Table 8. Swannanoa River Fish Community Ratings by Site, 1997‐2015
Waterbody
(Organization1) Location Detail Month/Year
Sampled
NCIBI
Ratings2
Aquatic
Habitat
Rating
Swannanoa River
(NCDWR) SR 2435; Old US Highway 70
September 1997
June 2002
July 2012
Good‐Fair
Good
Good‐Fair
73
1NCDWR = North Carolina Division of Water Resources.
2NCIBI – North Carolina Fish Community Index of Biotic Integrity (NCDWR 2013b)
Upper Swannanoa River Watershed Plan 26 January 2016
Town of Black Mountain, N.C.
This Page Intentionally Left Blank.
Upper Swannanoa River Watershed Plan 27 January 2016
Town of Black Mountain, N.C.
PLANNING ELEMENTS
Element A: Causes and Sources of Impairment
As stated in the introduction, the seven mile reach of the Swannanoa River upstream of its confluence
with the North Fork Swannanoa River is on North Carolina’s 303(d) list of impaired waters. The reason
for this designation is a degraded benthic invertebrate community (NCDWR 2014a). Urban related land
uses generally have negative impacts on stream biota.
In the case of the USRW, it is also related to logging and
agricultural activities of the early 20th century. As urban
development intensifies, fish and benthic
macroinvertebrate abundance, species richness and
diversity, and quality of biotic indices have been shown
to decrease (EPA 2012). In addition, numbers of more
pollutant tolerant species tend to increase.
Ecological conditions in the USRW River have been
degraded primarily due to the transition of the
watershed from one dominated by agriculture to one
now being urbanized. With urbanization, stormwater controls become more important to prevent
further stream degradation. To partially address this issue, local ordinances allow the use of “Green
Streets” in combination with other Low Impact Development design elements. Both the towns of Black
Mountain and Montreat also are required to control runoff from new construction under National
Pollution Discharge Elimination System (NPDES) stormwater permits issued by the North Carolina
Division of Energy, Lands, and Mineral Resources (Table 9). These permits require the towns to ensure
that stormwater control measures are maintained following construction of new or upgraded facilities.
It does not require existing facilities to be retrofitted; however, the Town of Black Mountain is currently
developing an inventory of their stormwater infrastructure so as to address deficiencies. Three
corporations are also required to control stormwater runoff under NPDES permits.
Table 9. Permitted Stormwater Dischargers
Permittee Type of Operation/Permit Receiving Stream
Town of Black Mountain Stormwater; MS‐4 Swannanoa River and tributaries
Town of Montreat Stormwater; MS‐4 Flat Creek and tributaries
Ingles Markets, Inc. Transportation facility Swannanoa River
Kearfott Corporation Metals fabrication Swannanoa River
Southern Concrete Materials, Inc. Ready‐mix concrete stormwater/wastewater
discharge
Swannanoa River
Upper Swannanoa River Watershed Plan 28 January 2016
Town of Black Mountain, N.C.
Urbanization brings with it changes to stream ecosystems described as “urban stream syndrome” (EPA
2012) that effect water quality, hydrology, and physical habitat. In
the case of the Upper Swannanoa River, the single largest source of
stream impacts has been the increase in impervious surface area and
the stress factors associated with runoff from those areas (Table 10).
Not only does the increase in impervious area increase the volume of
runoff, but it changes the peak volumes and timing of that runoff.
Those factors combined contribute to the destabilization of
downstream channels. In addition, stormwater from parking lots
transports vehicle contaminants (e.g. brake lining dust and
petroleum products) to receiving streams and increases in runoff water temperatures.
An important, but less prevalent contributor to stream degradation in the USRW is the lack of riparian
vegetation, which enables stream banks to resist scour from the increased peak stream flows and
frequencies, and filters pollutants and sediment from upland areas. Most of those locations identified
in this WMP have riparian vegetation that is comprised of turf grass or lawns with limited amounts of
woody vegetation. While some agricultural operations are adjacent to streams, most of which consists
of row crop farming. There are virtually no livestock within the project area, which are often the cause
of bank destabilization and increased nutrient and fecal coliform bacteria levels.
Table 10. Sources, Stressors, and Stress Indictors
Impairment Sources Potential Stressors Stress Indicators
Increased impervious surfaces
Commercial buildings
Warehouses
Roads and streets
Parking areas
Residential development on steep slopes
Increased peak flow
Increase peak flow frequency
Shortened peak flow duration
Eroded stream banks
Reduced pool depth
Channel scour
Stream bank instability
Sediment deposits
Aquatic habitat rating
Contaminants on impervious surfaces Increased contaminant levels
(metals, petroleum products,
nutrients)
Increase water temperatures
Altered benthic
community index
Reduced riparian vegetation Eroding stream banks Stream bank instability
and scour
Increased temperature
variation
Management measures that reduce the impacts of non‐point pollutant sources will result in improved
water quality, stream channel stability, and improved aquatic habitat conditions. Implementation of
management measures described in Element B are expected to achieve such improvements and lead to
an improved benthic macroinvertebrate community that will result in the Upper Swannanoa River
being removed from North Carolina’s impaired waters list.
Upper Swannanoa River Watershed Plan 29 January 2016
Town of Black Mountain, N.C.
Element B: Potential Projects and Management Measures
Watershed Management Goals
The ultimate goal of the WMP is to provide strategies leading to water quality and ecological
improvements of the USRW such that it can be removed from North Carolina’s 303(d) list of
impaired waters. The focus of the WMP is on reducing the impacts of stormwater runoff on water
quality and stream channel stability as well as enhancing riparian vegetation. Doing so will allow
aquatic habitat of the Swannanoa River to improve, leading to improved fish and benthic
macroinvertebrate communities and enabling the river to fully support its designated uses.
In the process of developing this WMP, goals and objectives from previous planning efforts were
recognized and included as part of this plan. All of these plans describe stormwater as the main
factor affecting water quality and stream function and suggest that a locally led effort in
implementing watershed improvement projects is needed. More specifically those plans
recommend pursuing the following actions:
Implement projects that support water quality improvement needs and objectives as
described in the following planning documents:
2014 Comprehensive Plan Update for the Town of Black Mountain (TBM 2014)
French Broad River Basinwide Water Quality Plan (NCDWQ 2011)
French Broad River Basin Restoration Priorities (NCEEP 2009)
Town of Black Mountain Stormwater Master Plan 2009 (TBM 2009)
Engage the community in water quality awareness and education.
Develop additional partnerships to implement projects that improve water quality
by engaging the business community and private citizens.
Stimulate economic opportunities in the community and create jobs by using local
businesses when management measures are implemented.
The following sections describe potential stormwater and stream improvement projects that
were identified by this study for the USRW. In addition to maps showing the location of each
potential project, a table describing some characteristics of each site is presented.
Implementation of management measures that support the achievement of these goals will
continue the process of improving water quality in the watershed.
Stormwater Impacts
During a rain event, stormwater flows across impervious surfaces and carries pollutants with it
into streams. Since these impervious areas do not provide a mechanism to slow the water down,
the result is often increased water velocities that scour receiving stream channels. These factors
combine to cause increased turbidities and sediment loads from the degraded banks and
subsequently impact aquatic habitat and fish and benthic communities.
The area of land within the USRW, including both the Towns of Montreat and Black Mountain, is
regulated under EPA’s Phase II stormwater regulations. Under this designation, new
development is required to provide stormwater control features to manage runoff from the
impervious surfaces of newly developed property. One approach local governments have taken
to address this issue has been the adoption of ordinances allowing the use of Low Impact
Development designs that can include the use of “Green Streets”. Although this approach serves
Upper Swannanoa River Watershed Plan 30 January 2016
Town of Black Mountain, N.C.
to reduce further degradation of water quality, it does not provide mechanisms to remediate
impacts caused by older developments. Impacts from these developments will continue unless
the sites are retrofitted with stormwater control features.
This WMP focuses on two types of watershed improvements. The first deals with sites having
conditions suitable for the installation of stormwater retrofit projects. The second targets
improving stream channels and riparian areas that either have been degraded by stormwater
runoff or lack adequate riparian vegetation to maintain stream bank integrity. Such stormwater
retrofit practices and stream improvements will be designed not only provide water quality
benefits, but improve aesthetics of the watershed. Both types of watershed improvement
projects will also serve as models that can be utilized for educational purposes.
Potential Stormwater Control Projects
A GIS and aerial interpretation effort was conducted to identify potential SCM sites (Appendix
A). These sites were then ground‐truthed, and analyzed spatially to determine both feasibility
and need. Several potential sites initially identified were found to be either inconsequential in
treatment potential, constrained by existing conditions, or were newer developments where
evidence of existing stormwater treatments were observed (cleanout pipes, monitoring wells)
implying that they are already in compliance with phase II requirements. Thirty‐one sites were
identified as potential retrofits sites (Figure 4 and Table 11). After field work and further analysis
that considered visually apparent conflicts such as land use, utilities, and topography, and then
also consolidating some of the sites, 21 were determined to be viable projects that could be
implemented within the 10‐year WMP planning period.
Implementation of these stormwater control measures will help offset the impacts of impervious
cover by mimicking the natural processes of forest ground cover. These processes slows runoff,
giving the stormwater an opportunity to infiltrate into the ground and helping recharge the water
table. Furthermore, by slowly releasing stormwater from a developed site, discharge rates of
large events are reduced to match natural effluent contributing to stream flow. Some
stormwater structures are effective in not only removing sediment, but also in reducing the levels
of pollutants such as nutrients (nitrogen and phosphorus) and heavy metals. Once stormwater
is captured by the treatment, pollutants are removed by aerobic and anaerobic processes. In
addition to reducing the potential for downstream bank erosion, SCMs also can provide
improved wildlife habitat by enhancing open space, reducing water temperatures, which are
often elevated by heat‐absorbing pavement, and to beautify the landscape by the addition of
water features and vegetation.
Surface area estimated for each treatment is based on the maximum percent of contributing
drainage area that can be treated. Detailed sizing calculations will be necessary when designing
individual treatment locations and can be referenced in the NCDWQ BMP manual (NCDWQ
2007). Deficiencies in available treatment areas are most commonly a result of available land to
implement the SCMs. However, these spatially deficient SCMs will still have treatment benefits,
and will still provide benefits such as habitat uplift and public awareness.
Although beyond the timeline of the WMP, the 10 sites considered not viable were retained in
the report for future consideration should unforeseen circumstances such as land donations,
change of land use, structure removal, or parallel projects provide opportunity for their pursuit.
Upper Swannanoa River Watershed Plan 31 January 2016
Town of Black Mountain, N.C.
Conceptual studies of 17 of the 21 final sites are included to help both aid in communicating with
landowners, and to convey intent when more detail design is pursued (Figure 5, Sheets 1‐13).
Due to the cursory nature of the concepts, they are not intended to be used for implementation,
and should not be construed as detailed drawings because factors such as, but not limited to, site
features, utility conflicts, land uses, and topography may vary.
Upper Swannanoa River Watershed Plan 32 January 2016
Town of Black Mountain, N.C.
This Page Intentionally Left Blank.
Upper Swannanoa River Watershed Plan 33 January 2016
Town of Black Mountain, N.C.
Figure 4. Distribution of Potential Stormwater Control Projects
Upper Swannanoa River Watershed Plan 34 January 2016
Town of Black Mountain, N.C.
Table 11. Potential Stormwater Control Retrofit Projects (Sheet 1 of 2)
Site Property Name Type of SCM Was The Site
Observed
Public
Land Land Use Drainage
Area (acres)
Impervious
Area
(Acres)
Percent
Impervious
Surface Area
REQUIRED for
SCM(s) (square
feet)
Surface Area
IDENTIFIED for
SCM(s) (square
feet)
1 Kearfott Wetlands Yes No Industrial 4.8 3.7 77 10,454 21,965
2, 3, 26
Foam and
Fabric/Terry Estate
Dr.
Bioretention Yes NO Commercial 1.9 0.9 46 8,700 5,404
4 Hopey, Dollar
General, Goodwill
Bioretention, Tree
Islands Yes No Commercial 3 3 100 13,060 11,188
5 WNC Shopping
Center Bioretention Yes No Commercial 1.0 1.0 100 870 2,005
6 Black Mountain
Commerce Park Wetlands Yes No Commercial/
Industrial 23 13 60 50,094 49,233
7 Carver Center Cistern No Yes Institutional 0.4 0.4 100 *1500 GAL. N/A
8 Golf Course
Parking
Bioretention,
Stream restoration Yes Yes Government/ Golf
Course 0.6 0.6 100 2,613 1,365
9 Apple Blossom
Motel Bioretention Yes No Commercial Has been confirmed on‐site that filled in pool conversion not likely feasible, or
effective
10 Laurel Circle (ROW
Storage)
Extended
Detention Yes No Transportation 8.1 1.4 17 10,585 3,416
11 CVS/US 70
Underground
Detention
Chamber
No Partial Commercial 28.5 15 50 **N/A
850 888
12 First Baptist
Church Bioretention Yes No Religious 1.0 0.9 90 900 722
13 Church Street Bioretention Yes Yes Government 3.0 2.0 67 1,500 1,750
14 Police Station Bioretention Yes Yes Transportation Constrained vehicle circulation
15 Richardson Bioretention Yes Yes Transportation Limited opportunities due to traffic volume, limited parking, and steep grade.
