20160321 Ver 1_More Info Received_20161121

Fox, Tim
From:
Philip Ellis <[e-mail]>
Sent:
Friday, November 18, 2016 2:24 PM
To:
Fox, Tim
Cc:
[e-mail]; Leslie, Andrea J; Price, Zan (George); Joshua Robinson;
Hutch Kerns; Rebecca Cipriano
Subject:
Re: Highland Biological Station Macon County
Attachments:
00_PCN_HighlandsBiologicalStation.pdf
Tim,
Thank you for talking to me earlier today. Based on our conversation, I have amended some of the submittal
package and the PCN tables (see attached).
Also, answers / commentary to your concerns are in bold below.
Philip Ellis, MS, PE
[phone]
rob i nso ndes i,gn en a ineers. corn
On Nov 18, 2016, at 9:20 AM, Fox, Tim <tim,fox(ttilncdenr. aov> wrote:
Philip,
Let's discuss by phone, I just left you a message and I will try you later this morning. The main items
that I would like further clarification on include:
Once the Lake is drawn down and equipment is mobilized to place fill and install the piers, what erosion
control measures are proposed to reduce turbidity and sediment loss during the duration of the project.
Temporary silt fence will be installed at the toe of all fill, intercepting any potential runoff before coming
into contact with the lake.
Furthermore, the pump / siphon intakes will be at the pond surface during construction—allowing
sediment to drop out of the water column before it is conveyed downstream.
Will timber mats be used to access the impacted area (temporary impacts) or are there any other
proposed temporary impacts proposed during the construction phase?
Yes, we have amended the PCN to account for these impacts.
Will the footings for the piers include any concrete or will they be solely pile driven?

of Art#p Office Use Only:
Corps action ID no.
a DWQ project no.
Form Version 1.4 January 2009
Page 1 of 10
PCN Form—Version 1.4 January 2009
Pre -Construction Notification (PCN) Form
A.
Applicant Information
1.
Processing
la.
Type(s) of approval sought from the Corps:
❑✓ Section 404 Permit ❑ Section 10 Permit
1b.
Specify Nationwide Permit (NWP) number: 3 & 42 or General Permit (GP) number:
1c.
Has the NWP or GP number been verified by the Corps? ❑✓ Yes ❑ No
1d.
Type(s) of approval sought from the DWQ (check all that apply):
0 401 Water Quality Certification — Regular ❑ Non -404 Jurisdictional General Permit
❑ 401 Water Quality Certification — Express ❑ Riparian Buffer Authorization
1 e.
Is this notification solely for the record
because written approval is not required?
For the record only for DWQ
401 Certification:
❑ Yes 0 No
For the record only for Corps Permit:
❑ Yes 0 No
1f.
Is payment into a mitigation bank or in -lieu fee program proposed for
mitigation of impacts? If so, attach the acceptance letter from mitigation bank
or in -lieu fee program.
❑ Yes ❑✓ No
1g.
Is the project located in any of NC's twenty coastal counties. If yes, answer 1h
below.
❑yes ZNo
1h.
Is the project located within a NC DCM Area of Environmental Concern (AEC)?
❑ Yes 0 No
2.
Project Information
2a.
Name of project:
Highlands Biological Station
2b.
County:
Macon
2c.
Nearest municipality/town:
Highlands
2d.
Subdivision name:
NA
2e.
NCDOT only, T.I.P. or state project no:
NA
3.
Owner Information
3a.
Name(s) on Recorded Deed:
Highlands Biological Foundation
31b.
Deed Book and Page No.
book 3, page 134
3c.
Responsible Party (for LLC if
applicable):
Sonya Carpenter
3d.
Street address:
265 North 6th Street
3e.
City, state, zip:
Highlands, NC 28741
3f.
Telephone no.:
[phone]
3g.
Fax no.:
3h.
Email address:
highlandsbiological®gmail.com
Page 1 of 10
PCN Form—Version 1.4 January 2009

ROBINSON DESIGN ENGINEERS'
Land. Water. Ecology.
Date: Friday, November 18, 2016
To: David Brown, PG
Regulatory Specialist / Geologist
US Army Corps of Engineers
828-271-7980, eat. 232
submitted via email <[e-mail]
Asheville, NC 28801
CC: Tim Fox, NCDEQ-DWR <[e-mail]>
Andrea Leslie, NC Wildlife Resource Commision <[e-mail]>
RE:
Highlands Biological Station
Action ID SAW -2016-00486
Delivered via:
email
Contents:
1 PCN (amended)
1 PCN Narrative (amended)
1 Set of site plans (amended)
1 Cold Water Release Narrative
1 Cold Water Release Plan
1 Set of Cold Water Release Details
1 Additional clarification and specifications
1 Recommendations from WRC
REMARKS
Please find the enclosed fourth submittal for the proposed impacts to waters of the United States.
The PCN (page 4, section C.2.) has been amended to incorporate temporary impacts.
The PCN Narrative has been amended to incorporate the temporary impacts and to add
specifications related to handling of concrete.
The site plans have been amended (sheet LP.04) to show the proposed re -alignment of S1, and
location of the temporary timber -mat.
I have also included recommendations from the Wildlife Resources Commission prepared by
Andrea Leslie.
Should you have any questions whatsoever, please contact me directly at [phone].
Thank you,
Philip Ellis, PE
pe@ robinsondesignengineers. com
Robinson Design Engineers
14 Church Street
Asheville, NC 28801

Footings for the outdoor class room will be poured concrete. The footings are included in 03 on the PCN
and will be constructed in the dry.
Since there is a stream running into the Lake and a channel will still be present after drawdown what
steps or plan would be in place if construction equipment will need to cross flowing water to access the
area where the piers are installed.
Timber mats will be utilized to cross Sl and prevent machinery from causing permanent compaction or
or rutting.
There should also be a visual monitoring plan during lake drawdown and the construction activity phase
to ensure minimum flow requirements are being met and turbidity and sediment standards are not
being violated.
The contractor will perform and keep records of daily visual inspections. On a weekly basis, a
representative from the design team will inspect the site and review the daily -inspection log.
Thanks,
Tim
Tim Fox - tim.fox(R)ncdenr.gov
North Carolina Dept. of Environmental Quality
Asheville Regional Office
Division of Water Resources— Water Quality Programs
2090 U.S. 70 Highway
Swannanoa, NC 28778
Tel: [phone]
Fax: [phone]

