20001195 Ver 17_More Info Received_20200810

Strickland, Bev
From: Thames, Kelly <[e-mail]>
Sent: Monday, August 10, 2020 11:38 AM
To: Homewood, Sue
Subject: RE: [External] CLT Airport Public Notice Response
Attachments: AppendixE_Proposed Monitoring Plan_2020804.docx
Follow Up Flag: Follow up
Flag Status: Flagged
I. Do not click links 2L pen attachments unless you verify. Send all suspicious email as an attachment to
Sue,
Please see the attached. The airport has signed off on this version.
Thanks!
Kelly
Kelly Thames, Pws
D 704.338.6710 M 704.996.9986
hdrinc.com/follow-us
From: Homewood, Sue [mailto:[e-mail]]
Sent: Thursday, August 6, 2020 3:34 PM
To: Thames, Kelly <[e-mail]>
Subject: RE: [External] CLT Airport Public Notice Response
CAUTION: [EXTERNAL] This email originated from outside of the organization. Do not click links or open attachments
unless you recognize the sender and know the content is safe.
Gotcha. Happy almost the weekend!
Sue Homewood
Division of Water Resources, Winston Salem Regional Office
Department of Environmental Quality
336 776 9693 office
336 813 1863 mobile
Sue. [e-mail]
450 W. Hanes Mill Rd, Suite 300
Winston Salem NC 27105
.:...,J.. t.£ t a ...
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1

From: Thames, Kelly <[e-mail]>
Sent: Thursday, August 6, 2020 3:31 PM
To: Homewood, Sue <[e-mail]>
Subject: RE: [External] CLT Airport Public Notice Response
External email. Do not click links or open attachments unless you verify. Send all suspicious email as an attachment to
I will. It's in the Airport's court right now. I will forward once I hear back!
Thanks,
Kelly Thames, Pws
D 704.338.6710 M 704.996.9986
hdrinc.com/follow-us
From: Homewood, Sue [mailto:[e-mail]]
Sent: Thursday, August 6, 2020 2:29 PM
To: Thames, Kelly <[e-mail]>
Subject: RE: [External] CLT Airport Public Notice Response
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unless you recognize the sender and know the content is safe.
Hi. Confirming that you should go ahead and update and resend. I'm going to work up some conditions for the 401 and
will send you a draft since they'll be unique.
Sue Homewood
Division of Water Resources, Winston Salem Regional Office
Department of Environmental Quality
336 776 9693 office
336 813 1863 mobile
Sue. [e-mail]
450 W. Hanes Mill Rd, Suite 300
Winston Salem NC 27105
et
r.
..l£:# ..
From: Thames, Kelly <[e-mail]>
Sent: Tuesday, August 4, 2020 3:41 PM
To: Homewood, Sue <[e-mail]>
Subject: RE: [External] CLT Airport Public Notice Response
9 &@nL.gov
xternal email. Do not click links or open attachments unless you verify. Send all suspicious email as an attachment to
Also the 2-year event is defined as 2.28 inches in 6 continuous hours and the 10-year is 3.72 inches in 6 continuous
hours.

The 2-year event was defined incorrectly in the monitoring plan 4 1 blame the PE! O
That being said .... can I revise the monitoring plan with the below clarification and the above rain event definition to send
you final copy? Or would you like me to wait a bit?
Thanks,
Kelly
Kelly Thames, Pws
D 704.338.6710 M 704.996.9986
hdrinc.com/follow-us
From: Homewood, Sue [mailto:[e-mail]]
Sent: Tuesday, August 4, 2020 3:28 PM
To: Thames, Kelly <[e-mail]>
Subject: RE: [External] CLT Airport Public Notice Response
CAUTION: [EXTERNAL] This email originated from outside of the organization. Do not click links or open attachments
unless you recognize the sender and know the content is safe.
Yes, that's perfect, thanks Kelly.
I don't think there's anything else but I'm still working through some of it with Olivia just to be sure I'm not missing
something she feels super strong about. I'll be in the field the next couple days but hopefully will be able to start
working on drafting the 401 soon.
Sue Homewood
Division of Water Resources, Winston Salem Regional Office
Department of Environmental Quality
336 776 9693 office
336 813 1863 mobile
Sue. [e-mail]
450 W. Hanes Mill Rd, Suite 300
Winston Salem NC 27105
F. ,. F.. F: .. h .,,* x .. # t „r ix.. : x...a i, r :ix *. )d
..# '' .. ¢.,#w.. t.,,,,.h :Le .,: € .=. .a ..#� _ £} +r ,,,.t# ,* h =fix ,
From: Thames, Kelly <[e-mail]>
Sent: Tuesday, August 4, 2020 3:18 PM
To: Homewood, Sue <[e-mail]>
Subject: RE: [External] CLT Airport Public Notice Response
External email. Do not click links or open attachments unless you verify. Send all suspicious email as an attachment to
[e-mail]
Sue,