16 Bi‐Lo Bioretention No No Commercial Existing storm treatment in place. Grassed area is on high point, and is likely being
held for future development.
Upper Swannanoa River Watershed Plan 35 January 2016
Town of Black Mountain, N.C.
Table 11. Potential Stormwater Control Retrofit Projects (Sheet 2 of 2)
Site Property Name Type of SCM Was The Site
Observed
Public
Land Land Use Drainage
Area (acres)
Impervious Area
(Acres)
Percent
Impervious
Surface Area
REQUIRED for
SCM(s) (square
feet)
Surface Area
IDENTIFIED for
SCM(s) (square
feet)
17 Outparcel
Bioretention,
Channel
enhancement,
swales
Yes No Commercial
Although no significant pollutant treatment benefit would be realized, this site is
currently experiencing localized flooding. An SCM could improve this issue and would
be highly visible location adjacent to a school potentially providing educational
benefits.
18 Outparcel
Bioretention,
Channel
enhancement,
swales
Yes No Commercial 1.2 0.8 70 4,150 3,000
19 Tractor Supply Bioretention,
Swales Yes No Commercial 3.0 2.6 85 9,370 3,972
20 Robo Oil Filters Yes No Commercial 0.5 0.4 85 N/A N/A
21 Tong Sing Wetlands Yes No Commercial 2.2 1.5 70 14,374 4,887
22 Black Mountain
Primary
Swales,
Bioretention Yes Yes Institutional Spatial constraints with utilities and vehicular circulation. Also, no significant
treatment benefit would be realized.
23 Fresh Parking Bioretention Yes No Commercial 0.2 0.2 100 780 900
24 Right of Way Bioretention Yes Yes Transportation Buildings immediately adjacent, spatially constrained.
25 Lake Tomahawk
Parking Bioretention Yes Yes Parking 0.3 0.2 75 1,000 2,073
27 Montreat College
(vacant land) Wetlands No No Institutional 97.5 52.5 54 111,250 76,500
28 Library Bioretention Yes Yes Institutional 0.2 0.2 100 2,150 1,500
29 Residential parcel Extended
Detention Yes No Residential Likely a use conflict.
30 Post Office/Dry
Cleaner
Riparian
Restoration,
Extended
Detention
Yes No Commercial
(for Sale)
Water quality concern of dry cleaning effluent. Volume concerns (increased velocity
at outfall) as the stream enters a piped network under the Post Office.
31 Methodist Church
Parking
Bioretention/
Swales Yes No Religious
Possibly using open space between trees. Treatment would have to be non‐invasive
as space is likely used for function gatherings. Treatment opportunity from parking
area is minimal.
Upper Swannanoa River Watershed Plan 36 January 2016
Town of Black Mountain, N.C.
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Upper Swannanoa River Watershed Plan 37 January 2016
Town of Black Mountain, N.C.
A holistic approach was taken to determine the appropriate SCMs for each individual site.
Factors considered included slopes, soils, contributing hydrology, depth to bedrock, depth to the
seasonably high water table, targeted pollutants, and available space. It is important to
recognize that the siting and design of SCMs is as much of an art as a science (NCDWQ 2007).
Appropriately fitting treatments into the natural features of a site can not only help reduce
impacts to water quality, but address community concerns, safety issues, community
acceptance, and wildlife benefits (Table 12).
Table 12. Stormwater Control Measure Characteristics1
SCM
Type
Construction
Cost
Maintenance
Level
Safety
Concerns
Community
Acceptance
Wildlife
Habitat
Bioretention Medium‐High Medium‐High No Medium‐High Medium
Wetlands Medium Medium Yes Medium High
Wet Detention Basin Medium Medium Yes Medium Medium
Sand Filter High High No Medium Low
Filter Strip Low Low No High Medium
Grassed Swale Low Low No High Low
Restored Riparian Buffer Medium Low No High Medium‐
High
Infiltration Devices Medium‐High Medium No Medium‐High Low
Dry Extended Detention Basin Low Low‐Medium Yes Medium Low
Permeable Pavement System Medium‐High High No Medium None
Rooftop Runoff Management Medium Medium No High Low
1Source: NCDWQ Stormwater BMP Manual (NCDWQ 2007)
Upper Swannanoa River Watershed Plan 38 January 2016
Town of Black Mountain, N.C.
Figure 5. Conceptual Site Information Sheets (Sheet 1 of 13)
Site Notes:
Adjacent stream (possibly in
DOT ROW) is heavily incised.
Potential wetland will be
located in floodplain and
should be able to treat the
entire parking area.
Area is currently maintained
lawn and is possibly used for
company events, but design
could provide
walking/interpretive trails
promoting employee break
use.
Sewer line (and associated
easement) will be considered
with layout.
Existing site conditions
Example of a constructed
wetland.
)
Upper Swannanoa River Watershed Plan 39 January 2016
Town of Black Mountain, N.C.
Figure 5. Conceptual Site Information Sheets (Sheet 2 of 13)
Site Notes:
Provides
beautification
opportunities
along roadway.
Landscape
enhancements
could be visible
from Black
Mountain Ave,
Hwy 9, and
Vance.
FEATURE
Upper Swannanoa River Watershed Plan 40 January 2016
Town of Black Mountain, N.C.
Figure 5. Conceptual Site Information Sheets (Sheet 3 of 13)
Site Notes:
Would require parking
reconfiguration, although
the concept considers
existing concrete blocks
located throughout
parking. Existing
infrastructure (perimeter
inlets) would be used in
bioretention cells.
SCMS would be visually
appealing & reduce heat
island effect. Maintaining
visibility to businesses
needs to be considered
with plantings.
Existing site conditions.
Example of bioretention feature.
Example of
bioretention feature.
FEATURE
Upper Swannanoa River Watershed Plan 41 January 2016
Town of Black Mountain, N.C.
Figure 5. Conceptual Site Information Sheets (Sheet 4 of 13)
Site Notes:
Back paved area is expansive
and could likely be reduced
without affecting function.
Lidar indicates on‐site streams
which are likely piped.
Daylighted streams could
support wetland hydrology.
Close dialogue with property
owner would be necessary to
ensure existing uses for
property (storage yard) is
maintained.
Example of constructed wetland.
Upper Swannanoa River Watershed Plan 42 January 2016
Town of Black Mountain, N.C.
Figure 5. Conceptual Site Information Sheets (Sheet 5 of 13)
Site Notes:
Reduction of parking
(already limited) would be
required. Bioretention
would rely on surface
overflow, and underdrains
would daylight into stream
corridor. Depth would be
limited to underdrain
daylight elevation and
depth to water table. It is
possible to increase a
vegetated strip within the
bioretention.
Example of vegetated strip.
Example of
vegetated
strip.
Example of bioretention feature.
FEATURE
Upper Swannanoa River Watershed Plan 43 January 2016
Town of Black Mountain, N.C.
Figure 5. Conceptual Site Information Sheets (Sheet 6 of 13)
Site Notes:
Would require building up
roadway on low end of
drainage area and
accommodating a drive that is
connected. Potential volume
achieved needs further
analysis.
SCM primarily addresses
velocities draining to channel
by playground, so treatment
potential is nominal.
Perennial stream
determination is needed and
may limit options for concept.
Existing site conditions (bottom of Laurel Circle).
Example of vegetation and natural looking riser in
extended detention feature.
FEATURE
Upper Swannanoa River Watershed Plan 44 January 2016
Town of Black Mountain, N.C.
Figure 5. Conceptual Site Information Sheets (Sheet 7 of 13)
Site Notes:
Tomahawk Branch receives
outfall of two underground
pipe systems. Velocity
reduction is the goal. Cost will
likely be significant.
Coordination with NCDOT is
critical. There should be no
implications with
USACE/permitting since
stream is already piped.
Examples of underground detention structures
FEATURE
Upper Swannanoa River Watershed Plan 45 January 2016
Town of Black Mountain, N.C.
Figure 5. Conceptual Site Information Sheets (Sheet 8 of 13)
Site Notes:
Parking reconfiguration
maintains current number of
parking spaces. Proposed
bioretention would utilize
existing storm infrastructure.
Tree islands added to define
circulation and provide shade.
Existing site conditions (view from Montreat Road).
Example of a bio‐retention feature.
FEATURE
Upper Swannanoa River Watershed Plan 46 January 2016
Town of Black Mountain, N.C.
Figure 5. Conceptual Site Information Sheets (Sheet 9 of 13)
Site Notes:
Top of watershed contributing
to downtown infrastructure
issues. Greenstreet treatments
to accommodate driveways,
and on‐street parking. Use
traffic calming techniques with
integrated stormwater
treatment.
Examples of green street options.
Upper Swannanoa River Watershed Plan 47 January 2016
Town of Black Mountain, N.C.
Figure 5. Conceptual Site Information Sheets (Sheet 10 of 13)
Site Notes:
Utilize open space with existing
infrastructure to treat stormwater.
The presence of utilities are likely.
Additional studies are
recommended concerning
adjacent gas station surface
draining directly to inlets near
waterway. Tanks are also buried
immediately adjacent to
waterway. Around five
bioretention cells are anticipated.
Example of a
bioretention
feature.
(Above) example
of a trench drain.
Site conditions on a rainy day of US 70 at the Tractor
Supply entrance.
FEATURE
FEATURE
Upper Swannanoa River Watershed Plan 48 January 2016
Town of Black Mountain, N.C.
Figure 5. Conceptual Site Information Sheets (Sheet 11 of 13)
Site Notes:
Groundwater hydrology likely
present to support constructed
wetland. Also receives runoff
from site 20.
Upper Swannanoa River Watershed Plan 49 January 2016
Town of Black Mountain, N.C.
Figure 5. Conceptual Site Information Sheets (Sheet 12 of 13)
Site Notes:
Possibly need to involve
two parcels/landowners to
reconfigure parking.
FEATURE
Upper Swannanoa River Watershed Plan 50 January 2016
Town of Black Mountain, N.C.
Figure 5. Conceptual Site Information Sheets (Sheet 13 of 13)
Site Notes:
Informal grass parking
area to be converted to
bioretention. Existing
yard inlet can receive
overflow, but is too
shallow to tie to
underdrain. Underdrains
can potentially provide
treated stormwater for
irrigation re‐use (although
quantity of effluent will be
nominal).
FEATURE
Upper Swannanoa River Watershed Plan 51 January 2016
Town of Black Mountain, N.C.
Stormwater Control Management Measures
Non‐structural Control Measures ‐ Simple SCMs include
small, low cost measures that cumulatively can add up to
significantly reduce stormwater runoff impacts.
Homeowners and small businesses can easily implement
simple SCMs on their properties and usually at low cost.
Done properly these simple practices will beautify a
property, protect basements and foundations from water
seepage, and reduce water consumption and money that property owners spend on water
utilities. Each property is unique. Prior to implementing any of these solutions, property owners
should assess their site to ensure that their runoff will not cause or worsen storm runoff problems
for neighbors or create or add to erosion and flooding conditions on their properties. Even
though these solutions are referred to as ‘simple’, professional assistance with design and
construction may be needed. Landowners will be encouraged to install these features through
the education and outreach program.
Downspout Disconnects ‐ As the name implies, in cases that roof drains are tied into a closed
system, downspouts are physically disconnected from these systems. Downspouts from rooftop
gutter systems can be re‐routed to lawns and wooded areas to reduce runoff volume and stream
velocity. People interested in helping streams through these practices should expect minimal
investment in time and money. A homeowner with just a few downspouts will not incur as much
cost as those who manage a large commercial facility. The site to which the downspout is re‐
routed should be assessed for its infiltration and erosion potential. Rerouting downspouts to
steep slopes or clay soil areas may cause erosion or flooding. When these site conditions are
unavoidable, use of stone, erosion control fabric and vegetation can help control erosion and
promote infiltration. The more complicated a site, the more likely assistance of a design
professional is necessary. Many homeowners will find this solution easy and inexpensive to
implement and can likely undertake such a project on their own.
Rain Barrels and Cisterns ‐ Rain barrels and cisterns (Figure 6) provide a storage device to capture
rooftop drainage for later use on the site. Many people capture and reuse this water for their
gardens and landscape plantings. Rain barrels come in a variety of sizes, shapes, and colors. It
has become fairly commonplace to find 50 to 75 gallon barrels that make attractive additions to
the landscape, while cisterns tend to be much larger and may even be designed to be used for
non‐potable indoor plumbing. A simple, 50 gallon plastic rain barrel will typically cost $100 or
less. Users of this practice will need to make sure that they have screens over openings to keep
mosquitoes from using the reservoir as a breeding ground. They will also need to direct overflow
to a suitable location to keep it from seeping into foundations and basements.
Runoff Volume
One inch of precipitation falling on
1,200 square feet of roof produces
approximately 750 gallons of runoff.