4.
Applicant Information (if different from owner)
4a.
Applicant is:
❑ Agent ❑ Other, specify:
4b.
Name:
4c.
Business name
(if applicable):
4d.
Street address:
4e.
City, state, zip:
4f.
Telephone no.:
4g.
Fax no.:
41h.
Email address:
5.
Agent/Consultant Information (if applicable)
5a.
Name:
Philip Ellis
51b.
Business name
(if applicable):
Robinson Design Engineers
5c.
Street address:
14 Church Street
5d.
City, state, zip:
Asheville, NC 28801
5e.
Telephone no.:
[phone]
5f.
Fax no.:
5g.
Email address:
peg robinsondesignengineers.com
Page 2 of 10

B.
Project Information and Prior Project History
1.
Property Identification.
la.
Property identification no. (tax PIN or parcel ID):
7540711159
16.
Site coordinates (in decimal degrees):
ILatitude: 35.054939 Longitude: -83.188296
1c.
Properly size:
10.5 acres
2.
Surface Waters
2a.
Name of nearest body of water to proposed project:
Lindenwood Lake (Ravenel Lake)
2b.
Water quality Classification of nearest receiving water:
WS-III;TR
2c.
River basin:
Tennessee (06010202)
3.
Project Description
3a. Describe the existing conditions on the site and the general land use in the vicinity of the project at the time of this
application:
Lake, dam, trails, and associated facilities for recreation and educational uses
3b.
List the total estimated acreage of all existing wetlands on the
property:
3c.
List the total estimated linear feet of all existing streams (intermittent and perennial) on the property:
3d. Explain the purpose of the proposed project:
Dam maintenance and new recreational structures.
3e. Describe the overall project in detail, including the type of equipment to be used:
See attached narrative and exhibits..
4.
Jurisdictional Determinations
4a.
Have jurisdictional wetland or stream determinations by the
Corps or State been requested or obtained for this property/
project(including all priorphases) in the pasd7
❑ Yes 0 No ❑ Unknown
Comments:
4b.
If the Corps
of determination
made the jurisdictional determination, what type
was made?
❑ Preliminary ❑ Final
4c.
If yes, who delineated the jurisdictional areas?
Name (if known):
Agency/Consultant Company:
Other:
4d.
If yes, list the dates of the Corps jurisdictional determinations or State determinations and attach documentation.
5.
Project History -
5a.
Have permits or certifications been requested or obtained for
this project (including all prior phases) in the past?
❑Yes ❑ No 0 Unknown
5b.
NA
If yes, explain in detail according to "help file" instructions.
6.
Future Project Plans
6a.
Is this a phased project?
❑ Yes 0 No
6b.
If yes, explain.
Page 3 of 10
PCN Form—Version 1.4 January 2009

C. Proposed Impacts Inventory
1. Impacts Summary
1a. Which sections were completed below for your project (check all that apply):
❑✓ Wetlands✓❑ Streams — tributaries ❑ Buffers ❑✓ Open Waters ❑ Pond Construction
2. Wetland Impacts
If there are wetland impacts proposed on the site, then complete this question for each wetland area impacted.
2a.
Welland impact
number
Permanent (P) or
Temporary T
2b.
Type of impact -
2c.
Type of wetland
2d.
Forested
2e.
Type of jurisdiction
Corps (404,10) or
DWQ (401, other)
2f.
Area of
impact
(acres)
W1 P
Fill
Mountain Bog
No
Corps
0.0386
W2 T
Fill
Mountain Bog
No
Corps
0.0021
W3
W4
W5
W6
2g. Total Wetland Impacts:
0.0407
2h. Comments:
All fill is associated with Ni and is annotated as wefland fill on sheet LP.o4. W2 is temporary fill for access to the outdoor class room via
temporary timber -mets.
3. Stream Impacts
If there are perennial or intermittent stream impacts (including temporary impacts) proposed on the site, then complete this
question for all stream sites impacted.
3a.
Stream impact
number
Permanent (P) or
Temporary (T)
3b.
Type of impact
3c.
Stream name
3d.
Perennial (PER) or
intermittent (INT)?
-
3e.
Type of
jurisdiction
3f.
Average
stream
width
(feet)
3g.
Impact
length
(linear
feet)
S1 P
Fill
UT1 to Mill Crack
PER
Corps
3
68
S2
S3
S4
S5
S6
3h. Total stream and tributary impacts
3i. Comments:
Annotated as stream fill on sheet LP.09
Page 4 of 10
PCN Form — Version 1.4 January 2009

4. Open Water Impacts
If there are proposed impacts to lakes, ponds, estuaries, tributaries, sounds, the Atlantic Ocean, or any other open water of
the U.S. then individually list all open water impacts below.
4a
Open water
impact number
Permanent (P) or
Temporary T
4b.
Name of waterbody
(if applicable
4c.
Type of impact
4d.
Waterbody
type
4e.
Area of impact (acres)
01 P
Underwood Lake
Fill
Pond
0.1725 acres
O2 P
Underwood Lake
Fill
Pond
0.0009 acres
03 P
Lindanwood Lake
Fill
Pond
0.0006 acres
04 -
Choose one
Choose
4E Total open water impacts
o.nas acres
4g. Comments: volumes: _ co (structuralalong am; = c approximaey riser
NWP#42 Volumes: 01= 9,045 cf of fill (approximately 3 got fill -depth); 03 321 of of fill (13 piers and footings)
5. Pond or Lake Construction
If ontl or lake construction proposed, the complete the chart below.
5a.
Pond ID number
5b.
Proposed use or
purpose of pond
50. 5d 5e.
Wetland Impacts (acres) Stream Impacts (feet) Upland
(acres)
Flooded
Filled
Excavated Flooded
Filled
Excavated
P1
Choose one
P2
5f. Total:
5g. Comments:
5h. Is a dam high hazard permit required?
❑ Yes ❑ No If yes, permit ID no:
5i. Expected pondsudade area (acres):
5j. Size of pond watershed (acres):
5k. Method of construction:
6. Buffer Impacts (for DWq)
If project will impact a protected riparian buffer, then complete the chart below. If yes, then individually list all buffer impacts
below. If any impacts require mitigation, then you MUST fill out Section D of this form.
6a. Project is in which protected basin?
❑ Neuse ❑ Tar -Pamlico ❑ Catawba ❑ Randleman ❑ Other:
66.
Buffer Impact
number—
Permanent (P) or
Temporary T)
6c.
Reason for impact
6d.
Stream name
6e.
Buffer
mitigation
required?
6f.
Zone 1
impact
(square
feet)
6g.
Zone 2
impact
(square
feet
B1
B2
B3
B4
B5
B6
6h. Total Buffer Impacts:
6i. Comments:
Page 5 of 10