I assume you mean that the monitoring will take place within 30 days of a 2-year storm event or greater? Correct.
Do you think we could add a caveat that the airport will monitor post larger storm event at least 1x per year? We'd
don't want each quarter to be a 2-year storm and miss any 10, 25, or more events. Yes, I don't think that would be a
problem.
See the table below — is this adequate? Note that the annual monitoring event of a larger storm (10+ year event) could
be additional to quarterly events or become the quarterly event, depending on the timing.
Monitoring Events
Storm Event
Notes
Pre -Construction
n/a
Would occur regardless of storm event
Post -Construction
n/a
Annual
n/a
Annual
10-year or greater
Would occur the 1st time a 10+ year event occurs in a year. Could
occur additional to the 4 quarterly events. Could be equal to a
quarterly event and take the place of a quarterly event. If no 10+ year
storms occur in a year, then this event would not take place in the
year.
Quarterly
2-yr or greater,
Would only occur if 2+ year storm event occurs in a quarter. If no 2+
whichever comes 1st
year storms occur in a quarter, then no monitoring in that quarter
in a quarter
would occur.
Let me know if you agree, and I will let the airport know.
Any other issues with the monitoring plan? Or will the above satisfy?
Call me if you want to talk it though.
Thanks,
Kelly
Kelly Thames, Pws
D 704.338.6710 M 704.996.9986
hdrinc.com/follow-us
From: Homewood, Sue [mailto:[e-mail]]
Sent: Tuesday, August 4, 2020 10:50 AM
To: Thames, Kelly <[e-mail]>
Subject: RE: [External] CLT Airport Public Notice Response
CAUTION: [EXTERNAL] This email originated from outside of the organization. Do not click links or open attachments
unless you recognize the sender and know the content is safe.
Hi Kelly,
I'm working on reviewing this (also still talking internally so it takes a little time back/forth). One quick question: For the
post storm event monitoring. I assume you mean that the monitoring will take place within 30 days of a 2-year storm
event or greater? So if there's a 25 year storm event as the first event in a quarter it would be monitored? Do you think
we could add a caveat that the airport will monitor post larger storm event at least 1x per year? We'd don't want each
quarter to be a 2-year storm and miss any 10, 25, or more events. We'd like to know if those larger events are different
than a 2-year event.
Thanks

Sue Homewood
Division of Water Resources, Winston Salem Regional Office
Department of Environmental Quality
336 776 9693 office
336 813 1863 mobile
Sue. [e-mail]
450 W. Hanes Mill Rd, Suite 300
Winston Salem NC 27105
# ° *... m Y k # x.. *v. x w' .. ,,,, .".:.Y # .v. #' x s ::} }'"%. 11 "} '*xa
From: Thames, Kelly <[e-mail]>
Sent: Thursday, July 23, 2020 6:28 PM
To: Homewood, Sue <[e-mail]>
Subject: RE: [External] CLT Airport Public Notice Response
External email. Do not click links or open attachments unless you verify. Send all suspicious email as an attachment to
[e-mail]
Sue,
Please find attached the revised monitoring plan in word format in case you'd like to add comments easier.
Don't hesitate to reach out to discuss further or if you have any clarifying questions you'd like me to answer.
Thanks!
Kelly
Kelly Thames, Pws
D 704.338.6710 M 704.996.9986
hdrinc.com/follow-us
From: Homewood, Sue [mailto:[e-mail]]
Sent: Monday, July 13, 2020 8:28 AM
To: Thames, Kelly <[e-mail]>
Cc: Geiger, Ronald A. <[e-mail]>
Subject: RE: [External] CLT Airport Public Notice Response
CAUTION: [EXTERNAL] This email originated from outside of the organization. Do not click links or open attachments
unless you recognize the sender and know the content is safe.
Thank you Kelly,
I will consider the application on hold until receipt of the updated monitoring plan.
Sue Homewood
Division of Water Resources, Winston Salem Regional Office
Department of Environmental Quality
5