Upper Swannanoa River Watershed Plan 52 January 2016
Town of Black Mountain, N.C.
Figure 6. Rain Barrel and Cistern Setup
Dry Creek Beds ‐ Dry creek beds (Figure 7) can be an attractive landscape amenity that can serve
the function of routing storm runoff from impervious rooftops, driveways, and parking lots into
a yard area where infiltration can occur.
The rough edges of the stones and the open spaces in between the rocks slow down runoff and
allow it to be absorbed by the ground. Landscape plantings within and surrounding the dry creek
bed also slow the water and promote infiltration. The stones and plants can also work together
to create natural habitat for birds and small mammals.
Figure 7. Dry Creek Beds in a Residential Setting
A rain barrel is attached to a
downspout and collects rain water.
An above ground cistern located at the City of
Morganton Parks and Recreation maintenance
building catches runoff from the roof. The water
is used to clean equipment.
Upper Swannanoa River Watershed Plan 53 January 2016
Town of Black Mountain, N.C.
Raingardens ‐ Raingardens are often simply excavated areas located in low points of a property
where stormwater accumulates. They are intended to slow, treat, percolate, and promote
evapotranspiration of stormwater. They rely primarily on a specified mix of medium placed with
the treatment cell and planted with native species. They usually do not include underdrains and
inlet structures.
Because they lack drainage structures, soils in raingardens need to be highly permeable to
function correctly. It is important to test the composition of existing soil to ensure the raingarden
is able to "draw down" between rain events.
Structural Stormwater Control Measures ‐ Structural SCMs typically treat larger areas of
imperviousness and “are intended to remove pollutants from stormwater runoff, reduce
downstream erosion, provide flood control, and promote groundwater recharge” (NCDWR
2007). Design professionals and precise installation parameters are most often needed when
implementing structural SCMs. They vary greatly in size, complexity, and function, often
incorporating plant material, soil mixes, and diversions that filter pollutants by natural processes.
Common examples of structural SCMs include bioretention, constructed wetlands (also known
as stormwater wetlands), wet ponds, and sand filters. Less common and often more expensive
solutions include permeable paving, regenerative stormwater conveyances, underground
storage chambers, and green roofs.
Bioretention ‐ Bioretention features are depressions that use soils and plants to treat storm
runoff, using many of the water storage and pollutant‐removal mechanisms that operate in
healthy forests. During storms, water temporarily ponds on the surface of a sand/soil bed and
then infiltrates through the bed. Nutrients are taken up by plants while microbes break down
organic substances (Figure 8).
Upper Swannanoa River Watershed Plan 54 January 2016
Town of Black Mountain, N.C.
Figure 8. Plant Uptake and Pollutant Removal Processes
Bioretention cells are intended to "draw down" or empty within 24‐48 hours following a rain
event, alleviating stagnant water and mosquito breeding concerns. Cells can be designed to
infiltrate water directly into native soils, if these soils are sufficiently permeable. If not,
underdrain systems may be necessary. To reduce the sizing requirements of bioretention
features, use of a structure can be installed to limit the amount of water the bioretention receives
to the first inch of rain. Larger storm volumes bypass the bioretention cells protecting them from
receiving amounts of water beyond what they are capable of treating. Overflow structures are
typically installed within the bioretention cell, especially when a bypass structure, such as a curb
cut in a parking lot, is not feasible. Bioretention can be used in a variety of topographic
conditions, and can generally treat runoff from areas of one acre or less (Figure 9).
Upper Swannanoa River Watershed Plan 55 January 2016
Town of Black Mountain, N.C.
Figure 9. Bioretention Features in Residential and Commercial Applications
A bioretention area effectively captures runoff,
preventing large volumes of polluted runoff from
entering a stream.
Upper Swannanoa River Watershed Plan 56 January 2016
Town of Black Mountain, N.C.
Swales ‐ Swales are utilized to convey water often in lieu of storm pipes. Simple grass lined
swales have limited pollutant removal benefits, but are often utilized in conjunction with other
SCMs. For example, in the case of the proposed Church Street retrofit, simple, dry swales may
need to be utilized in conjunction with bioretention cells in locations where pipe networks do not
exist.
Constructed Wetlands (also known as stormwater wetlands) ‐ Constructed wetlands are shallow
depressions constructed to mimic the functions of natural wetlands (Figure 10). They are
intended to increase the flow paths of the stormwater and temporarily store stormwater in pools
of varying depths that contain diverse wetland vegetation. The wetland uses physical, chemical,
and biological processes to filter pollutants. They can also be designed to provide stormwater
volume control. However, because they are shallow, stormwater wetlands require more surface
area than similar wet detention ponds, but provide much greater habitat due to the undulations
in topography.
Sediments that accumulate in the forebay of a constructed wetland need to be removed every 5
years or when the depth of the forebay diminishes by 50%. Wetlands should also be monitored
for the invasion of exotic plant species that should be removed promptly when found. Other
maintenance requirements include periodic inspection of the flow delivery mechanisms
upstream of the wetland to ensure that stormwater is able to get to the wetland as designed.
Otherwise, the wetland plant species may die. Trash and other debris removal may also be
needed periodically.
Figure 10. Examples of Constructed Wetlands
Constructed wetland after one growing
season. A constructed wetland at a city park captures
stormwater runoff from a residential development
and a parking lot. It also serves as a water feature
in the park and provides wildlife habitat.
Upper Swannanoa River Watershed Plan 57 January 2016
Town of Black Mountain, N.C.
Wet Ponds ‐ Wet retention ponds (Figure 11) are typically the most efficient use of land to meet
stormwater volume requirements. Like wetlands, wet detention basins can handle runoff from
large areas. In contrast to constructed wetlands, wet detention basins are usually deep and other
than a perimeter planting shelf, do not utilize vegetation for the treatment of pollutants or to
provide habitat diversity. Because of the safety issues posed by the pond depth, perimeter
fencing is often required.
Figure 11. Examples of Wet Ponds
Dry Ponds ‐ Dry ponds, most commonly in the form of extended detention, are intended to
capture stormwater and temporarily store it for 12‐24 hours promoting sediment and other
pollutants to settle out while releasing effluent at a controlled rate, which reduces peak discharge
to receiving streams (Figure 12). Since there is no long‐term storage of the water, extended
detention facilities do not increase outflow water temperature as do wet detention ponds.
Furthermore, creative application of these features can accommodate alternate uses, such as
parks or playing fields, between storm events. In a retrofit scenario, a structure such as a riser or
gabion wall is simply installed upstream of an existing culvert. Because of the flexible nature of
these features they make ideal flood mitigation opportunities, although water fluctuations
create a harsh environment for plant establishment. Debris may also be a concern depending on
the conditions in watershed upstream.
Upper Swannanoa River Watershed Plan 58 January 2016
Town of Black Mountain, N.C.
Figure 12. Examples of Extended Detention Retrofit Solutions
Upper Swannanoa River Watershed Plan 59 January 2016
Town of Black Mountain, N.C.
Maintenance ‐ Maintenance of SCMs is critical not only for them to function effectively, but to
maintain aesthetically pleasing landscapes. Currently Buncombe County, the Town of Black
Mountain and Montreat, require Operation and Maintenance Agreements upon approval of
stormwater facilities. Easements are also typically required to be included in the property deed
to provide the regulating entity access to the site for periodic inspection. Due to existing physical
constraints often associated with retrofits, maintenance access should be given special
consideration during the design phase.
Inspections of the SCM should occur yearly. Stormwater treatment methods, particularly
structural features, should be inspected by certified professionals that have a sound
understanding of the intended functions of the SCMs and the complexities of the infrastructure
involved. Certification programs such as those conducted by North Carolina State University
require individuals to satisifactorily complete a training workshop and pass a written
examination. Once certified, inspectors are required to attend continuing education workshops.
Potential Stream Improvement Projects
Based on GIS and aerial photo assessments and limited field observation, most stream channels
in the developed portion of the Upper Swannanoa River watershed are moderately incised. Less
steep portions of stream channel that were originally in agricultural use also show evidence of
having been straightened. The condition of the riparian area was considered sufficiently
degraded such that it would not function fully to reduce overland flow, filter sediment or be
resistant to erosion and associated bank failure. A modest number of stream reaches at least
500 feet in length have riparian areas that are sparsely wooded or entirely lacking woody
vegetation on one or both sides. Where riparian woody vegetation is sparse or lacking, stream
channels show evidence of instability. These conditions have resulted in erosion, sedimentation,
and degraded aquatic habitat. Incised and historically straightened streams are particularly
vulnerable to erosion as they are detached from their adjacent floodplains, which eliminates the
ability of the floodplain to mitigate storm flow velocities. Increased stormwater runoff from
developed areas only exacerbates this problem. Restoration of meandering stream channels
with established flood plains would be the ideal solution to this problem; however, in many cases
that will not be possible.
Approximately 31,000 feet of stream channel at 16 locations were identified as having some level
of degraded riparian areas on one or both sides of the stream channel (Figure 13 and Table 13).
The degradation ranges from stream banks lined with only turf or manicured lawns to that of
having few mature trees or woody shrubs. Tomahawk Branch has the most significant length of
stream channel that could benefit from reestablishment of a healthy native plant community in
the riparian area.
Approximately 18,800 feet (61%) of the stream channel with degraded riparian vegetation is
located in the Tomahawk Branch subwatershed. For this reason and because some of the
reaches are in public ownership, the Tomahawk Branch subwatershed should be given priority
for stream improvement projects. Improvement of riparian areas in that subwatershed alone
would not only improve overall watershed conditions but it would also reduce the maintenance
requirements of sediment catch basins constructed upstream of Lake Tomahawk and lower
water temperatures downstream of the lake. This condition may be the reason why no wild trout
were captured in the Swannanoa River downstream of its confluence with Tomahawk Branch
(Amanda Bushon, NCWRC, Personal Communication).
Upper Swannanoa River Watershed Plan 60 January 2016
Town of Black Mountain, N.C.
The remaining degraded stream improvement reaches are widely distributed throughout the
USRW. Three are located near the middle portion of the Flat Creek subwatershed and one is in
the Camp Branch subwatershed. The remaining five sites are within unnamed subwatersheds
most of which are on private lands. No effort was made to determine the number of parcels
involved or landownership. That will have to be done as part of the project development process.
Upper Swannanoa River Watershed Plan 61 January 2016
Town of Black Mountain, N.C.
Figure 13. Potential Stream Improvement Projects
Upper Swannanoa River Watershed Plan 62 January 2016
Town of Black Mountain, N.C.
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Upper Swannanoa River Watershed Plan 63 January 2016
Town of Black Mountain, N.C.
Table 13. Potential Stream Improvement Projects
Site
Number
Subwatershed / Location
Description
Stream
Channel
Length
(feet)
Ownership
Site Condition
Descriptor
from Aerial
Photos
1 Tomahawk Branch 7,457 Public Turf and lawn
2 Tomahawk Branch 3,318 Public Lawn
3
Tomahawk Branch/
Walker Cove Road 991 Private Lawn
4 Tomahawk Branch 1,844 Public
Adjacent to
roadway
5
Assembly Drive/
Flat Creek 502 Private Landscaped
6 Flat Creek 692 Private Landscaped
7
Avena Road/
Unnamed Tributary 1,544 Private Lawn/landscaped
8
Mountain View Avenue
Flat Creek 1,638 Private Lawn
9 Tomahawk Branch 2,896 Private Turf and lawn
10
Old Toll Circle/
Unnamed Tributary 1,020 Private Lawn/landscaped
11
Frances Avenue/
Unnamed Tributary 761 Private Lawn/landscaped
12
Hospital Road/
Unnamed Tributary 1,458 Private
Adjacent
agriculture
13
Tabernacle Road/
Unnamed Tributary 1,335 Private Lawn
14
Armory Road/
Unnamed Tributary 2,367 Private Turf and lawn
15
Llama Vista Court/
Camp Branch 844 Private Lawn
16
Tomahawk Branch/
Chapel Road 2,291 Private Lawn
Total 30,958
Upper Swannanoa River Watershed Plan 64 January 2016
Town of Black Mountain, N.C.
Stream Improvement Management Measures
Three options for stream improvement projects are proposed – riparian revegetation, stream
enhancement, and stream restoration. The main difference among them is the degree of stream
channel disturbance involved in their implementation. Simple definitions are as follows:
In all three categories of stream improvement, restoring vegetation within the riparian area plays
a vital role to the long‐term stability of the stream channel, its ability to filter out pollutants and
sediment, and to the ecological function of the aquatic community (Figure 14).
Figure 14. Functions of Woody Riparian Vegetation
Riparian Revegetation – This is the simplest type of stream improvement management measure.
It can be used where riparian vegetation is sparse or lacking but stream banks are relatively stable
and at slight risk of being undercut or eroded. This activity basically involves the planting of a
combination of native trees, shrubs, and herbaceous plants whose roots will bind the soil (Figure
15). In addition, the developing canopy provides shade resulting in lowered stream
temperatures. The herbaceous vegetation is effective at reducing soil erosion and filters
sediment and nutrients from upland areas.