D.
Impact Justification and Mitigation
1.
Avoidance and Minimization
1a. Specifically describe measures taken to avoid or minimize the proposed impacts in designing project.
Site has been master -planned to avoid and minimize streams and wetlands.
1b. Specifically describe measures taken to avoid or minimize the proposed impacts through construction techniques.
See attached narrative.
2.
Compensatory Mitigation for Impacts to Waters of the U.S.
or Waters of the State
2a.
Does the project require Compensatory Mitigation for
impacts to Waters of the U.S. or Waters of the State?
❑ Yes ❑✓ No
2b.
If yes, mitigation is required by (check all that apply):
❑ DWQ ❑ Corps
2c.
If yes, which mitigation option will be used for this
project?
❑ Mitigation bank
❑Payment to in -lieu fee program
❑ Permittee Responsible Mitigation
3.
Complete if Using a Mitigation Bank
3a.
Name of Mitigation Bank:
3b.
Credits Purchased (attach receipt and letter)
Type:
Type:
Type:
Quantity:
Quantity:
Quantity:
3c.
Comments:
4.
Complete if Making a Payment to In -lieu Fee Program
4a.
Approval letter from in -lieu fee program is attached.
❑ Yes
4b.
Stream mitigation requested:
linear feet
4c.
If using stream mitigation, stream temperature:
4d.
Buffer mitigation requested (DWQ only):
square feet
4e.
Riparian wetland mitigation requested:
acres
4f.
Non -riparian wetland mitigation requested:
acres
4g.
Coastal (tidal) wetland mitigation requested:
acres
4h.
Comments:
5.
Complete if Using a Permittee Responsible Mitigation Plan
5a.
If using a permittee responsible mitigation plan, provide a description of the proposed mitigation plan.
Page 6 of 10
PCN Form—Version 1.4 January 2009

6. Buffer Mitigation (State Regulated Riparian Buffer Rules) — required by UWQ
6a. Will the project result in an impact within a protected riparian buffer that requires
buffer mitigation?
❑ yes ❑ No
6b. If yes, then identify the square feet of impact to each zone of the riparian buffer that requires mitigation. Calculate the
amount of mitigation required.
Zone
6c.
Reason for impact
6d.
Total impact
(square feet)
Multiplier
6e.
Required mitigation
(square feet)
Zone 1.
3 (2 for Catawba)
Zone 2
1.5
6f. Total buffer mitigation required:
6g. If buffer mitigation is required, discuss what type of mitigation is proposed (e.g., payment to private mitigation bank,
permittee responsible riparian buffer restoration, payment into an approved in -lieu fee fund).
6h. Comments:
Page 7 of 10

E.
Stormwater Management and Diffuse Flow Plan (required by DWQ)
1.
Diffuse Flow Plan
1a.
Does the project include or is it adjacent to protected riparian buffers identified
❑ Yes
0 No
within one of the NC Riparian Buffer Protection Rules9
1 It.
If yes, then is a diffuse flow plan included? If no, explain why.
El Yes
E] No
2.
Stormwater Management Plan
2a.
What is the overall percent imperviousness of this project?
5
21b.
Does this project require a Stormwater Management Plan?
El Yes
J❑ No
2c.
If this project DOES NOT require a Stormwater Management Plan, explain why:
Not large enough to warrant.
2d.
If this project DOES require a Stormwater Management Plan, then provide a brief, narrative description of the plan:
NA
2e.
Who will be responsible for the review of the Stormwater Management Plan?
NA
3.
Certified Local Government Stormwater Review
3a.
In which localgovernment's jurisdiction is thisproject?
Highlands
❑ Phase II
❑ NSW
31b.
Which of the following locally -implemented stormwater management programs
USMP
apply (check all that apply):
Water Supply
Watershed
Other:
3c.
Has the approved Stormwater Management Plan with proof of approval been
[-]Yes
❑ No
attached?
4.
DWQ Stormwater Program Review
❑Coastal counties
❑HQW
4a.
Which of the following state -implemented stormwater management programs apply
(check all that apply):
BORW
Session Law
2006-246
[—]Other:
4b.
Has the approved Stormwater Management Plan with proof of approval been
❑Yes
❑ No
attached?
5.
DW0401 Unit Stormwater Review
5a.
Does the Stormwater Management Plan meet the appropriate requirements?
[]Yes
❑ No
51b.
Have all of the 401 Unit submittal requirements been met?
❑Yes
❑ No
Page 8 of 10
PCN Form — Version 1.4 January 2009

F.
Supplementary Information
1.
Environmental Documentation (DWQ. Requirement)
1a.
Does the project involve an expenditure of public (federal/state/local) funds or the
✓❑Yes ❑ No
use of public (federal/state) land?
1 b.
If you answered "yes" to the above, does the project require preparation of an
environmental document pursuant to the requirements of the National or State
❑Yes ❑✓ No
(North Carolina) Environmental Policy Act (NEPA/SEPA)?
1c.
If you answered "yes' to the above, has the document review beenynalized by the
State Clearing House? (If so, attach a copy of the NEPA or SEPA final approval.
❑Yes F] No
letter.)
Comments:
2.
Violations (DWQ Requirement)
2a.
Is the site in violation of DWQ Wetland Rules (15A NCAC 2H .0500), Isolated
Wetland Rules (15A NCAC 2H .1300), DWQ Surface Water or Wetland Standards,
❑Yes ❑✓ No
or Riparian Buffer Rules (15A NCAC 2B .0200)?
2b.
Is this an after -the -fact permit application?
❑Yes ❑✓ No
2c.
If you answered "yes" to one or both of the above questions, provide an explanation of the violation(s):
3.
Cumulative Impacts (DWQ Requirement)
3a.
Will this project (based on past and reasonably anticipated future impacts) result in
❑Yes ✓❑ No
additional development, which could impact nearby downstream water quality?
3b.
If you answered "yes" to the above, submit a qualitative or quantitative cumulative impact analysis in accordance with the
most recent DWQ policy. If you answered "no," provide a shod narrative description.
4.
Sewage Disposal (DWQ Requirement)
4a.
Clearly detail the ultimate treatment methods and disposition (non -discharge or discharge) of wastewater generated from
the proposed project, or available capacity of the subject facility.
NA
Page 9 of 10
PCN Form —Version 1.4 January 2009