336 776 9693 office
336 813 1863 mobile
[e-mail]
450 W. Hanes Mill Rd, Suite 300
Winston Salem NC 27105
From: Thames, Kelly <[e-mail]>
Sent: Monday, July 13, 2020 7:47 AM
To: Homewood, Sue <[e-mail]>
Cc: Geiger, Ronald A. <[e-mail]>
Subject: RE: [External] CLT Airport Public Notice Response
A External emai en attachment Send all sail as an attachment to
@
Hi Sue,
Thanks for talking with us last week about the Airport and some of your additional concerns regarding the detention
basins.
We've been able to loop in the airport and I am currently revising the plan with the goal of providing it to the airport later
this week or early next week. We want to make sure they are comfortable with the commitment and to begin the process
of training and/or identifying a resource that can assist them with the monitoring.
Once we have their buyoff, I will provide to you for review.
Thanks!
Kelly
Kelly Thames, Pws
D 704.338.6710 M 704.996.9986
hdrinc.com/follow-us ihdrinc.coml
From: Thames, Kelly
Sent: Thursday, July 2, 2020 9:08 AM
To:'Homewood, Sue' <[e-mail]>
Cc: 'Shaeffer, David Leigh (Dave) CIV USARMY CESAW (USA)' <[e-mail]>
Subject: RE: [External] CLT Airport Public Notice Response
Ok, thank you, just let me know what I can do!
Kelly Thames, Pws
D 704.338.6710 M 704.996.9986
hdrinc.com/follow-us fhdrinc.coml
From: Homewood, Sue [mailto:[e-mail]]
Sent: Thursday, July 2, 2020 9:04 AM
To: Thames, Kelly <[e-mail]>

Cc: 'Shaeffer, David Leigh (Dave) CIV USARMY CESAW (USA)' <[e-mail]>
Subject: RE: [External] CLT Airport Public Notice Response
CAUTION: [EXTERNAL] This email originated from outside of the organization. Do not click links or open attachments
unless you recognize the sender and know the content is safe.
Hi Kelly,
I wanted to let you know that I reviewed your addinfo response but I need to follow up with Olivia and I want to talk to
David before I get back to you.
Sue Homewood
Division of Water Resources, Winston Salem Regional Office
Department of Environmental Quality
336 776 9693 office
336 813 1863 mobile
Sue. [e-mail]
450 W. Hanes Mill Rd, Suite 300
Winston Salem NC 27105
.#:,t.x°;.
From: Homewood, Sue <[e-mail]>
Sent: Monday, June 29, 2020 10:04 PM
To: Thames, Kelly <[e-mail]>
Cc: 'Shaeffer, David Leigh (Dave) CIV USARMY CESAW (USA)' <[e-mail]>
Subject: Re: [External] CLT Airport Public Notice Response
Sorry. My schedule was derailed by rule re -writes that I didn't know would need my involvement last week. I'm trying to
get back on track this week but have meetings and piles of emails.
Get Outlook for iOS[naml2.safelinks.protection.outlook.com1
From: Thames, Kelly <[e-mail]>
Sent: Monday, June 29, 2020 9:48:12 AM
To: Homewood, Sue <[e-mail]>
Cc: 'Shaeffer, David Leigh (Dave) CIV USARMY CESAW (USA)' <[e-mail]>
Subject: RE: [External] CLT Airport Public Notice Response
nal email. Do not click links or openachments email as an attachment to
Sue,
Let me know about the below when you get to it. Dave reviewed the response and doesn't have any objections. The next
step is for me to update his EA with the information in the response.
However, I don't want to begin until we've heard from you!