Upper Swannanoa River Watershed Plan 65 January 2016
Town of Black Mountain, N.C.
Figure 15. Simple Riparian Revegetation Project Example
Before Planting – 2003 After Planting ‐ 2009
Riparian vegetation management must consist of two phases – control of non‐native invasive
plant species (if present) and reestablishment of a functioning riparian vegetation community
(Figure 15) comprised of primarily native tree, shrub, and herbaceous species (Table 14).
Table 14. Recommended Native Plants for Use in Stream Restoration and Enhancement
Stream Enhancement – This level of stream improvement is applied in areas where relatively
small sections of the stream bank are moderately unstable and woody riparian vegetation is
sparse. Generally bank reshaping of the unstable areas and revegetation is all that is required
(Figure 16). This approach also can be used where physical constraints such as roads, structures,
and utilities preclude a full restoration project.
Plant
Type Common Names of Recommended Species
Trees
River Birch, Bitternut Hickory, Shagbark Hickory, Sugarberry, Persimmon, Green Ash,
Blackgum, Sycamore, Black Cherry, Swamp Chestnut Oak, Water Oak, Shumard
Oak, Black Willow, White Basswood
Small
Trees &
Shrubs
Southern Sugar Maple, Painted Buckeye, Tag Alder, Service Berry, Red Chokeberry,
Common Paw, Sweet Shrub, Ironwood, Buttonbush, Alternate Leaf Dogwood, Silky
Dogwood, Hazelnut, Deciduous Holly, Winterberry, Virginia Willow
Herbs
Jack‐in‐the‐Pulpit, Swamp Milkweed, Fringed Saxifrage, Bladder Sedge, Hop Sedge,
Lurid Sedge, Broom Sedge, Tussock Sedge, Fox Sedge, Turtlehead, Umbrella Sedge,
Bottlebrush Grass, Joe Pye Weed, Boneset, Jewel Weed, Soft Rush, Rice Cutgrass
Upper Swannanoa River Watershed Plan 66 January 2016
Town of Black Mountain, N.C.
Figure 16. Stream Enhancement Project Example
Stream Restoration – This management measure can be used at sites where there is significant
streambank instability (Figure 17). Stream channels would be fully restored (NCSRI 2013) by
reestablishing proper channel dimension (cross‐section area), pattern (sinuosity), and profile
(slope). Stream restoration designs must take into account watershed size, stream slope, and
soils among other geomorphological characteristics. Restoration not only will lead to reduced
erosion, but improve sediment transport, and over the long term result in better in‐stream
habitat conditions. As with stream enhancement, restoration requires revegetation of the
riparian area with native shrubs, trees, and herbaceous plants as described above. Doing so will
maximize the riparian area’s ecological function and ability to filter sediment and other
pollutants originating from upland areas.
Each potential project will need to be assessed so as to determine the stream improvement
management measure that should be applied. Matching the level of restoration to existing
conditions will be the most effective and cost efficient way to improve the USRW.
Upper Swannanoa River Watershed Plan 67 January 2016
Town of Black Mountain, N.C.
The following criteria should be considered in determining the stream improvement
management measure to be applied:
Landowner(s) willingness to participate in implementing stream improvements on their
land; including, if necessary, entering into a conservation easement or other
maintenance agreement
Number of landowners involved
Location – is it in an area with significant amount of channel instability?
Size of stream – smaller streams are easier and less costly to improve than larger
streams
Protection status of upstream area; risk of development
Current condition of stream banks and channels (eroding, undercut, sloughing, etc.)
Condition of riparian vegetation (sparse, bare, turf, non‐native species present, etc.)
Potential for providing habitat for aquatic species (hellbender, freshwater mussels, etc.)
Figure 17. Stream Restoration Project Example
Strait Incised Channel Prior to Restoration Meandering Vegetated Channel Three Years
After Restoration
Upper Swannanoa River Watershed Plan 68 January 2016
Town of Black Mountain, N.C.
Element C: Estimates of Pollutant Load Reductions
Field data and generalized predictive models were used to determine the potential pollutant load
reductions from SCM retrofits and streambank improvements (Appendices A and B). While sediment
reduction loads were estimated for both categories of projects, nutrient reductions were estimated
only for SCMs.
Stormwater Control Measures
The 21 individual SCM retrofit opportunities identified for implementation during the 10‐year
planning period of the WMP (Table 10) will be tailored to individual site conditions. Cumulatively,
these features have the potential to reduce runoff volume and velocity as much as 100 acres of
existing impervious surfaces. While most SCM types are very efficient at removing suspended
solids, they also reduce nitrogen, phosphorus, and metals. Based on the conceptual designs and
pollutant removal efficiencies, it is estimated the proposed SCMs will result in an estimated
annual reduction of 1.8 tons of suspended sediment, 14 pounds of phosphorus, 106 pounds of
nitrogen, and 2.5 pounds of zinc (Table 15).
While the potential pollutant reductions from SCM retrofits appear to be small, the cumulative
benefits and value of reducing impervious surface area are significant. These benefits include
reducing stormwater volume and velocity and peak flow frequency, which contribute to
streambank erosion, improving aquatic wildlife habitat, and beautifying the landscape.
Additionally, the proposed SCM projects will be valuable demonstration tools in informing the
public about stormwater runoff and the ability of SCMs to remove sediment and nutrients.
Furthermore, implementing SCMs can achieve other goals stated in this WMP, particularly
mutual cooperation and collaboration among landowners, local governments, and nonprofit
groups. Such collaboration is necessary in order to achieve SCM implementation. As private
landowners learn about BMPs from demonstration projects on public land, they will consider
installing SCMs on their property. Finally, SCM installation requires professional services for
design, construction, and maintenance, thus employing contractors and stimulating the local
economy. The implementation of the SCMs, combined with other management measures, will
lead to improved ecological function of the Upper Swannanoa River Watershed.
Upper Swannanoa River Watershed Plan 69 January 2016
Town of Black Mountain, N.C.
Table 15. Estimated Pollutant Load Reductions from Stormwater Control Measures (Sheet 1 of 2)
Site
Number
Type of
Stormwater
Control Measure
(SCM)
Total Phosphorus Total Nitrogen
Annual
Load (lb)
Post
Treatment
Load (lb)
SCM Pollutant
Removal
Efficiency
Load
Removed by
SCM (lb/year)
Annual Load
(lb)
Post
Treatment
Load (lb)
SCM Pollutant
Removal
Efficiency
Load
Removed by
SCM (lb/year)
1 Wetland 1.0 0.7 0.35 0.4 8.3 5.0 0.40 3.3
2, 3, 26 Bioretention 0.4 0.2 0.45 0.2 2.9 1.9 0.35 1.0
4 Bioretention 0.7 0.4 0.45 0.3 5.1 3.3 0.35 1.8
5 Bioretention 0.2 0.1 0.45 0.1 1.7 1.1 0.35 0.6
6 Wetland 4.7 2.6 0.45 2.1 36.4 21.8 0.40 14.6
7 Cistern 0.1 0.1 0.0 0.5 0.5 0.0
8 Bioretention 0.1 0.1 0.45 0.1 1.0 0.7 0.35 0.4
10 Extended Detention 1.5 1.2 0.20 0.3 11.9 5.4 0.55 6.6
11 Detention 5.7 1.8 0.68 3.9 44.4 20.0 0.55 24.4
12 Bioretention 0.2 0.1 0.45 0.1 1.3 0.8 0.35 0.4
13 Bioretention 0.5 0.3 0.45 0.2 3.7 2.4 0.35 1.3
18 Bioretention 0.2 0.1 0.45 0.1 1.9 1.3 0.35 0.7
19 Bioretention 0.6 0.4 0.45 0.3 4.9 3.2 0.35 1.7
20 Filter 0.1 0.0 0.60 0.1 0.8 0.6 0.30 0.2
21 Wetland 0.5 0.3 0.35 0.2 3.5 2.1 0.40 1.4
23 Bioretention 0.0 0.0 0.45 0.0 0.3 0.2 0.35 0.1
25 Bioretention 0.1 0.0 0.45 0.0 0.5 0.3 0.35 0.2
27 Wetland 14.8 9.6 0.35 5.2 118.3 71.0 0.40 47.3
28 Bioretention 0.0 0.0 0.45 0.0 0.3 0.2 0.35 0.1
Totals 31.4 18.0 13.5 247.9 141.8 106.1
Upper Swannanoa River Watershed Plan 70 January 2016
Town of Black Mountain, N.C.
Table 15. Estimated Pollutant Load Reductions from Stormwater Control Measures (Sheet 2 of 2)
Site
Number
Type of
Stormwater
Control Measure
(SCM)
Total Suspended Solids Total Zinc as Representative Metal
Annual
Load
(lb)
Post
Treatment
Load (lb)
SCM
Pollutant
Removal
Efficiency
Load
Removed by
SCM (lb/year)
Annual Load
(lb)
Post
Treatment
Load (lb)
SCM
Pollutant
Removal
Efficiency
Load
Removed by
SCM (lb/year)
1 Wetland 145.6 21.8 0.85 123.7 0.5 0.5 0.0
2, 3, 26 Bioretention 51.4 7.7 0.85 43.7 0.2 0.2 0.0
4 Bioretention 88.4 13.3 0.85 75.2 0.3 0.3 0.0
5 Bioretention 29.5 4.4 0.85 25.1 0.1 0.1 0.0
6 Wetland 636.5 95.5 0.85 541.0 2.2 2.2 0.0
7 Cistern 9.1 9.1 0.0 0.0 0.0 0.0
8 Bioretention 17.7 2.7 0.85 15.0 0.1 0.1 0.0
10 Extended Detention 208.5 29.2 0.86 179.3 0.7 0.7 0.0
11 Detention 775.9 108.6 0.86 667.3 2.7 0.3 0.90 2.4
12 Bioretention 22.4 3.1 0.86 19.3 0.1 0.1 0.0
13 Bioretention 64.9 9.7 0.85 55.2 0.2 0.2 0.0
18 Bioretention 33.7 5.1 0.85 28.7 0.1 0.1 0.0
19 Bioretention 86.4 13.0 0.85 73.4 0.3 0.3 0.0
20 Filter 14.4 2.2 0.85 12.2 0.1 0.0 0.90 0.0
21 Wetland 61.9 9.3 0.85 52.6 0.2 0.2 0.0
23 Bioretention 5.9 0.9 0.85 5.0 0.0 0.0 0.0
25 Bioretention 8.5 1.3 0.85 7.2 0.0 0.0 0.0
27 Wetland 2,065.6 309.8 0.85 1,755.8 5.6 5.6 0.0
28 Bioretention 4.6 0.7 0.85 3.9 0.0 0.0 0.0
Totals 4,330.9 647.3 3,683.6 13.4 10.9 2.5
Upper Swannanoa River Watershed Plan 71 January 2016
Town of Black Mountain, N.C.
Stream Improvements
Sediment loading estimates for the 16 locations identified as needing some level of streambank
and riparian area improvements (one or both sides) were calculated using the USEPA’s
Spreadsheet Tool for Estimation of Pollutant Load (STEPL) model (Appendix C). The current
condition of the potential riparian enhancement locations were assessed using recent aerial
photographs. No field assessments of these sites were conducted.
The desktop analysis revealed that estimated sediment load reductions of up to 1,014 tons per
year could be achieved by implementing stream improvement projects at those locations (Table
16).
Table 16. Estimated Sediment Reductions from Streambanks
Site
Number
Location
Description and
Subwatershed
Stream
Channel
Length
(feet)
Channel
Migration
Rate
Estimated
Load
Production
(tons/year)
Estimated
Potential
Load
Reduction
(tons/year)
1 Tomahawk Branch 7,457 Severe 526 421
2 Tomahawk Branch 3,318 Moderate 49 39
3
Tomahawk Branch/
Walker Cove Road 991 Moderate 14 11
4 Tomahawk Branch 1,844 Moderate 27 22
5
Assembly Drive/
Flat Creek 502 Moderate 7 6
6 Flat Creek 692 Moderate 12 10
7
Avena Road/
Unnamed Tributary 1,544 Severe 106 85
8
Mountain View
Avenue
Flat Creek 1,638 Moderate 24 19
9 Tomahawk Branch 2,896 Severe 140 112
10
Old Toll Circle/
Unnamed Tributary 1,020 Severe 46 37
11
Frances Avenue/
Unnamed Tributary 761 Moderate 12 9
12
Hospital Road/
Unnamed Tributary 1,458 Severe 69 55
13
Tabernacle Road/
Unnamed Tributary 1,335 Moderate 30 25
14
Armory Road/
Unnamed Tributary 2,367 Moderate 35 28
15
Llama Vista Court/
Camp Branch 844 Moderate 13 11
16
Tomahawk Branch/
Chapel Road 2,291 Severe 157 125
Totals 30,958 1,268 1,014
Upper Swannanoa River Watershed Plan 72 January 2016
Town of Black Mountain, N.C.
Element D: Technical and Financial Assistance Needs
Partners
Successful implementation of any WMP necessitates local entities work as a team with
assistance from State and Federal agencies (Table 17). Western North Carolina has a very high
level of environmental consciousness that aims to maintain or improve its natural resources.