5. Endangered Species and Designated Critical Habitat (Corps Requirement)
5a. Will this project occur in or near an area with federally protected species or
El Yes ZNo
habitat?
51b. Have you checked with the USFWS concerning Endangered Species Act
❑yes ✓❑ No
impacts?
5c. If yes, indicate the USFWS Field Office you have contacted.
5d. What data sources did you use to determine whether your site would impact Endangered Species or Designated Critical
Habitat?
UFWS Critical Habitat Mapper
6. Essential Fish Habitat (Corps Requirement)
6a. Will this project occur in or near an area designated as essential fish habitat?
❑ Yes ❑✓ No
6h. What data sources did you use to determine whether your site would impact Essential Fish Habitat?
NOAA EFH Mapper
7. Historic or Prehistoric Cultural Resources (Corps Requirement)
7a. Will this project occur in or near an area that the state, federal or tribal
governments have designated as having historic or cultural preservation
❑✓ Yes ❑ No
status (e.g., National Historic Trust designation or properties significant in
North Carolina history and archaeology)?
7b. What data sources did you use to determine whether your site would impact historic or archeological resources?
Latest Corps database: Baldwin-Coker Cottage (site ID MA050B) adjoins the de perlyto the north & portions of the Playmore-Bowery Road Historic
District (site ID MA05ag) adjoins the property to the east.
8. Flood Zone Designation (Corps Requirement)
Be. Will this project occur in a FEMA-designated 100-year floodplain?
❑ Yes ✓❑ No
81b. If yes, explain haw project meets FEMA requirements:
Be. What source(s) did you use to make the floodplain determination?
FEMA FIRM
Philip A. EllisC�I,1,1�L/\)
0 (�I//1 IAI
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9/15/2016
Applicant/Agent's Printed Name
Date
Applicant/Agent's Signature
(Agent's signature is valid only if an authorization
letter from the applicant is rovided.
Page 10 of 10

CONCEPTUAL NARRATIVE TO ACCOMPANY THE PRE -CONSTRUCTION NOTIFICATION FORM:
DAM AND SITE IMPROVEMENTS AT THE HIGHLANDS BIOLOGICAL STATION
Prepared for
Highlands Biological Foundation
Highlands, NC
Prepared by
Robinson Design Engineers
Asheville, NC
November. 18, 2916
ROBINSON DESIGN ENGINEERSs'
Land. Water. Ecology.

Highlands Siologlaal SlatiOn/ September 15, 2016
CONCEPTUAL NARRATIVE TO ACCOMPANY THE PRE -CONSTRUCTION NOTIFICATION FORM:
DAM AND SITE IMPROVEMENTS AT THE HIGHLANDS BIOLOGICAL STATION
Preparer.
Philip A. Ellis, Jr., MS, PE
Page 2

Highlands Biological station I September 15, 2016
U11 011111411113-0111-*1U]P
The Highlands Biological Foundation, a non-profit organization that supports the education and research mission of the
Highlands Biological Station, is proposing improvements to their site. Improvements include anew, native pollinator garden,
upgrades to the northeast entrance to the Station campus, and construction of a new outdoor classroom. The pollinator
garden and outdoor classroom will further the mission of the Station and the Foundation, and complement an existing
botanical garden and other displays of local native ecology. The pollinator garden is intended to attract and support the
ecological needs of targeted pollinators in a setting that will be enjoyed by a variety of visitors to the Station. The design of
the proposed garden will encompass the northeast entrance to the Highlands Biological Station, and include shoreline and
dam stabilization measures associated with the outdoor classroom. In addition to plantings designed to attract targeted
pollinator species, the garden and outdoor classroom will feature educational elements, signage, and increased connectivity
to existing botanical trails.
This narrative explains some of the conceptual design efforts a team of consultants has undergone for the planned
improvements at the Highlands Biological Station in Highlands, NC. Information contained herein is based on publicly -
available data, our visits to the site, our data collection, and the conceptual site plan prepared by Kerns Land Planning and
Design.
2. CONCEPTUAL DESIGN
This section will describe the proposed site improvements, their impacts to waters of the United States, and and how they
relate to the values provided on the Pre -Construction Notification Form (PCN).
2.1 Dam Reinforcement
With the planned gardens and improvements to the northeast campus entrance, the Foundation is expecting
increased pedestrian use along the dam and associated trails. With construction activities planned in the
area, and the expected increase in use, the Foundation is proposing to reinforce the upstream side of the
dam with structural fill. The total area of fill is identified as "OT' on the attached exhibits and measures. This
fill is being requested under NWP#3.
2.2 Cold Water Siphon
A small riser will be installed in open water near the dam. This riser will allow the dam owners to have some
control over lake levels, but its primary purpose will be as a cold water siphon. This device will take the
existing primary spillway (top -water withdrawal) off-line and begin drawing water from the bottom 1/3 of the
pond. This device will decrease water temperature for downstream waterbodies, thereby uplifting
downstream riverine habitat. The total area of fill is identified as "02" on the attached exhibits and measures
16 sf or 0.0004 acres. This fill is being requested under NWP#3.
2.3 Outdoor Classroom
An outdoor, lakeside classroom has been envisioned by the Foundation. The proposed layout incorporates
existing and proposed nature trails and gardens, includes plans for native plantings, and minimizes impacts to
existing waters. The total area of fill is identified as "01" and "Al""(temporary) and "W2" and "S1" on the
attached exhibits.
Additionally, piers have been proposed by the structural engineer. The outdoor classroom is to be positioned
over -top of the pond and will require thirteen -2 If diameter piers with 3'1 footings. The total area of fill is
identified as "03" on the attached exhibits and totals to 27 sf or 0.00062 acres. All of this fill associated with
the outdoor classroom is being requested under NWP#42.
Page 3