Thanks,
Kelly
Kelly Thames, Pws
D 704.338.6710 M 704.996.9986
hdrinc.corn follow -us ihdrinc.coml inam12.safelinks. protection. outlook.coml
From: Thames, Kelly
Sent: Friday, June 19, 2020 8:06 AM
To:'Homewood, Sue' <[e-mail]>
Subject: RE: [External] CLT Airport Public Notice Response
Thanks for the update!
Kelly Thames, Pws
D 704.338.6710 M 704.996.9986
hdrinc.corn follow -us fhdrinc.coml fnam12.safelinks.protection.outlook.coml
From: Homewood, Sue [mailto:[e-mail]]
Sent: Thursday, June 18, 2020 1:20 PM
To: Thames, Kelly <[e-mail]>
Subject: RE: [External] CLT Airport Public Notice Response
CAUTION: [EXTERNAL] This email originated from outside of the organization. Do not click links or open attachments
unless you recognize the sender and know the content is safe.
Hi. It's next on my review list but I have some other commitments to finish up right now. I expect I'll get a chance to
look at it sometime next week.
Sue Homewood
Division of Water Resources, Winston Salem Regional Office
Department of Environmental Quality
336 776 9693 office
336 813 1863 mobile
Sue. [e-mail]
450 W. Hanes Mill Rd, Suite 300
Winston Salem NC 27105
From: Thames, Kelly <[e-mail]>
Sent: Thursday, June 18, 2020 1:08 PM
To: Homewood, Sue <[e-mail]>
Cc:'Shaeffer, David Leigh (Dave) CIV USARMYCESAW (USA)' <[e-mail]>
Subject: [External] CLT Airport Public Notice Response
External email. Do not click links or open attachments unless you verify. Send all suspicious email as an attachment to
[e-mail]
R

Hi Sue,
I wanted to check in and see if you had any questions or comments regarding the public notice response for the Airport?
My goal is to stay on top of it for the Airport's schedule!
Thanks!
Kelly Thames, Pws
Environmental Project Manager
HDR
440 S. Church Street, Suite 1000
Charlotte, NC 28202-2075
D 704.338.6710 M 704.996.9986
kelly.thames(a)_hdrinc.com
hdrinc.com/follow-us fhdrinc.coml fnaml2.safelinks.protection.outlook.coml fnaml2.safelinks.protection.outlook.coml

Appendix E
Monitoring Plan

CLT Airport Expansion I SAW-2018-01071
In -Line Detention Monitoring Plan
August 4, 2020
Proposed Monitoring Plan
Introduction
The City of Charlotte — Aviation Department (Applicant) submitted a Department of the Army Phased
Individual Permit (IP) on January 31, 2020, for the proposed expansion of the Charlotte Douglas
International Airport (CLT or Airport) in Mecklenburg County, North Carolina. A component of the Phased
I proposes stormwater detention in -line with existing channels. During the Public Notice period, the
United States Army Corps of Engineers (USACE) and the North Carolina Department of Environmental
Quality (NCDEQ) Division of Water Resources (DWR) requested a monitoring plan of those channels
subject to in -line detention.
In the application, in -line detentions are proposed on Ticer Branch (Stream 1 [S1]) for the North End
Around Taxiway (NEAT) element and on Coffey Creek (S25) for the South Crossfield Taxiway (SCF)
element. The purpose of an in -line detention is to provide peak discharge reduction for storm events up to
the 100 year event. Both in -line detentions propose permanent impacts as a result of a culvert and berm
that would be sized to reduce peak flows downstream. For purposes of analysis storm frequencies
modeled include the 2-, 10-, 25-, 50-, and 100-year storm events. Additionally, each detention basin also
proposes a culverted stream crossing for road access within a basin for construction and maintenance.
During the design storm event, the streams would overtop their banks and flood the detention area (i.e.
the stream's floodplain) for stormwater detention, but attenuate within 48 hours. Beyond the culvert and
berm and access road culvert in each basin, no other direct impacts as a result of the in -line detention are
proposed to the stream channels. However, the streamside areas of both Ticer Branch and Coffey Creek
would require an earthen embankment, grading, and removal of trees in order to provide the capacity
necessary to detain the designed storm event. A 10-foot vegetated buffer along each stream will be
maintained.
In the Ticer Branch in -line detention, S1 and S2 are proposed to experience flooding of streamside area.
In the Coffey Creek in -line detention, S25, S32, and S34 are proposed to experience flooding of
streamside area. All five channels will require monitoring per the USACE and DWR request.
Monitoring Locations
The location and number of monitoring locations within both the Ticer Branch and Coffey Creek detention
areas and one monitoring location downstream of each detention basin will be identified. These locations
will be submitted to the DWR prior to baseline monitoring implementation. For the Ticer Branch detention
basin, one location will be located downstream of the detention, but before Ticer Branch enters a culvert
that goes beneath 1-485. For the Coffey Creek detention basin, one location will be downstream of the
detention but upstream of the next downstream stream confluence. Permanent monitoring locations will
be field located using GPS grade accuracy, and set prior to construction by setting permanent
monuments on both stream banks to facilitate comparison of data collected during future monitoring
events.
Monitoring locations within the detention basins will be subject to dimension, substrate, Bank Erosion
Hazard Index (BEHI), and North Carolina Stream Assessment Methodology (NCSAM) assessments, as
well as photographic documentation. Monitoring locations downstream of the detention basins will be
subject to substrate and BEHI assessments, as well as photographic documentation.
Page 1 1