Local non‐profit organizations have cooperated with local government agencies and private
individuals to successfully address environmental problems. Some of these partners can provide
not only technical knowledge, but can provide funding and in‐kind matches to enhance the
strength of grant applications. The following table describes potential partners and the role they
may play in the implementation of the Upper Swannanoa River WMP.
Table 17. Potential Watershed Plan Implementation Partners
Organization Type Assistance
Technical Funding In‐Kind
Town of Black Mountain Local
Government
X X X
Town of Montreat Local
Government
X X X
RiverLink Non‐Profit X X X
Environmental Quality
Institute
Non‐Profit X X
Warren Wilson College Educational X
Montreat College Educational X
Private Citizen Private X X
Watershed Work Group
(to be established)
Non‐Profit X
(Volunteers)
X X
(Volunteers)
Businesses (being
recruited)
Private X X
Buncombe County Local
Government
X X
Buncombe County Soil
and Water Conservation
District
Local
Government
X X X
Natural Resources
Conservation Service
Federal
Government
X X X
N.C. Division of Water
Resources
State
Government
X
N.C. Wildlife Resources
Commission
State
Government
X
U.S. Fish and Wildlife
Service
Federal
Government
X X
TVA Quasi‐Federal
Government
X X
Upper Swannanoa River Watershed Plan 73 January 2016
Town of Black Mountain, N.C.
Technical Assistance
Technical assistance with all aspects of implementing the management measures will ensure
their success. While technical assistance in designing and constructing individual management
measures is necessary (Table 18), the importance of reaching out to landowners cannot be
understated. It is important to get their participation because in some cases they may be asked
to forgo some uses or values of their property. Because landowner interactions also may include
legal negotiations for easements, we also have identified some technical assistance needs for
landowner outreach. Technical and financial assistance needs for the Outreach and Education
program are presented in Element E.
Table 18. Technical Assistance Needs to Implement Management Measures
Management Measure Technical Assistance Provider
Landowner outreach Local conservation organizations
Outreach specialist (RiverLink, local watershed group, Southern Appalachian
Highlands Conservancy)
Experienced conservation easement specialist (attorney, if needed)
Residential SCMs
Rain barrels
Rain gardens
Local Cooperative Extension Office
Local conservation organization (RiverLink)
Stormwater Control Measures:
Wetlands
Bioretention feature
Cistern Installation
Filter
Maintenance
Stormwater design specialist
Civil engineer
Plant specialist
Permitting – local/state agencies
To be determined during project development
Stream Enhancement
Stream bank shaping
Permitting
Riparian revegetation
Experienced stream restoration specialist and equipment operator
Town of Black Mountain, Town of Montreat, Buncombe County, Division of
Water Resources, Division of Energy, Land, and Mineral Resources, U.S. Army
Corps of Engineers
Native plant specialist
Stream Restoration
Channel modification
Permitting
Stream construction
Monitoring
Stream restoration designer (engineer if needed)
Town of Black Mountain, Town of Montreat, Buncombe County, Division of
Water Resources, Division of Energy, Land, and Mineral Resources, U.S. Army
Corps of Engineers
Experienced construction supervisor and equipment operators
Experienced monitoring consultant
Survey channel dimension, pattern and profile
Conduct pebble counts
Conduct vegetation plot surveys
Conduct fish and macroinvertebrate surveys
Upper Swannanoa River Watershed Plan 74 January 2016
Town of Black Mountain, N.C.
Management Measure Costs
Costs for two categories of SCMs, structural and non‐structural, and a generalized cost of stream
improvements are presented. Costs for SCMs were developed using information from DSWC
(Undated) and CWP (2007) that was adjusted based on experience for constructing similar
projects in western North Carolina. Costs for implementing stream improvement management
measures are generalized because site specific needs will have to be determined. Due to the
unknowns at individual sites and funding limitations, the following items were not considered in
developing the project cost estimates:
Landowner outreach
Land acquisition costs (right‐of‐way costs, fee simple purchase, easements)
Surveying or special studies (engineering)
Attorneys’ fees
Fencing
Utility relocations and additional storm infrastructure
Road and street modifications (curbing)
The activities involved in developing a project’s cost and with the exceptions noted above
included the following:
Site assessment and survey
Conceptual design drawings for landowner review
Full design drawings
Construction drawings
Permitting
Contracting (bid documents and administration)
Construction
Revegetation (seed, plants, and labor to install
Maintenance
Monitoring
Non‐Structural SCM Costs ‐ Non‐structural SCM are considered ones that homeowners can
install on their own. They include rain barrels and raingardens that do not involve installation of
underdrains. It is expected that residential landowners will bear the cost of the materials and, if
necessary, installation (Table 19). Oftentimes, local non‐profit conservation organizations or
local governments may subsidize the cost of the rain barrels to encourage landowners to install
them for the environmental benefits they provide. No specific non‐structural projects are
proposed as part of the WMP. Non‐structural SCMs will be promoted as part of the Outreach
and Education part of this plan.
Homeowner installed rain barrels can cost as little as $100 or less for materials. Installation by a
service provider can cost significantly more when labor charges are involved.
Table 19. Estimated Costs to Implement Non‐structural SCMs
Feature Type Cost Range
Rain barrels $100‐$380
Raingardens Less than $100
Upper Swannanoa River Watershed Plan 75 January 2016
Town of Black Mountain, N.C.
Structural SCM Costs – Estimated costs to design and construct the 21 SCM features identified
in this plan varies from $4.07 to $20.93 per square foot of treatment area (Table 20). Estimated
total costs for individual sites ranges from about $11,600 to $615,825. Although some smaller
SCMs appear to be relatively inexpensive, when contractor mobilization is required the historic
cost for individual projects usually starts at about $50,000. It may be possible to reduce the costs
for some projects by bundling them with upcoming water and sewer rehabilitation projects being
planned by the Town of Black Mountain.
Table 20. Estimated Costs to Implement Structural SCMs1
Site
Number
Type of
Stormwater
Control Measure
Estimated
Treatment
Size
(square feet)
Cost per
Square Foot
of Treatment
Area
Estimated
Cost for
Treatment2
1 Wetland 21,965 $4.07 $89,399
2, 3, 26 Bioretention 8,700 $12.88 $90,096
4 Bioretention, Tree
Islands
11,500 $20.93 $215,585
5 Bioretention 2,005 $12.88 $25,824
6 Wetland 49,233 $8.05 $396,326
7 Cistern 2,500 gallon N/A $2,500
8 Bioretention 1,365 $12.88 $17,581
10 Bioretention 3,416 $7.47 $25,519
113 Detention,
Bioretention
888 N/A $386,400
12 Bioretention 722 $12.88 $9,299
13 Bioretention 1,750 $12.88 $22,540
18 Bioretention 3,000 $12.88 $38,640
19 Bioretention 3,972 $12.88 $51,159
203 Filter N/A $64,400
21 Wetland 4,877 $8.05 $39,340
23 Bioretention 900 $12.88 $11,592
25 Bioretention 2,073 $12.88 $26,700
27 Wetland 76,500 $8.05 $615,825
28 Bioretention 1,500 $12.88 $19,320
1Source – Stormwater BMP Costs. (DSWC Undated).
2Combines proposed SCM and paving removal cost, a 15% contingency, and 12% of construction
costs anticipated for design.
3indicates surface area in CVS parking for bioretention only. Cost should be considered a rough
estimate. Installation of underground chambers varies greatly depending on complexity and
size.
Upper Swannanoa River Watershed Plan 76 January 2016
Town of Black Mountain, N.C.
Stream Improvement Costs
Because the 16 potential stream improvement projects were not field surveyed as to their
condition or extent of needed improvements, individual cost estimates for each site could not be
calculated. In addition, costs associated with acquiring sites are highly variable due to the fact
that the projects are linear and often involve negotiating with multiple landowners. Instead, we
provide a range of costs for three categories of stream improvement – riparian revegetation,
enhancement, and restoration (Table 21). These categories reflect the amount of work necessary
to stabilize the stream channels and reestablish riparian vegetation.
Table 21. Estimated Costs to Implement Stream Improvement Projects
Improvement
Category Stream Condition Actions Required
Cost per
Linear Foot of
Stream
Channel
Riparian Area
Revegetation
Stream bank stable, small risk of failure
Woody vegetation sparse or absent
Herbaceous vegetation dominant with or
without significant bare areas
Non‐native invasive plant species often
present
Inventory existing plant community
Assess soil conditions
Control on‐native plant species
Amend soils as needed
Prepare planting plan
Install plants w/stem protectors if
needed
Monitor plant survival and replace
as needed
$80‐$100
Stream
Enhancement
Stream bank eroding in discrete areas,
moderate risk of failure
Woody vegetation sparse or absent
Herbaceous vegetation dominant with or
without significant bare areas
Non‐native invasive plant species often
present
Regrade stream banks to eliminate
erosion and to adjust channel cross‐
section dimensions
Inventory existing plant community
Assess soil conditions
Control on‐native plant species
Amend soils as needed
Prepare planting plan
Install plants w/stem protectors if
needed
Monitor plant survival and replace
as needed
$100‐$200
Stream
Restoration
Stream bank moderately to severely
eroding over large percentage of channel;
active bank failures present
Evidence of stream channelization
Channel entrenched such that stream
cannot access floodplain
Woody vegetation sparse or absent
Herbaceous vegetation dominant with or
without significant bare areas
Non‐native invasive plant species often
present
Regrade channel to restore proper
sinuosity, slope, and cross‐sectional
area
Restore stream access to floodplain
Inventory existing plant community
Assess soil conditions
Control on‐native plant species
Amend soils as needed
Prepare planting plan
Install plants w/stem protectors if
needed
Monitor plant survival and replace
as needed
$200+
Upper Swannanoa River Watershed Plan 77 January 2016
Town of Black Mountain, N.C.
Funding Sources
Without funding, implementation of the USRW plan will not be possible (Table 22). A variety of
potential funding sources are available to implement the Upper Swannanoa River Watershed
Management Plan. Because grant requirements, allowable uses, matching requirements, and
funding cycles often change, up‐to‐date details should be obtained from the agency before
starting the application process. This list does not include loan programs that may be available
to local government agencies.
Table 22. Potential Funding Sources for Watershed Improvement Projects
Funding Source Programs
Buncombe County Soil and Water
Conservation District
Agricultural Cost Share Program (ACSP)
Community Conservation Assistance Program for urban waters (CCAP)
Clean Water Management Trust Fund Legislated funding for stream restoration
Conservation Trust of North Carolina Provides grants to local land trusts to advance land conservation goals
Duke Energy Foundation Water Resources
Fund
Program to support improved water quality, quantity, and conservation; enhance fish
and wildlife habitats, expand public use of waterways; increase citizen awareness
about their roles in protecting water resources.
Environmental Protection Agency Multiple grant programs. For example ‐ Five Star Grants, Urban Waters Small Grants,
See http://www2.epa.gov/grants for funding opportunities.
Local Governments – Town of Black
Mountain, Town of Montreat,
Buncombe County
Utilize funds from these agencies to meet required matches for State and Federal
grants.
National Fish and Wildlife Foundation Multiple lists of grant opportunities. See http://www.nfwf.org/
whatwedo/programs/Pages/home.aspx#.VBrOUZRdWSp for details.
N.C. Department of Justice Environmental Enhancement Grants
N.C. Department of Transportation Non‐mitigation funding associated with road improvement projects
Special projects
N.C. Division of Parks and Recreation Adopt‐a‐Trail Program
Parks and Recreation Trust Fund (PARTF)
N.C. Division of Water Resources
USEPA 319(h) nonpoint source pollution watershed management and Implementation
Funds
USEPA 205(j) – Source Water Protection Planning Grants
N.C. Division of Mitigation Services Stream and wetland mitigation funding in targeted watersheds
N.C. Forest Service Forest Management Plan Program for private landowners (free)
Urban and Community Forestry Grants
N.C. Wildlife Resources Commission
Green Growth Grant. Technical assistance with habitat management plans and
providing fish sampling assistance. Value of some assistance may be useable as
match for other grants.
Private Entities – Developers, businesses,
and individuals
Property owners with potential projects will be recruited for In‐kind donations that
may include conservation easements, land, equipment, materials, supplies, or labor
Trout Unlimited Embrace‐A‐Stream Grants to engage local TU chapter with other partners
USDA Natural Resource Conservation
Service
Federal Farm Bill Programs – Environmental Quality Improvement Program (EQIP),
Conservation Reserve Program (CRP), Conservation Reserve Enhancement Program
(CREP)
U.S. Fish and Wildlife Service Partners for Fish and Wildlife (PARTF); Shade Your Stream Program; Endangered
Species Program, Wetlands Conservation Act Program
U.S. Forest Service Challenge Cost Share Projects (can conduct projects within administrative boundary
than can include private lands)
Z. Smith Reynolds Foundation Provides funding for projects that improve air and water quality and preserve natural
landscapes, but not land purchases, greenways, or plant species preservation.
Upper Swannanoa River Watershed Plan 78 January 2016
Town of Black Mountain, N.C.