Highlands Biological Station I September 15.201E
2.4 Quantifying Fill Volumes
In the "Proposed Impacts Inventory' section of the PCN, we have quantified the type and quantity of impact.
These impacts are separated into two different categories, fill associated with NWP#3 and for Ni
u NWP#3: 60% of 01 = 4,500 sf —13,500 of of fill associated with structural fill to reinforce the dam;
NWP#3: 02= 1 B of offill associated with the the cold water siphon, Oft depth;
o NWP#4240%of O1=3,015 sf-9,045 cf of fill for an average depth of 3 ft;
o NWP#42: 03 = 321 of of fill for a total of 13 piers and footings.
3. AVOIDANCE AND MINIMIZATION
Reducing and preventing impacts to any waterbodies is a key component to the design and layout of these
improvements. This section will list all techniques & practices that have been, or are planned to avoid and minimize
impacts from construction of the project. Some of these measures were taken during planning, and some will be imposed
during the the construction process.
3.1 Preventing direct water contamination
Refueling construction equipment will occur at least 200 feet from all water bodies.
n Storing hazardous materials, fuel, lubricating oils, or other chemicals will be done at least 200 feet from all
water bodies, at an upland site.
o Equipment will be inspected and maintained daily to prevent the contamination of surface waters from
leaking fuels, lubricants, hydraulic fluids, or other toxic materials.
u At all practical instances, the contractor will keep equipment out of the pond by operating from the banks in
a fashion that minimizes disturbance to woody vegetation.
o The equipment will be cleaned and checked for leaks of hydraulic fluids, cooling system liquids, and fuel
before entering or crossing a waterbody.
o Wet concrete will not contact the pond, and no fertilizers or pesticides will be used near awaterbody.
o All concrete work shall be done in the dry. Furthermore, at the end of each work -day, all concrete materials
shall be removed from the work area.
3.2 Protecting the lakeside boundary
c Activities will be limited along the lakeside boundary to those absolutely necessary for construction.
c The contractor will maintain riparian vegetation to the maximum extent possible, especially large trees.
a If riparian areas are disturbed, they will be revegetated with native species as soon as possible.
o Areas for stock -piling and construction staging will be located away from in the uplands.
o The proposed site layout will direct inflow away from the dam to reduce maintenance concerns and and
3.3 Preventing or minimizing erosion
In order to minimize the amount of soil that enters a stream during the construction of a project, the
construction drawings will be specifying the following:
a Installation of erosion control measures prior to ground disturbing activities, and frequent maintenance of
these measures throughout the construction process.
o Planting all disturbed areas with native grasses and tree species.
o Planting temporary (e.g., rye, grain, wheat, millet) or permanent herbaceous material to help control
erosion immediately following any ground disturbing activity (native annual small grains and herbs
appropriate for the season are recommended).
Page 4

Highlands Biological Station f September 15. 2016
3.4 Stormwater management
Most development creates impervious surfaces (such as roofs, roads, and parking lots), which collect
pathogens, metals, sediment, and chemical pollutants and and quickly transmits them to streams, lakes and
wetlands. In order to address these secondary impacts of the project, the conceptual site layout took the
fallowing approach.
u The amount of impervious surface is minimized. The proposed trails and any additional parking areas will
not be paved. Any proposed decking or boardwalks will be constructed with boards and slats so that
rainfall runoff will not travel in the horizontal direction.
o The use of low -impact -development (LID) techniques have been used while planning the site.
3.5 Protecting migratory birds
The Migratory Bird Treaty Act (16 U.S.C. 703-712) prohibits the taking, killing, possession, transportation, and
importation of migratory birds (including the bald eagle), their eggs, parts, and nests, except when specifically
authorized by the Department of the Interior. To avoid impacts to migratory birds, the design team will be
recommending the fallowing'.
o Conducting a visual inspection of the pond and construction area for migratory bird nesting habitat within
the project area during the migratory bird nesting season of March through September. If migratory birds
are discovered nesting in the project impact area, including on the existing shoreline, impacting the nests
should be avoided during the migratory bird nesting season (March through September).,
o If birds are discovered nesting on shoreline during years prior to the proposed construction date, measures
should be developed to discourage birds from establishing nests by means that will not result in the take of
the birds or eggs, or construction and demolition activities should be avoided during the nesting period.
Page 5

EXHIBITS
The following items are attached as addendum:
• LP.01 — Overall Aerial Plan
• LP.02— Overall Conceptual Plan
• LP.03— Overall Site Plan
• LP.04— Site Enlargement
• LP.05— Site Enlargement
• Cold Water Release Narrative
• Cold Water Release Plan
• Cold Water Release Details (NRCS)
Highlands Slolegieel Starlon /September 15, 2016
Page 6

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CONCEPTUAL NARRATIVE TO ACCOMPANY COLO WATER SIPHON SCHEMATICS
Prepared for
Highlands Biological Foundation
Highlands, NO
Prepared by
Robinson Design Engineers
Asheville, NO
September 19, 2016
ROBINSON DESIGN ENGINEERSs"
Lmd.Water.Ecology.

Hlghlantls biological stertor f September 10, 2016
1. INTRODUCTION
The Highlands Biological Foundation, a non-profit organization that supports the education and research mission of the
Highlands Biological Station, is proposing improvements to their site. Improvements include a native pollinator garden,
upgrades to the northeast entrance, construction of an outdoor classroom, and the addition of a cold water release structure
as the primary spillway for Lindenwood Lake.
This narrative explains the need for a cold water release structure, the functionality of a siphon spillway, and will outline the
conceptual design efforts for the planned release structure. Information contained herein is based on publicly -available data,
our visits to the site, our data collection, and the conceptual site plan prepared by Kerns Land Planning and Design.
2. TEMPERATURE STANDARDS
The North Carolina Department of Environmental Quality (NCDEQ) Division of Water Resources (DWR) enforces
temperature standards throughout the state. NC Administrative Code section 02B .0211 'FRESH SURFACE WATER
QUALITY STANDARDS FOR CLASS C WATERS" states that the temperature for trout waters shall not be increased by
more than 0.9 degrees F due to the discharge of heated liquids, but in no case to exceed 68 degrees F.
NCDEQ is not enforcing these standards with a quantitative measurements; instead, DWR is requesting that all work
performed in or adjacent to existing reservoirs include a cold water release structure as part of the development plan. The
cold water intake position needs to be deep enough to reach the cooler waters of the pond that have not be overly heated by
solar radiation, The intake elevation should be in the bottom third of the reservoir and should leave at least two feet of
clearance above the bottom to avoid interference from sediment accumulation.
3. COLD WATER RELEASE STRUCTURES
Coldwater release structures are installed to reduce the thermal Impacts of pond outflows. When installing a cold water '-
release structure, there are generally two options: install a subsurface intake stand pipe, or a siphon spillway. These options, -
and their applicability to Lindenwood Lake are discussed below.
3.1 STAND PIPE RETRO -FIT
This option is best suited when there is an existing stand pipe. Typically in this situation, there would be an
existing primary spillway that enters the system through a vertical stand pipe. After entering the standpipe
water flows via gravity inside conduit directly through the core of the dam. In order to retro -fit such a system,
a sheath would be fabricated and affixed to the existing stand pipe that forced water to enter the system at a
specified depth.
Since Lindenwood Lake does not have an existing stand pipe, and creating one would require breaching the
the dam, this is not a preferred option.
3.2 SIPHON RETRO -FIT
A siphon is the preferred option at Lindenwood Lake.
A siphon spillway is a closed conduit system formed in the shape of an inverted "U", positioned so that the
invert of the bend (at the crest) of the upper passageway is at normal water surface elevation. Siphons can
lift water over obstructions at a higher level than the source; this principle advantage provides an opportunity
to create a spillway without the requirement to breach the dam. The initial discharge of the siphon, as the
Page 2