CLT Airport Expansion I SAW-2018-01071
In -Line Detention Monitoring Plan
August 4, 2020
All monitoring locations are subject to baseline pre- and post -construction events. The monitoring
locations within the detention basins will be subject to both the annual and quarterly monitoring events.
The monitoring locations downstream of the detention basins will be monitored on a quarterly basis only,
within 30 days of a 2-year storm event or greater (a 2-year storm defined as a rain event of at least 2.28
inches within 6 continuous hours). A storm event greater than the 2-year is a 10-year or greater storm (a
10-year storm defined as a rain event of at least 3.72 inches within 6 continuous hours).
Timing/Frequency
BASELINE MONITORING
The baseline monitoring events will take place pre -construction and post -construction. The purpose of the
pre -construction event is to capture existing conditions of streams subject to detention. The post -
construction event is to document any changes between pre -construction and post -construction and
construction conditions; ideally, the post -construction conditions of streams would be the same as
existing conditions pre -construction with the exception of the streamside areas being converted to
detention areas. If a 2-year storm occurs between the pre -construction and post -construction events, it
should be documented and noted that the post -construction baseline would capture any changes from
said storm event prior to the detentions becoming operational. The data collected immediately following
construction would be expected to be representative of conditions that subsequent monitoring events
would be compared to, taking into account normal stream dynamics and fluctuation.
Baseline monitoring event data collection will include dimension, substrate, Bank Erosion Hazard Index
(BEHI), and NCSAM assessments, as well as photographic documentation.
ANNUAL MONITORING
Annual monitoring events will be held on an annual basis for a period of five years post -construction of
both the Ticer Branch and the Coffey Creek detention basins. This annual monitoring will occur
regardless of storm event occurrence. The first annual monitoring event shall occur six months after the
post -construction baseline event occurs. If at the end of the five year period of monitoring, the results
during the monitoring events have not significantly changed since the post -construction baseline
condition, then the annual monitoring requirements shall be successfully satisfied.
Annual monitoring event data collection will include dimension, substrate, Bank Erosion Hazard Index
(BEHI), and NCSAM assessments, as well as photographic documentation at locations within the
detention basins.
ANNUAL MONITORING POST -STORM
Annually, monitoring shall occur within 30 days following the first 10-year storm event or greater for a
period of five years post -construction of both the Ticer Branch and the Coffey Creek detention basins.
Only one annual monitoring event per 10-year or greater storm event is necessary. This post -storm
annual monitoring event could be additional to quarterly events or become the quarterly event, depending
on storm frequency timing.
Post -storm annual monitoring event data collection will include substrate and BEHI assessments, as well
as photographic documentation at locations within the detention basins and downstream of the detention
basins.
QUARTERLY MONITORING
On a quarterly basis, monitoring shall occur within 30 days following the first 2-year storm event or greater
(2-year+) of the respective quarter up to two years. Only one monitoring event per quarter per 2-year+
storm event is necessary. If a 2-year+ storm event does not occur, then monitoring during that respective
Page 12