This Page Intentionally Left Blank.
Upper Swannanoa River Watershed Plan 79 January 2016
Town of Black Mountain, N.C.
Element E: Outreach and Education Strategy
Outreach and education is a critical element to obtaining local support for and success in implementing the Upper Swannanoa River WMP. As
such, the outreach and education strategy is presented as a standalone element that includes the management actions, implementation
schedule, and needed financial and technical resources as well as qualitative success indicators. With input from the stakeholder group, the
strategy is composed of the following four components:
Overall Programmatic Outreach
Local Government Practices and Programs
Outreach to the Business Community
Public Stormwater Management Practices
The main objective of the education and outreach plan is to continue to improve watershed conditions that lead to heightened public
awareness about water quality within the USRW. It also is believed that by using outreach and education activities, individual landowners
will be motivated to implement management actions on their own and thus add to the watershed improvements identified in this plan.
Action Plans
The action plans (Table 23) on the following pages include the following:
Management Action – What is to be done
Targets – Quantification of how much of the action is proposed for the planning period
Responsible Party – Who will take the lead in implementing the management action
Schedule for Implementation – When the management action will begin or occur
Financial Resources – How much funding will be required
Potential Funding Resources – Where funding to implement the management action is likely to be obtained
Technical Resources Needed – What types of expertise will help facilitate getting management option implemented
Qualitative Success Indicators – What will be measured or documented to show success in implementing the management action
Upper Swannanoa River Watershed Plan 80 January 2016
Town of Black Mountain, N.C.
Table 23. Outreach and Education Action Plans (Sheet 1 of 4)
Overall Outreach
Management Actions
(what)
Targets
(how much)
Responsible
Party
(who)
Schedule for
Implementation
(when)
Financial
Resources
(how much)
Potential
Funding
Sources
Technical
Resources Needed
Qualitative Success
Indicators
Develop an Upper
Swannanoa River
Watershed Group to
Implement the
Outreach Action
Plan
Organizing
meeting; 2‐4
meetings per
year
Town of Black
Mountain,
Town of
Montreat,
RiverLink,
Warren Wilson,
DEQ
Year 1 Startup costs
($1,000) TBD None Working group established
Overall Outreach‐
Youth: Environmental
Education with Kids
1‐2 classroom
visits per year per
school‐ depends
on teacher
interest/response
RiverLink Year 1‐2 TBD based on
participation
Pigeon River
Fund, Duke
Energy
Foundation
None at this time;
use existing
resources
Teacher interest; number
of students educated / year
Overall Outreach‐
Youth and General
Public: BMP Education
Tours―Existing and Proposed Sites
1 annual
organized event,
self‐guided
option
throughout year
RiverLink
Initiate guided events
Summer 2016;
annually thereafter;
create self‐guided
information brochure
TBD TBD
None at this time;
use existing
resources
Number of people on
guided tours; brochures
distributed
Upper Swannanoa River Watershed Plan 81 January 2016
Town of Black Mountain, N.C.
Table 23. Outreach and Education Action Plans (Sheet 2 of 4)
Local Government Practices and Programs
Management Actions
(what)
Targets
(how much)
Responsible
Party
(who)
Schedule for
Implementation
(when)
Financial
Resources
(how much)
Potential
Funding
Sources
Technical
Resources Needed
Qualitative Success
Indicators
Ongoing Education
of Elected Officials:
Work to Educate Elected
Officials On Goals and
Projects of the Watershed
Plan
Once, in the near
term, and then
ongoing when
new officials
come on‐board
Towns of Black
Mountain and
Montreat in
partner with
RiverLink
Year 1/2; then as
needed TBD TBD None Number of presentations
and feedback
Ongoing Education
of Elected Officials:
Work to Educate Elected
Officials On What Share
of Pollutants Come From
Montreat and Black
Mountain
Implement as a
future
assessment is
completed
Towns work
with Warren
Wilson and
DENR to get
data that can
be easily
communicated
to officials
As assessments are
completed TBD TBD
Landscape
Architect,
Engineering;
Warren Wilson
College; DEQ
Actions taken by local
officials to address
watershed problems
Upper Swannanoa River Watershed Plan 82 January 2016
Town of Black Mountain, N.C.
Table 23. Outreach and Education Action Plans (Sheet 3 of 4)
Outreach to the Business Community
Management Actions
(what)
Targets
(how much)
Responsible
Party
(who)
Schedule for
Implementation
(when)
Financial
Resources
(how much)
Potential
Funding
Sources
Technical
Resources Needed
Qualitative Success
Indicators
Developers and
Business
Recognition: Develop a
Recognition Effort for
Those Working to Improve
the Watershed
1 individual,
business or group
per year
Towns of Black
Mountain and
Montreat
Annually beginning
2017 Minimal TBD None
Number of businesses
allied with Towns to
improve water quality
Outreach to
Landowners: Work
With
Landowners/Businesses
That May Be Willing to
Install Stormwater SCMs
1‐2 landowners
per year,
prioritize those
with the most
impervious
surface
Towns of Black
Mountain and
Montreat
As opportunities
arise
TBD
Depends on
project design
DEQ‐DWR;
CWMTF
Outreach
specialist;
stormwater
specialist
Number of stormwater
control measure projects
installed, number of
pollutants removed
Outreach to
Commercial
Landowners: Work
With
Landowners/Businesses
That May Be Willing to
Donate Stormwater or
Conservation Easement
1‐2 landowners
per year,
prioritize
conference
centers/major
landowners
RiverLink with
input from the
Towns of Black
Mountain and
Montreat
Year 1 ‐ Initial
Meeting in January to
discuss outreach
strategy
TBD RiverLink;
Towns
Outreach
specialist;
stormwater
specialist
Acres of land conserved
Outreach to
Chamber of
Commerce:
Presentation to Gain
Support from the Business
Community
1
presentation/yea
r
Town of Black
Mountain and
RiverLink
Year 1 ‐ Initial
Meeting in January to
discuss outreach
strategy; as needed
to maintain support
TBD TBD None
Number of new business
interested in partnering to
improve the watershed
Upper Swannanoa River Watershed Plan 83 January 2016
Town of Black Mountain, N.C.
Table 23. Outreach and Education Action Plans (Sheet 4 of 4)
Public Stormwater Management Practices
Management Actions
(what)
Targets
(how much)
Responsible
Party
(who)
Schedule for
Implementation
(when)
Financial
Resources
(how much)
Potential
Funding
Sources
Technical
Resources Needed
Qualitative Success
Indicators
Stormwater
Management
Practices: Develop
Demonstration Projects
(At Schools or Parks)
2 projects in a 5‐
year period
Towns of Black
Mountain, and
Montreat,
RiverLink
Years 1‐5, depending
on opportunities
Project
dependent
Pigeon River
Fund; DEQ‐
DWR; Duke
Energy
Foundation
Landscape
Architect,
Engineer
Number of BMPs
implemented
Stormwater
Management
Practices: Educational
Signage Installation
2 signs in a 5‐
year period RiverLink
Installed upon
completion of
construction
$2,500 per
sign, $5,000
total
Duke Energy
Foundation Graphic Designer Number of visitors to
BMPs and signs
Upper Swannanoa River Watershed Plan 84 January 2016
Town of Black Mountain, N.C.
Implementation Schedule and Accomplishments Tracking
The Outreach and Education program implementation schedule for the Upper Swannanoa River WMP presents the timeline over which
each management action will be achieved during the 10‐year planning period (Table 23). Target numbers for each management action
are taken from the management action plan tables in the previous section. The tables are also designed to compare actual versus planned
accomplishments for each management action. The planned accomplishment numbers will serve as interim milestones against which
progress in implementing the management measures will be evaluated. Significant deviations from the planned accomplishments will
be an indicator that the action plan may need revision.
Table 24. Upper Swannanoa River Outreach and Education Implementation Schedule (Sheet 1 of 2)
Management Action
Year
Short‐Term Mid‐Term Long‐Term Targets 1 2 3 4 5 6 7 8 9 10
Overall Outreach
Watershed Group – Establish an Upper
Swannanoa River Watershed Group to
Implement the Outreach Action Plan
Planned 3 3 3 3 3 3 3 3 3 3
Establish working
group year 1; meet 2‐4
times/year
Actual
Children’s Programs ‐ Environmental
Education Program with Kids
Planned 3 3 3 3 3 3 3 3 3 3 Black Mtn. Primary &
Elementary,
Montessori School Actual
Youth & General Public ‐ BMP Education
Tours of existing and proposed sites
Planned 1 1 1 1 1 1 1 1 1 1 10 guided tours Actual
Local Government Practices and Programs
Education of Elected Officials: Work to
Educate Elected Officials On Goals and
Projects of the Watershed Plan
Planned 1 1 1 1 1 5 presentations; 1 in
year 1, as needed
thereafter Actual
Education of Elected Officials: Work to
Educate Elected Officials On What Share of
Pollutants Come From Montreat and Black
Mountain
Planned Implement as Assessment Data Collected and Ready for Presentation
3 presentations
Actual
Upper Swannanoa River Watershed Plan 85 January 2016
Town of Black Mountain, N.C.
Table 24. Upper Swannanoa River Outreach and Education Implementation Schedule (Sheet 2 of 2)
Management Action
Year
Short‐Term Mid‐Term Long‐Term Targets 1 2 3 4 5 6 7 8 9 10
Outreach to the Business Community
Developers and Business Recognition:
Develop a Recognition Effort for Those
Working to Improve the Watershed
Planned 1 1 1 1 1 1 1 1 1 1
10 presentations Actual
Outreach to Landowners: Work With
Landowners/Businesses That May Be Willing
to Install Stormwater SCMs
Planned 1‐2 1‐2 1‐2 1‐2 1‐2 1‐2 1‐2 1‐2 1‐2 1‐2
15 contacts
Actual
Outreach to Commercial Landowners: Work
With Landowners/Businesses That May Be
Willing to Donate Stormwater or
Conservation Easement
Planned 1‐2 1‐2 1‐2 1‐2 1‐2 1‐2 1‐2 1‐2 1‐2 1‐2
15 contacts
Actual
Outreach to Chamber of Commerce:
Presentation to Gain Support from the
Business Community
Planned 1 1 1 1 1 1 1 1 1 1
10 presentations
Actual
Public Stormwater Management Practices
Stormwater Management Practices: Develop
Demonstration Projects
Planned 2 1 1 1 1 1 2 projects within first
5 years Actual
Stormwater Management Practices:
Educational Signage Installation
Planned 2 2 signs within first 5
years Actual
Upper Swannanoa River Watershed Plan 86 January 2016
Town of Black Mountain, N.C.
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Upper Swannanoa River Watershed Plan 87 January 2016
Town of Black Mountain, N.C.
Element F: Schedule for Implementation
Stormwater Control Measures
The timeframe to implementation of SCMs included in this plan was determined using
stakeholder input and a decision‐making matrix (Table 25) that considered the following factors:
Landowner willingness
Constructability
Cost
Treatment area
Pollutant load reduction and flow attenuation
Public benefit and visibility
Because the length of time it may take to develop individual projects, it was decided to assign
them to three time periods within the 10‐year life of the WMP – 1‐3 years (short‐term); 4‐7 years
(medium‐term), and 8‐10 years (long‐term). The stakeholder group discussed the favorability
rating assigned to each of the individual projects and then, through a weighted voting process,
each project was assigned to an implementation time period. During this process, it was
determined that nine of the SCM projects could not be implemented during this planning period
due to the amount of work that would be required to bring them to fruition or because there
were concerns that the projects may not be feasible. The stakeholder group felt those projects
were important enough to keep in the planning document for consideration if site conditions
change or when the WMP is revised.
Upper Swannanoa River Watershed Plan 88 January 2016
Town of Black Mountain, N.C.
Table 25. Stormwater Control Measures Implementation Schedule1
Site Property Name
Landowner
Willingness/On
Public Land2
Constructability
and Cost
Benefit to
Stormwater
Treatment/
Reduction
Public
Benefit
and
Visibility
Implementation
Time Period2
(Years)3
1‐3 4‐7 5‐10
1 Kearfott TBD X
2, 3,
26
Foam and
Fabric/Terry Estate
Dr.
TBD X
4 Hopey/Dollar
General/Goodwill TBD X
5 WNC Shopping
Center N/A N/A N/A N/A X
6 Black Mountain
Commerce Park TBD X
7 Carver Center N/A N/A N/A N/A X
8 Golf Course Parking X
9 Apple Blossom
Motel N/A N/A N/A N/A Future
10 ROW Storage X
11 CVS/Hwy 70 TBD X
12 First Baptist Church TBD X
13 Church Street X
14 Police Station N/A N/A N/A N/A Future
15 Richardson N/A N/A N/A N/A Future
16 Bi‐Lo N/A N/A N/A N/A Future
17
19
Outparcel – US 70
Tractor Supply TBD Future
X
18 Outparcel TBD X
20 Robo Oil N/A N/A N/A N/A X
21 Tong Sing TBD X
22 Black Mtn. Primary N/A N/A N/A N/A Future
23 Fresh Parking TBD X
24 Road Right‐of‐Way N/A N/A N/A N/A Future
25 Lake Tomahawk X
27 Montreat College
(vacant land) TBD X
28 Library X
29 Residential parcel Future
30 Post Office/Dry
Cleaner TBD X
31 Methodist Church
Parking N/A N/A N/A N/A X
1Color key: Favorable; Moderately Favorable; Unfavorable.