Highlands Blologlael Station I September 19, 2016
reservoir level rises above normal, is similar to flow over a weir. Siphoning action begins after the air in the
siphon pipe has been exhausted; usually at a depth over the crest equal to about 1/3 the pipe diameter. An
air vent is provided to break the siphoning action when the reservoir water surface is drawn down to normal
pool elevation. Because of the negative pressure that exists within the siphon when flowing full, air tight pipe
joints and pipe sufficiently rigid to withstand the collapsing forces is required. Welded steel or plastic pipe
with glued joints is preferred over using rubber gasketed joints.
Based on the state -of -practice for installation of siphons, we advise the following minimum criteria in the
design of siphon spillway systems:
• Limit the total drop of the siphon to a maximum of 20 feet.
in Use a 2 -in. diameter vent pipe on siphon pipes less than 8 -in. and a 4 -in. diameter vent pipe for all
other siphons.
• Use smooth steel or smooth plastic pipe with a minimum wall thickness equivalent to Schedule 40 or
SDR 26 for siphon systems.
in Install an elbow on the downstream end of the siphon to encourage energy disipation.
in Bury the pipe through the dam and bury the downstream section of the pipe or install adequate
anchors and restraints to prevent thrust forces and vibrations from breaking the pipe.
• Protect the vent pipe using a perforated pipe sleeve to prevent floating debris from clogging the vent.
Install perforations in the vent pipe sleeve with a total area equal to at least two times the vent pipe
area.
• Install a perforated inlet section on the siphon with open area equivalent to at least two times the crass
sectional area of the siphon pipe to exclude trash, turtles, fish, etc.
• Protect the end of the pipe from clogging by using an end cap or screen.
In addition to these minimum criteria, we suggest following the design procedures outlined in FEMA Technical
Manuals #484 and #675 "Conduits through Embankment Dams" and "Plastic Pipe Used in Embankment
Dams," respectively.
4. SIPHON DESIGN COMPONENTS
What follows is a brief description of the principles and functionality to consider before constructing a siphon spillway.
4.1 MODES OF OPERATION
There are four stages to siphon flow and each of these stages has a unique relationship between air
entrapment, entrainment, and full pipe flow:
1) Non -pressurized weir flow — this will be the year-round base -line flow.
2) Sub -atmospheric weir flow, and 3) partial flow — air entrapment exists throughout the weir section and
intermittently throughout the section of pipe along the back of the dam. Air entrapment describes when a
bubble of air is taking up space in pipe. This prevents the system from reaching full pipe flow and reduces
momentum for the system. Air entrainment describes air that is moving through the system and becoming
pad of the discharge. A result of this physical phenomena in siphon systems is a "whitewater" visual effect at
the outlet. This is a reduced discharge rate from the full pipe flow.
Lastly, 4) Pressurized flow — full pipe flow is exhibited as fluid flowing through the entire cross sectional area
of the pipe.
When the lake water level is discharged below the elevation of the vent, the siphon operating stages should
go from full pipe flow to air entrainment to air entrapment and finally back to non -pressurized weir flow.
4.2 HORIZONTAL LOCATION
Horizontal location of the intake orifice can be any location near the deep areas of the lake. In an effort to
reduce the cost of materials and labor for the construction of the siphon, we recommend locating the intake
Page 3

Highlands Biological Sound l September 14 2016
device as close as practicable to the existing spillway. The spillway conduit can be partially buried and
Horizontal location of the outflow orifice should be competently placed so that flows enter the existing stream -
bed without causing excess erasion.
4.3 VERTICAL LOCATION
Siphons are limited to lifts of about 15ft. Common failure mechanisms arise due to the low pressure at the
uppermost point, which can allow air to come out of the solution, which initially causes an obstruction and
reduces the flaw of water, and which can grow sufficiently to form an airlock which stops the flow. Therefore,
the siphon pipe, which is entirely at a sub atmospheric pressure, must be completely air -tight. Also, in
general, the faster the flow, the lower the lift; and the more perfect the joints, the less trouble there is likely to
be with air locks. Starting siphons off can also present problems. The simplest siphons can be short lengths of
flexible plastic hose which may typically be used to irrigate a plot by carrying water from a conveyance
channel over a low bund; it is well known that all that needs to be done is to fill the length of hose completely
by submerging it in the channel and then one end can be covered by hand usually and lifted over the bund, to
allow siphoning to start. Obviously, with bigger siphons, which are often needed when there is an obstruction
which cannot easily be bored through or removed, or where there is a risk of leakage from a dam or earth
bund if a pipe is buried in it, simple techniques like this cannot be used.
4.4 DESIGN FLOWS
The drainage area for Lindenwood Lake is approximately 200 acres (0.3 sq miles). This is a relatively small
drainage area, but considering its landscape position and the extremely high rainfall patterns in the Highlands,
NC region, the oufflow from Lindenwood Lake will be prone to relatively high flaws. This exercise is not
necessarily used to size the hydraulic structures. Instead we want to have an understanding of the system
and it's "flashiness" to know haw often the proposed siphon will be overwhelmed with incoming storm flow.
The siphon spillway will be a low -flow device, and the existing overflow spillway will still be in operation,
therefore we can assume that higher flows will safely bypass the new siphon system.
For this preliminary exercise we considered a storm that has a 99% yearly recurrence probability. This storm
is relatively small for sizing hydraulic conveyance devices, but we want to reiterate —the proposed siphon
should not be expected to convey all of the storm flows. A storm with this recurrence probability is an event
where the cumulative precipitation is 4.5 inches over 24 hours. If antecedent conditions are dry, this event'
should produce stormflows at the outlet of Lindenwood Lake of approximately 60 cubic feet per second, Data
used to compute this design flows can be found in the appendix of this report.
4.5 DRAW DOWN POTENTIAL
It would be advantageous for the Highlands Biological Foundation to be able to draw down the water level of
Lindenwood Lake for various maintenance purposes such as dredging or dam repairs. This potential to draw
down the lake and consideration of the time required to perform such as procedure, should be considered by
the Highlands Biological Foundation before the construction drawings are completed.
4.6 SEASONAL WATER LEVEL MANAGEMENT
Seasonal water level management can be designed into the functionality of the proposed siphon. This would
be accomplished by constructing two separate "weir pipes" that can be taken on and off-line via valves. This
would allow the foundation to introduce a seasonal literal shelf around the perimeter of the Lake.
4.7 MAINTENANCE
Upon construction of the siphon spillway, the Foundation should engage a contract for annual inspections.
This could be incorporated into a larger scope that looks at the entirety of the dam for stability and safety
concerns.
4.8 OUTLET PROTECTION
Bracing, soil, and aggregate conditions should be considered when placing and specifying the outlet for the
siphon.
Page 4