FN
CLT Airport Expansion I SAW-2018-01071
In -Line Detention Monitoring Plan
August 4, 2020
quarter is not required. If at the end of the two year period of quarterly monitoring, the results during the
monitoring events have not significantly changed since the post -construction baseline condition, then the
quarterly monitoring requirements shall be successfully satisfied.
Quarterly monitoring event data collection will include substrate and BEHI assessments, as well as
photographic documentation.
Table 1. Summary of Monitoring Requirements
or ring
Requirements
Within
Dimension,
Pre -Construction
1 time
detention
substrate, BEHI,
n/a
basins
NCSAM, photos
Within
Dimension,
Conducted regardless of storm
Post -Construction 1 time
detention
substrate, BEHI,
n/a
basins
NCSAM, photos
event.
1x/year for
Within
Dimension,
Annual
5 years
detention
substrate, BEHI,
n/a
basins
NCSAM, photos
Conducted the 111 time a 10-
year+ event occurs in a year.
Within and
Could occur additional to the 4
Annual
1x/year for
downstream
Substrate, BEHI,
10-year or
quarterly events or could be
(Post -Storm)
5 years
of detention
photos
greater
equal to and take the place of
basins
a quarterly event. If no 10-
year+ storms occur in a year,
then annual monitoring post -
storm would not occur.
2-year or
Would only be conducted if a
Downstream
greater,
2-year+ storm event occurs in
Quarterly
4x/year for
of detention
Substrate, BEHI,
whichever
a quarter. If no 2-year+ storms
(Post -Storm)
2 years
basins
photos
comes 111
occur in a quarter, then
in a
monitoring in that quarter
quarter
would not occur.
Methods
DIMENSION ASSESSMENT
Dimensional data will be collected based on The Key to the Rosgen Stream Classification of Natural
Rivers which is a classification system that assigns a channel type based on channel slope, width to
depth ratio, bed material, entrenchment ratio, and sinuosity. Permanent cross section monitoring will be
conducted at one or more riffle features that are established during the baseline monitoring events on
each channel subject to in -line detention. A stream classification type will be determined at each cross
section during the baseline events as well as subsequent monitoring events. Graphical representations of
cross sections will be provided and as data is collected year to year, the graphical representations will be
overlaid to each other for comparison.
Data collected in dimensional assessment will be presented as a list of parameters (Table 1) resulting in a
Rosgen Classification channel type, which represents the measure of all dimension assessment
parameters. Classifying a channel type based on Rosgen methodology on an annual basis allows for
observation in shifts of channel geomorphology, if any. Geomorphological evolution is a natural channel
Page 13

CLT Airport Expansion I SAW-2018-01071
In -Line Detention Monitoring Plan
August 4, 2020
process, that when observed, doesn't necessarily indicate channel degradation, but does provide insight
as to whether or not a channel is widening, incising, straightening, or experiencing sediment loading
based on the measured parameters.
The Rosgen Classification channel type is not expected to significantly change from baseline conditions;
however, if channel type changes do occur, then it would be expected that one or more parameter has
significantly been altered from the baseline channel classification type. Further analysis of the individual
parameters (i.e. substrate) would need to be evaluated to determine if degradation has occurred.
SUBSTRATE
A Wolman pebble count is a characterization of the composition of streambed and bank substrate
material. Monitoring substrate during monitoring events can indicate changes in stream character, erosion
rates, and sediment supply. Wolman pebble counts categorize substrate types into silt/clay, sands,
gravels, cobbles, boulders, and bedrock, which are sub -categorized within the substrate types based on
diameter size. The data collected from a substrate sample can be analyzed by sizes (diameter in mm)
and by distribution of size. For example, D50 is the median diameter of a substrate sample and also the
diameter size at which 50% of the substrate particles are smaller and 50% of the substrate particles are
larger than the mean diameter distributed across a sample.
Wolman pebble count methodology will be utilized to calculate the D50 of the stream bed material to
establish baseline particle size and distribution at the permanent cross -sections to aid in determining
Rosgen classification channel type. The post -construction baseline D50 will also be the parameter to
which future substrate analysis would be compared. If future substrate monitoring indicates a trend of the
D50 shifting to a smaller particle size diameter (by more than 20% of original size) after three substrate
monitoring events, then DWR will be notified and remedial actions will be evaluated for consideration.
BANK EROSION HAZARD INDEX
While stream bank erosion is a natural process that occurs in every watershed, excessive erosion has
serious adverse consequences for the physical and biological function of streams and rivers. It is often
difficult, however, to distinguish between streambanks that are eroding at a natural rate from those that
are or have the potential to erode at unnaturally high rates due to altered watershed hydrology or
sediment loads. The Bank Erosion Hazard Index (BEHI) is a methodology for assessing streambank
erosion condition and potential that assigns point values to bank condition. BEHI will be assessed utilizing
the modified BEHI procedure that includes ratios of root depth to bank height, root density in percentage,
surface protection in percent, and bank angle in degrees.
The BEHI scoring falls into six categories ranging from Very Low to Extreme. In reference to the post -
construction baseline BEHI scores, if future monitoring events produce a BEHI score two categories
greater than the baseline from three subsequent events, then DWR will be notified and remedial actions
will be evaluated for consideration. DWR will be contacted if the baseline score is "Extreme", for further
discussion and possible procedure modification.
NORTH CAROLINA STREAM ASSESSMENT METHODOLOGY
The North Carolina Stream Assessment Methodology (NCSAM) will be utilized to assess stream quality
and function at each cross section. The assessment length at each cross section will be 100 feet
upstream and downstream of the cross section location. The NCSAM method provides for an evaluation
of streamside riparian vegetation as well as a field assessment of hydrological influence, water quality,
and biology within a reach. However, due to the nature of the detention construction, the streamside
areas will be cleared of trees with the exception of a 10-foot vegetated buffer. The NCSAM assessments
Page 14