2For most projects landowner willingness is not known and will be obtained during outreach efforts (TBD); public lands were
considered favorable for development; landowner willingness for projects marked N/A was either not applicable because they
involve public right‐of‐ways.
3Potential project marked as ”Future” projects were considered important, but have constraints that do not make them
practical to consider for this planning period.
Upper Swannanoa River Watershed Plan 89 January 2016
Town of Black Mountain, N.C.
Stream Improvement Projects
Of the 16 stream improvement projects identified as needing channel and riparian vegetation
enhancements, the largest ones are located within the Tomahawk Branch subwatershed (Table
14). Those portions of stream on public land will be targeted for implementation first (Table 25);
efforts will be made to include those on private lands as part of the overall approach to improving
the Tomahawk Branch subwatershed. Since no on‐site assessments or landowner contacts have
been made and the costs for the needed stream improvements could be significant, depending
on site conditions, the first projects will likely not occur until mid‐term of the planning cycle.
Although projects outside of Tomahawk Branch are not targeted for this planning period, efforts
to recruit those landowners into participating will occur as part of the Outreach and Education
Program. If those landowners are found to be willing to implement projects on their properties,
funding for design and construction will be pursued.
Table 26. Implementation Schedule for Stream Improvement Projects
Site
Num
ber
Location Description and
Subwatershed Ownership
Implementation Time Period
1‐3 4‐7 8‐10
1 Tomahawk Branch Public X
2 Tomahawk Branch Public X
3
Tomahawk Branch/
Walker Cove Road Private X
4 Tomahawk Branch Public X
5
Assembly Drive/
Flat Creek Private TBD
6 Flat Creek Private TBD
7
Avena Road/
Unnamed Tributary Private TBD
8
Mountain View Avenue
Flat Creek Private TBD
9 Tomahawk Branch Private X
10
Old Toll Circle/
Unnamed Tributary Private TBD
11
Frances Avenue/
Unnamed Tributary Private TBD
12
Hospital Road/
Unnamed Tributary Private TBD
13
Tabernacle Road/
Unnamed Tributary Private TBD
14
Armory Road/
Unnamed Tributary Private TBD
15
Llama Vista Court/
Camp Branch Private TBD
16
Tomahawk Branch/
Chapel Road Private X
Upper Swannanoa River Watershed Plan 90 January 2016
Town of Black Mountain, N.C.
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Upper Swannanoa River Watershed Plan 91 January 2016
Town of Black Mountain, N.C.
Element G: Measurable Milestones
The USRW WMP accomplishments tracking tables presented below provide a timeline over which each management action will be achieved
during the 10‐year planning period (Tables 26‐28). Target numbers for each management action are taken from the management action plan
tables in Element F and distributed across years based on stakeholder input. The tables also are designed to compare actual versus planned
accomplishments for each management action. The planned accomplishment numbers will serve as interim milestones against which progress
in implementing the management measures will be evaluated. Significant deviations from the planned accomplishments will be an indicator
that the action plan may need revision.
Table 27. Measurable Milestones and Implementation Tracking for Stormwater Control Measures
Management Action Year Short‐Term Mid‐Term Long‐Term Target 1 2 3 4 5 6 7 8 9 10
Install bioretention SCMs Planned 2 10 2 14 features installed
Actual
Install extended detention structures Planned 1 1 1 3 features installed Actual
Install cisterns Planned 1 1 feature installed Actual
Install filter system Planned 1 1 feature installed Actual
Install wetland system Planned 3 1 4 features installed Actual
Table 28. Measurable Milestones and Implementation Tracking for Stream Improvement Projects
Management Action Year Short‐Term Mid‐Term Long‐Term Target 1 2 3 4 5 6 7 8 9 10
Stream Improvement Projects:
Conduct landowner outreach & field
assessments
Planned 16 sites 3‐5 3‐5 3‐5 3‐5 3‐5 3‐5 3‐5 Contact landowners at
16 identified sites Actual
Stream Improvement Projects:
Restore riparian area vegetation &
stabilize stream channels
Planned 1,000 3,000 feet 3,000 feet
7,000 feet
Actual
Upper Swannanoa River Watershed Plan 92 January 2016
Town of Black Mountain, N.C.
Table 29. Measurable Milestones and Implementation Tracking for Monitoring and Maintenance
Management Action
Year
Short‐Term Mid‐Term Long‐Term Target 1 2 3 4 5 6 7 8 9 10
Water chemistry
Ambient (VWIN)
Planned X12 X12 X12 X12 X12 X12 X12 X12 X12 X12 See Table 7.6 for
details Actual
Biological Monitoring
Benthic macroinvertebrates (NCDWR)
Planned X X X Sample established
site at 5‐year intervals Actual
Biological Monitoring
Benthic macroinvertebrates (SMIE)
Planned X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 Spring and fall
samples at 3
established sites Actual
Biological Monitoring
Fish Community (NCDWR)
Planned X X X Establish baseline in
year 1; repeat at 5‐
year intervals Actual
Stewardship monitoring Planned X X X X X X X X X X Monitor installed
projects annually Actual
Watershed Management Plan Review,
Update and Revision
Planned X X Review watershed
plan at 5‐year
intervals; revise as
needed or at year 10 Actual
Upper Swannanoa River Watershed Plan 93 January 2016
Town of Black Mountain, N.C.
Element H: Criteria of Pollutant Load Reduction Achievements
Stormwater Control Measures
The main pollutant issue affecting downstream stream channel stability and benthic
communities is the volume and frequency of stormwater runoff from existing impervious
surfaces. The number of SCMs installed and their effect on water quality and pollutant
reductions will be used to assess how well pollutant reduction objectives are being achieved
(Table 30). Pollutant reduction objectives should be achieved for rainfall events that do not
significantly exceed the 1‐year 24‐hour design storm of the SCMs. In addition, a portion of the
sediment, nutrients, and metals will be filtered from the runoff. These changes will result in
improved water quality and lower stream sediment loads that should lead to an improved
benthic community.
Table 30. SCM Pollutant Load Reduction Achievement Criteria
Pollutant
Issue
Management Action Target Criteria
Stormwater
runoff
Installation of stormwater control features Number of SCM features installed
Impervious surface area treated
Reduction in volume of runoff
Reduction in frequency of runoff
Sediment captured
Reduction in nutrients
Reduction in metals
Stream Improvement Measures
Pollutant load reduction criteria achievements will be determined by the linear footage of stream
channel and acreage of riparian area revegetated (Table 30).
Table 31. Stream Improvement Pollutant Load Reduction Achievement Criteria
Pollutant
Issue
Management Action Target Criteria
Streambank
erosion
Stream improvements:
Streambank enhancement
Stream channel restoration
Riparian area revegetation
Linear feet of stream channel improved
o Feet of bank reshaping
o Feet of channel restoration
Acres of riparian area revegetated
o Number of native plants installed
o Survival of plants
Upper Swannanoa River Watershed Plan 94 January 2016
Town of Black Mountain, N.C.
Element I: Watershed Monitoring Plan
To determine the effectiveness of management measures being implemented, the physical and
ecological conditions of the watershed should be monitored over time. As specific management
actions are completed, particularly those to control stormwater, stream channels are expected to
stabilize, leading to an improvement in ecological function and aquatic habitat conditions. Secondary
indicators of improved water quality conditions include improvements in the benthic
macroinvertebrate and fish communities. A standard suite of water chemistry parameters should also
be monitored to ensure that other water quality is being maintained.
Monitoring activity, frequencies, benchmark levels, and target levels have been developed and are
presented in Table 32. Benchmarks for fish and benthic macroinvertebrate communities and aquatic
habitat are based on metric scoring methods, whereas water quality parameters are measured against
NCDWR and EPA standards.
The following monitoring program is designed to assess overall watershed conditions. Subwatershed
or site specific monitoring may be necessary to determine water quality and ecological improvements
at localized levels or associated with specific watershed improvement projects.
Water Chemistry
A suite of water chemistry parameters is measured monthly by VWIN volunteers at a point near
the lower boundary of the project watershed (Figure 3, Table 32). To ensure that pollutants are
not becoming a problem in the upper Swannanoa River Watershed, the monthly sampling for
these parameters should continue for the life of the WMP.
Ecological
To determine if there are ecological effects from the installation of watershed improvement
projects, benthic macroinvertebrate and fish communities as well as aquatic habitats should be
monitored on a regular basis.
Benthic Macroinvertebrates – The NCDWR has one established benthic macroinvertebrate
sample site (Figure 3 and Table 7) that was sampled to establish a biotic integrity rating that was
used as a basis for listing the USWR on the 303(d) impaired waters list. This activity follows
rigorous sampling protocols and QA/QC procedures (NCDWR 2013); organisms are identified by
highly trained biologists. Sampling for those assessments has typically been conducted every
five years. This site should be monitored on a 5‐year schedule to determine trends in the benthic
community as the WMP is implemented.
In 2013, the EQI SMIE program (EQI 2014) established three benthic macroinvertebrate sites in
the upper Swannanoa River watershed. Each site is sampled twice per year, spring and fall, using
trained volunteers (Figure 3 and Table 7; EQI 2014). While not quite as rigorous as the NCDWR
sample efforts, the higher frequency of SMIE sampling will provide a greater chance to detect
short‐term effects of watershed changes. The established sites should be sampled two times per
year throughout the life of the WMP. Where concentrations of projects are planned, it may be
necessary to establish monitoring sites at the catchment level.
Upper Swannanoa River Watershed Plan 95 January 2016
Town of Black Mountain, N.C.
Fish Community – The NCDWR does not have a fish community monitoring site within the upper
Swannanoa River watershed. A request to collect baseline
samples fall 2015 or spring 2016 could not be accommodated.
However, it is recommended that the NCDWR be asked to
establish at least one fish sample in 2016 (baseline), 2020, and
2025 for purposes of obtaining fish Index of Biotic Integrity
ratings. The sample should be taken at or near the existing
benthic macroinvertebrate site and conducted at the same
time as the benthic community sampling occurs.
Aquatic Habitat – As with the biological communities, the NCDWR also assesses aquatic habitats
following standard procedures (NCDWR 2013). It is recommended that an aquatic habitat
assessment be conducted concurrently with the fish and benthic community sampling. Habitat
assessments at these sites should be conducted on the same schedule as recommended for
biological communities.
Stewardship Monitoring
Stewardship is an important component of this WMP. All watershed improvements, be they
physical improvements, SCMs, riparian revegetation, or land conservation, require stewardship
to ensure that they are maintained and protected for the long term. This is necessary not only to
maintain their effectiveness but to protect the community’s investment in improving the
watershed. As management measures are
implemented throughout the watershed, it is necessary
to monitor them on a regular basis. Monitoring, in this
sense, will be to ensure that structures are functioning
properly, lands are being managed appropriately, and
encroachments into areas under legal protection (e.g.,
conservation easements) are not occurring. Ideally,
responsibility for these activities should be assigned to
a “Watershed Coordinator” that is a part of a local
organization or agency associated with the sponsor of
this plan.
Monitoring activities, frequencies, benchmark levels, and target levels have been developed and
are presented in Table 31. Benchmarks for fish and benthic macroinvertebrate communities and
aquatic habitat are based on metric scoring methods developed by the NCDWR and SMIE,
whereas water quality parameters are measured against NCDWR and USEPA standards
(NCDWR 2013).
Watershed stewardship ensures that
investments in watershed conservation
practices are protected and managed for
purposes of maintaining water quality,
wildlife habitat, and community
awareness.
Upper Swannanoa River Watershed Plan 96 January 2016
Town of Black Mountain, N.C.
Table 32. Watershed Monitoring Plan
Parameter Sites Frequency
or Years Benchmark Levels Target Levels
Water Chemistry
pH
Alkalinity
Turbidity
Total Suspended Solids
Conductivity
Nutrients
Orthophosphate
(PO43‐)
Ammonia‐Nitrogen
(NH4+/NH3)
Nitrate/Nitrite‐
Nitrogen (NO3‐/NO2‐)
Swannanoa River at
railroad bridge adjacent
to US 70 (VWIN)
Monthly Comparison with
historic data
Maintain Below State
Standards
Biological
Benthic
macroinvertebrate
community1
NCDWR monitoring site:
SR 2500, Blue Ridge
Road
2016, 2020,
2024
Comparison with
historic data
Good‐Fair or better
ratings based on
NCDWR IBI Scoring
Benthic
macroinvertebrate
community
SMIE Swannanoa R.
monitoring sites:
At Flat Creek
At Black Mountain
Recreation Park
At Kearfott Plant
Annually Comparison with
historic data
Good‐Fair or better
ratings based on SMIE
BI Scoring
Fish Community2 Establish NCDWR
monitoring site at
benthic location
Establish in
2016;
repeat in,
2020 and
2024
Comparison with
historic data
Establish baseline rating
Maintain Good‐Fair or
better rating (NCDWR
Fish IBI score ≥40)
Physical
Aquatic habitat At NCDWR benthic and
fish monitoring sites
2016, 2020,
2024
Comparison with
historic data
All sites with metric
scores ≥80
Stewardship
Project structures and
properties
Completed sites Annually Post‐project
conditions
Stream stability,
reduced erosion, no
encroachments
1This sampling effort has been discussed with NCDWR staff; however, no commitment to conduct it has been made as they do not
know if the resources will be available. A formal request for assistance should be made.