Highlands Blological Soren /September 19. 2016
4.9 CONDUIT MATERIALS
Internal vacuum loads should be considered for siphons or when the internal hydraulic behavior of the system
may allow an internal vacuum to develop. Internal vacuum pressure and pressure on the pipe from a wheel
load seldom occur at the same time; however, site programming should betaken into account and considered
in the computation of percent deflection.
Pages

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COID WATERSIPHON SCHEMATICS
DE910N ENDINEEg3'
HigM1lantls, Macon Co, NC

EmergencySplllway Ft. TW
Crest Elev, r—Eley.
�B' Elev. —� C' Elev
Normal
,not --- •B•-------��1 --
levutlon •A• Row— \ \
�E� \ Total drop In
Tle Down Straps / / L3 \ \ \ siphon = 20 ft.
Inlet Elev, / 'D' elev, _.
2't — — — — — Ezlstlog ground Iln —
'A' Perforated Inlet •F' Elev
pipe with r Holes.
Treated timber bent
support or other
pipe support. See Outlet protect
CENTERLINE PROFILE attached details where required,
Splllway Bottom width Ft
'A' - vent pipe at 0,1 ft, below elev, 'B'.
'B' - Set 'Be at normal pool elevation
'C' - Should be at least M ft. lower than 'B'.
'D' - Elevatlon must be at least 0.1 ft, above 'F'.
'E' - Plpe with holes for trash guard.
Siphon pipe diameter_ Inches �
Vent pipe diameter_ Inches ^�
L = Ll + L2 + L3 + Ly + L5 =_ Ft (Design length).
Design siphon pipe capacity _ cfs, for H = ft
Design emergency spillway capacity cfs
(Survey Notes, Computations, and Design Data Attached)

3/16" or 1/4" rods bent on
end.or with nuts and washers
for securing in pipe. Rods.
nuts and washers shall be brass
1" die. hales or stainless steel.
Nonperforated Rigid PVC
seatmnpiPe
2t Coupling
Ground line J DETAIL "A"
Set end of vent pipe
approximately 0.1 below
water surface.
Perforated trash guard sleeve
for vent pipe. Extend at least
2' below water surface.
—V—
Cap and of
trach guard sleeve �
2" max. spacig between rode.
Rods shall be evenly paced.
sme
No. of ods v with pipe dia.
Drill holes about l" from and
of PVC pipe only large enough SECTION B—B
for the rods used.
(Trash Guard)
and of tee
removable plug.
Secure vent pipe with e
post r other support to
prevent vibration from
breaking vent pipe.
DETAIL "B"
Number of holes and length for siphon inlet.
PIPE DIA. HOLES LENGTH (ft.)
4" 33 1.5
6" 73 2.0
B" 128 2.5
10" 201 3.0
12" 2B9 3.5
4" 363 4.0
6" 480 4.5
NOTE: Table is based on 1" diameter holes spaced
at 2" on center and will provide a total opening
at least 2 times the pipe cross sectional area.

-Ground
surface
A
Note: other outlet evpporte may be more an
maro ed
by me engineer. 4X4
post
Treated 2X4
Scour protection
15
Siphon pipe
Treated 2X8 shaped
TI to fit bottom of pipe.
/
layers roofing
Ground surface
I
felt mastic or other
Pressure treated 4X4 or larger
compressible material
poet. Treatment to be min. of
between pipe and
I
0.4 PCF of CCA.
support.
Concrete backfill
AJ`
Unformed concrete backfill.
TIMBER BENT DETAIL FOR SIPHON OUTLET
Use for above ground pipe, of 4' through ID' dlamelem
outlet pipe
concrete
thrust block m
3
�2 J
SECTION THROUGH THRUST BLOCK
AT OUTLET END OF PVC PIPE
Riprop outlet
protection
Note: A Tbruet block nill be required for
pipe .—.me of 12" or greets. For
emellor pip. diemeten, a treated timber bent
may be need .
SECTION A—A
Neta: Dated. Mi. ,beet me not t. ,cel.

ROBINSON DESIGN ENGINEERS'
Land.Water. Ecology.
November 15, 2016
David Brown
USACE Wilmington District — Asheville Regulatory Field Office
151 Patton Avenue, Room 208, Asheville, NC 28801-5006
[phone], ext. 232
CD
Tim Fox
NCDEQ — Asheville Regional Office
Division of Water Resources— Water Quality Programs
2090 U.S. 70 Highway, Swannanca, NC 28778
[phone]
Andrea Leslie
NC Wildlife Resources Commission— Mountain Habitat Conservation Coordinator
20630 Great Smoky Mountain Expressway, Waynesville, INC 28786
[phone]
Reference: Highlands Biological Station
Town of Highlands, Macon County, NC
Mr. Brown,
Thank you for receiving and carefully considering this technical memorandum. This memo will augment the Pre -
Construction Notification for the above referenced. site. This memo was formulated based on correspondence with
Tim Fox and Andrea Leslie; specifically, this document includes construction specifications and additional figures to
ensure that the project is constructed in accordance with NC Water Quality Certification No. 3890.
If you have any questions or concerns about the information provided heroin, please feel free to contact me directly.
Sincerely,
ROBINSON DESIGN ENGINEERS
Philip Ellis, MS, PE
14 Church Street
Asheville, NC 28801
[phone]
peg robinsondesignengineers.com
www.mbineondesignengmevm.00m