CLT Airport Expansion I SAW-2018-01071
In -Line Detention Monitoring Plan
August 4, 2020
should take into consideration the NCSAM matrices that assess vegetated buffer parameters so that the
detention construction itself does not influence the NCSAM scores.
PHOTOGRAPHIC DOCUMENTATION
Photographs looking upstream and downstream at each monitoring location will be taken during the
baseline monitoring to visually document the existing conditions of the channels. Photographs will also be
taken post -construction, and at annual and quarterly monitoring events. Photographs will be provided in
both the annual and quarterly reports, but will also be displayed side by side over time as the
photographs are collected.
Summary
The proposed monitoring plan for the channels subject to in -line detention will consist of multiple
measurements and assessments noted above that will provide a way to track the geomorphology,
substrate, stability, and quality of the channels over time. Pre- and post -construction baseline conditions
will be presented with a short cover letter and report of findings will be provided to the USACE and DWR
for review. Subsequently, after each annual and quarterly monitoring event, a short cover letter and report
of findings will be provided for review.
At each cross section identified within the detention basins, dimensional data, substrate characterization,
NCSAM, BEHI will be assessed and described above. A variation of the following table will be utilized to
report baseline, annual, and quarterly data at each cross-section. At each monitoring location identified
downstream of the detention basins, substrate characterization and BEHI will be assessed and described
above.
Table 2. Example Table for Assessment Data
Stream #
Cross Section #
Bankfull Width (ft)
Floodprone Width (ft)
Bankfull Mean Depth (ft)
Bankfull Max Depth (ft)
Bankfull Cross Sectional Area (ft2)
Width/Depth Ratio
Entrenchment Ratio
D5o (mm)
Rosgen Classification
NCSAM Score
BEHI
Stream # Stream #
Cross Section # Cross Section #
A variation of the following table will be utilized to report overall data after each collection event over time.
Table 3. Example Table of Results Summary
Om
RClassn D5o NCSAM BEHI RClassn D5o NCSAM BEHI
Stream # #
Stream # #
Stream # #
Stream # #
Page 15
Rosgen D5o NCSAM BEHI
Class

M
Methodology References
CLT Airport Expansion I SAW-2018-01071
In -Line Detention Monitoring Plan
August 4, 2020
The Key to the Rosgen Stream Classification of Natural Rivers:
https://wiIdlandhydrology.com/resources/docs/River%20Restoration%20and%20Natural%20Channel%20
Desian/Rosaen 2011 Natural Channel Desian.Ddf
Wolman Pebble Count:
https://dep.wv.,qov/WWE/getinvolved/sos/Documents/SOPs/PebbleCount Methods.pdf
Bank Erosion Hazard Index:
https://dep.wv.gov/WWE/getinvolved/sos/Documents/SOPs/BEH I -Overview. pdf
North Carolina Stream Assessment Methodology:
https://www.saw.usace.army.miI/Portals/59/docs/regulatorv/publicnotices/2013/NCSAM Draft User Man
ual 130318.pdf
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