2NCDWR was not able to accommodate sampling in 2015; a follow‐up request will be necessary to obtain sampling in
2016.
Upper Swannanoa River Watershed Plan 97 January 2016
Town of Black Mountain, N.C.
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APPENDICES
Appendix A. Stormwater Assessment
Potential Project Identification
Preliminary Desktop GIS Analysis ‐ Opportunities for potential stormwater control measure
(SCM) projects were explored using a combination of GIS and field reconnaissance. Commercial,
institutional, and industrial land uses were identified. Those containing large expanses of
impervious surface and poor land use practices were flagged for field evaluation to assess
potential impacts and opportunities for SCMs. This analysis resulted in 28 potential SCM project
sites being identified. An additional three sites were provided by members of the stakeholder
group.
Field Assessment ‐ During the field assessment, observations were made on the land use draining
to the site, existing stormwater management practices, and site constraints to determine
whether SCMs are feasible. A field data form was completed for each site (Appendix Table A‐1)
and photographs taken to document existing conditions. If necessary, site sketches were made
of the site.
Data Analysis and Results – Field data were digitized for analysis. Of the 31 site assessed, 10 were
screened from further analysis due to constraints that would not allow them to be constructed
under current conditions. For the remaining 21 locations, the type of potential SCM was
identified. Conceptual plans were prepared for 13 of the sites. These plans depict the site,
stormwater flow patterns, type and location of SCM that may be possible.
Once the potential sites were identified, their constructability, benefit to stormwater
treatment/reduction, and public benefit and visibility were characterized as Favorable,
Moderately Favorable, or Unfavorable by the stakeholder group using a “traffic light” (green,
yellow, red) assessment procedure as recommended by NEMAC. The overall ratings were used
to determine the time period in which it would be likely that the project could be constructed
(Near‐term, 1‐3 years; Mid‐term, 4‐7 years, or Long‐term, 8‐10) over the life of the planning
document (Element F, Table 24).
Pollutant Load Reduction
An estimate of pollution reduction potential was calculated based on pollutant removal
efficiencies of the individual SCMs, the percent of impervious surfaces draining to each SCM, the
pollutant concentration in runoff based on land use, and the area of land draining to the SCM
using the SIMPLE method (Schueler 1987). It should be noted that the calculations in this model
are rough approximations of actual pollutant reductions. An in depth study of each site is
required to accurately estimate pollutant reductions. Results of this analysis are presented in
Element C.
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Town of Black Mountain, N.C.
Appendix Table A‐1. Stormwater Control Measure Site Evaluation Form
Subwatershed: __________ BMP (desktop) ID Type: __________ Staff:_________________
Date___________________ Site Location (Road):_____________________________________________
Tracking Information
Waypoint ___________ Lat_______________________ Long_______________________
Photo number(s) and description________________________________________________________________
Reason for Assessment (check one; describe if further details are deemed appropriate)
Large developed area (e.g. mall, large strip development, industrial complex, large mixed use area)
___________________________________________________________________________________________
Large area of land clearing or disturbance (note nature if
obvious)____________________________________________
Pollution potential (list if any are observed, e.g. storage tanks, trash receptors, etc.)
_________________________________________________________________________________________
Nature of Site
Name of Facility/Area (if obvious)_____________________________________________________________
(Check all that apply)
Commercial Gov’t Pasture Land disturbance Institutional
Transport-related Row crops Animal operation Other____________ Industrial
Golf course Nursery Residential
Site Concerns (check all that apply):
Developed uses:
Vehicle Operations (circle): Fueled Washed Maintained Repaired Stored Sold None No
Observation
Uncovered Outdoor Material Storage: Yes No Unknown No Observation
Describe: _________________________________________________________
Waste Management: Garbage Construction Hazardous None Other__________ No Observation
Dumpsters: Leaking Near storm drain OK No Observation
Impervious Surface Condition: Clean Stained Debris/Dirty Breaking Up No Observation
Other___________________________________________________________
Impervious Surface Size: <1 acre 1-5 acres 5-10 acres >10 acres
Type of impervious surface: Parking lot Rooftop Roadway Other…
Open space between outfall and property boundary
Area drains directly to storm sewers
Area drains directly to adjacent property
Area in immediate proximity to stream or drainageway (with / with no controls)-circle one
Site Constraints:
Possible conflicts with other site functions (e.g., traffic flow) No Yes
(describe)_______________________________________________________________________________
Conflicts with existing utilities None
Yes Possible
Sewer
Water
Gas
Electric
Overhead utilities
Other__________________________________
Access Constraints (construction and maintenance) No Yes (describe-slopes, structures)
Possible Conflicts with Adjacent Land Use No Yes
describe)___________________________________________
ST Potential1 2 3 4 5 6 7 8-specifically Other-explain on back
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Town of Black Mountain, N.C.
Appendix B. Riparian Area Assessment
Potential Project Identification
The primary objective of the riparian area analysis was to assess the general condition of
vegetation in the corridor of land near and adjacent to streams. Vegetated, woody riparian areas
of less than 30 feet in width from the tops of both stream banks and have been documented as
too narrow to effectively filter sediment, nutrients, and fecal coliform bacteria. It is also
documented that riparian zones help stabilize stream banks and slow stream bank erosion. The
identification of potential stream improvement projects in the USRW was completed entirely by
using GIS.
This analysis included all streams within the USRW. These potential riparian sites were identified
using NC OneMap’s 2010 Orthoimagery (NCCGIA 2011) provided by the State of North Carolina.
Healthy vegetated riparian areas were defined as areas that were predominantly forested over
the entire riparian area. Streams were identified by using the North Carolina Stream Mapping
Program (NCSMP) GIS stream data layer based on 2007 LiDAR data (NCGIA Undated), a 60‐foot
buffer was generated and centered on each stream line (30 feet to either side of the stream)
within the study area. Starting at each downstream line segment of and moving upstream,
imagery were visually examined and each stream segment in the GIS stream dataset were
analyzed in determination for good potential for a riparian restoration project. Land use
classification was also taken into account (Appendix Table B‐1). In an attempt to maintain
consistency, this imagery were initially examined at 1:1000, zooming in if necessary to verify
classification. The NC Onemap 2010 orthoimagery in the USRW is “leaf‐off”; in some cases
making identification of forested areas difficult. When necessary, additional imagery was used ‐
‐ primarily ESRI World Imagery (ESRI 2015) ‐‐ in order to verify the presence of, “leaf‐on” forested
areas within the buffer. Quality control was performed by a second staff member who examined
and verified imagery and good riparian restoration potential classifications at a 1:3000 scale.
Stream reaches with riparian zones having widths of less than 30 feet (from top of one or both
stream banks) and greater than 500 feet in length were identified as potential stream
improvement projects. In addition to riparian vegetation condition, whether or not the stream
had been channelized or otherwise straightened and the relative extent of entrenchment also
were characterized to the extent possible from the aerial photos. No field surveys of these sites
were made. No parcel ownership analysis was conducted other that identifying public vs. private
lands. Due to the inherent subjectivity associated with visual analysis of aerial imagery, these
data should be viewed as being a screening tool for site identification. Further assessment will
be necessary to determine on the ground conditions; landowner outreach must be a part of that
effort.
Lengths of sites with good riparian area restoration potential were individually calculated for
each potential site. Output from the GIS dataset was exported to a Microsoft Excel® format for
further analysis. A total of 5.86 miles (30,958 feet) of stream at 16 location were identified as
having good potential for improvement. Of those sites, 61% of the total stream lengths are
either Tomahawk Branch or tributaries to Tomahawk Branch. Four locations show signs of
channelization or significant entrenchment; two of those sites are in the Tomahawk Branch
subwatershed. Results of this analysis are presented in the section titled Potential Stream
Improvement Projects.
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Town of Black Mountain, N.C.
Pollutant Load Reduction Modeling
Sediment loads related to streambank erosion were modeled using data collected by visually
analyzing remotely sensed images and the USEPA’s Spreadsheet Tool for the Estimation of
Pollutant Load (STEPL) model. The STEPL model is comprised of a spreadsheet that uses simple
algorithms to calculate nutrient and sediment loads. For purposes of this WMP, STEPL was used
to estimate annual sediment load contributed from streambank erosion, based on estimated
bank condition and length of eroding bank, and the potential load reductions if banks were
stabilized (Appendix Table B‐1). Technical information regarding calculations of sediment
loading can be found in the STEPL User’s Guide (USEPA 2006).
The required STEPL model inputs include length of bank (feet), height of bank (feet), rate of
lateral recession (feet per year), efficiency of the stream improvement measure, and soil textural
class. A separate model was run for each site. Within each model, the values were partitioned
by potential project reach. Based on a “heads up” process stream widths were measured using
2015 aerial imagery. Bank heights were estimated by determining a statistical relationship
between banks full widths and bankfull heights from observed published data (Harman et al.
2000). The bankfull heights were estimated using the regression equation: y= 0.0282x + 1.2288.
Where Y equals the estimated bankfull height and X equals the observed bankfull width. These
bank height estimates were then used in the model for each identified reach. Identified higher,
more entrenched, channel bank heights were multiplied by 1.5 the modeled height. Reach
lengths were doubled to account for both the right and left bank lengths within the STEPL model.
Bank stability score for each site was used to determine the lateral recession rate. All sites were
categorized as having moderate recession rates except for sites with obvious entrenched reaches
and/or land use that indicate adjacent impervious surfaces, which were categorized as severe. In
these instances the recession rates were considered severe. The STEPL model categorizes
lateral recession into four categories with:
• Slight ‐ Some bare bank but active erosion not readily apparent. Some rills but no
vegetative overhang. No exposed tree roots.
• Moderate ‐ Bank is predominantly bare, with some rills and vegetative overhang.
• Severe ‐ Bank is bare, with rills and severe vegetative overhang. Many exposed tree roots
and some fallen trees and slumps or slips. Some changes in cultural features, such as
fence corners missing and realignment of roads or trails. Channel cross‐section becomes
more U‐shaped as opposed to V‐shaped.
• Very Severe ‐ Bank is bare, with gullies and severe vegetative overhang. Many fallen
trees, drains, and culverts eroding out and changes in cultural features as above.
Massive slips or washouts common. Channel cross‐section is U‐shaped and the
streamcourse or gully may be meandering.
Only stream bank improvements were included in the model. Pollutant removal, expressed as
percent removal of the targeted pollutants present, is required to estimate the total pollutant load
reduction to be achieved. In this case, it is the reduction in sediment due to bank stabilization. Some
level of background erosion is present in any natural stream system; however, erosion will be
significantly less than that of an impacted stream system. For this model, we used an efficiency of
80% to account for “natural” background erosion even with a successful project. The last input for
the STEPL model is soil textural class, which can greatly affect the amount of soil loss due to
differences in cohesion. A review of Natural Resources Conservation Service (NRCS) soil survey data
Upper Swannanoa River Watershed Plan 107 January 2016
Town of Black Mountain, N.C.
indicated that most of the study area consisted of a mixture of loams and sandy clay loams. The
results of the load reduction model are presented Element C.
Appendix Table B‐1. Stream Improvement Project Migration Rates
Site
Number Location Description
Stream
Channel
Length
(feet)
Migration
Rate
Observed Site Condition
based on NLCD
Classification
1 Tomahawk Branch 7,457 Severe 100% developed open pace
2 Tomahawk Branch 3,318 Moderate
60% agricultural
10% developed open space
3 Walker Cove Road 991 Moderate
30% agricultural
10% developed open space
4 Tomahawk Branch 1,844 Moderate
30% developed open space
10% agricultural
5 Assembly Drive 502 Moderate 100% developed open space
6 Flatt Creek 692 Moderate 100% developed open space
7 Avena Road 1,544 Severe 80% developed open space
8 Mountain View Avenue 1,638 Moderate
70% developed open space
10% low intensity developed
9 Tomahawk Branch 2,896 Severe 100% developed open space
10 Old Toll Circle 1,020 Severe 80% developed open space
11 Frances Avenue 761 Moderate
50% developed open space
50% agricultural
12 Hospital Road 1,458 Severe
80% developed open space
10% agricultural
13 Tabernacle Road 1,335 Moderate
60% agricultural
10% developed open space
14 Armory Road 2,367 Moderate
50% agricultural
20% developed open space
15 Llama Vista Court 844 Moderate 80% developed open space
16 Chapel Road 2,291 Severe 100% developed open space
Totals 30,958
1Site condition is based on the National Land Cover Database classifications.