Highlands emm9lcm Station I November 15, 2013 r Paye z of 4
The following justification rational are requested by the Section 401 water quality codification reviewers. Clarification
is in italics.
Clarify the need for placement of rip -rap outlet protection:
Energy dissipation measures are specified to prevent scour and subsequent pollution to downstream
waterbodhes. An energy dissipater is any device designed to protect downstream areas from erosion by
reducing the velocity of flaw to acceptable limits. Further, an energy dissipater will ensure the durability and
longevity of the outlet. The energy dissipater specified at the outtall of the cold water release siphon shall be
sized and placed in accordance with NCDOT standards, and will be located outside of the ordinary high
water mark (Ofii For the purposes of Section 404 of the Clean Water Act, the OHWM defines the
lateral limits of federal jurisdiction over non -tidal water bodies in the absence of adjacent wetlands. The
OHWM is used by the United States Army Corps of Engineers, NCOEO, and the NO Wildlife Resources
Commission to determine the geographical extent of their regulaloryprograms. The OHWM is defined es
the line on the shore established by the fluctuations of water and indicated byphysical characteristics such
as a clear, natural lineimpressed on the bank, shelving, changes in the character of soil, destruction of
terrestrial vegetation, the presence of litter and debris, or other appropriate means that consider the
characteristics o/the surrounding areas.
Clarify the need for impacts to S1 swivel
The need for impacts to Sl and WI are necessary for access to the proposed outdoor classroom. The
classroom has been programmed for full accessibility, with the polev rypoints of ingress and egress via
boardwalk across the proposed re -alignment of Sl. The location of fill mustbe adjacent and contiguous to
the dam and perimeter lake road.
Additionally, the proposed structural -fill in this location will fortfly the dam's resilience, decreasing the risk of
dam failure and subsequent emoronmenfal effects from flooding and sediment impacts. The area of
proposed shuctural-fill will be atop a critical tie-in area. The tie-in area is a critical location for an earthen
dam; this area is critical because of soil and seepage interactions between the native, valley -wall material,
and the imported dam -fill -materiel. This the -in -location lends itself to seepage pathways that have the
potential for piping and ultimate failure of this critical piece of infrastructure. Typical rule -of -thumb
management procedures for these critical tie-in areas are: removing any woody, deep-rooted vegetation;
diverting overland flow; and inspection for any erosion, seepage, boils, or other unstable geotechnhcal
phenomena. The proposed structural fill for this area has been planned in accordance with these
management procedures.
3. Provide s more clear depiction of the current position of stream S1 (all the way to its confluence with open
water):
See the ammended site enlargarent sheet LP.04 attached as an appendix. This figure shows the proposed
re alignment of Sl.

Highlands Biological Station / November 15, 20161 Paye 3 of 4
The following additions are requested by the Section 401 water quality certification reviewers:
1. describe the drawdown methodology to dewater the construction draw;
2. dictate a minimum downstream flow during re -filling of the impoundment;
3. description of the siphon curtail that clearly indicates placement outside of the 0HWM;
4. identification of posbconstruction alignment of 81;
5. Identification of any temporary impacts to surrounding wetlands an a result of construction traffic and /or
dewatering effects;
6. describe how the construction footprint (disturbed area) is being minimized.
In order to ensure the above mentioned requirements are met, the construction documents will include the following
specifications:
Re -Alignment of Sl
The existing alignment of S1 is in a constant state of fluctuation because of the nature of a natural stream
flowing into an impoundment. This phenomena has created an alluvial fan (or delta), which is continually
building up the wetland area identified as Wt. The existing, primary flow path of S1 is adjacent to the
pond's edge and terminates at the earthen dam. Because of the sediment transport phenomena present in
this alluvial fan, there are multiple low-lying channel features withing the lake and wetland area that become
activated during storm events. These law -lying channel features will not be disturbed. The proposed
changes in plan -form geometry to S1 will likely cause the low-lying channels to be activated with flowing
water on a more frequent recurrence interval.
Drawdown Methodology
The initial drawdown of lake pool elevation will be accomplished via pumps. The lake pool elevation shall be
drawn down so that the entire work area is "in -the -dry." During construction activities, all disturbed area
shall be protected from runoff into Waters of the US. Once the siphon is in place, future drawdown
exercises can be accomplished without the use of pumps.
Minimum Flow Requirements
Downstream flows from the lake must be maintained at all times. During re -tilling of the lake, measures must
be taken to ensure that minimum flow requirements to downstream water bodies are met. To accomplish
these downstream flow requirements, the contractor shall prepare a simple, plastic pipe siphon with a
diameter of approximately 1 inch (or equivalent approved by the engineer). In order for the siphon to
function properly and maintain a minimum flow greater than 40 gallons per minute, the driving -head shall be
a minimum of 10 feet. Driving -head is defined by the difference in elevation between the water surface of
the lake and the point of discharge from the siphon.
Wetland Impact Minimization
The disturbance and / or encroachment to Waters of the US has been minimized to the maximum extent
possible. The contractor shall not disturb any area outside the limits of disturbance. Disturbance includes
all machinery and foot traffic. All staging, lay -down, and stock pile areas shall be located outside of Waters
of the US (streams, wetlands, and open water); additionally all such areas will be constructed in accordance
with NCDEO Erosion and Sediment Control Planning and Design Manual

Highlands Biological Station I November 15. 20161 Page 4 oto
Energy Dissipater
The energy dissipater specified at the outfall of the cold water release siphon shall be sized and placed in
accordance with NCDOT standards, and will be located outs ide of the ordinary high water mark (OHWM).
The CHASM is defined as the line on the shore established by the fluctuations of water and indicated by
physical characteristics such as a clear, natural line impressed on the bank, shelving, changes in the
character of soil, destruction of terrestrial vegetation, the presence of litter and debris, or other appropriate
means that consider the characteristics of the surrounding areas. For the purposes of Section 404 of the
Clean Water Act, the OHWM defines the lateral limits of federal jurisdiction over non -tidal water ending in
the absence of adjacent wetlands. The OHM is used by the United States Army Carps of Engineers,
NCDEQ, and the NC Wildlife He sources Commission to determine the geographical extent of their
regulatory programs.

KJ North Carolina Wildlife Resources Commission
Gordon Myers, Executive Director
November 18, 2016
Mr. David Brown
U.S. Army Corps of Engineers, Regulatory Branch
151 Patton Avenue, Room 208
Asheville, North Carolina 28801-5006
SUBJECT: Highlands Biological Station
UT to Mill Creek, Macon County
Dear Mr. Brown: -
Biologists with the North Carolina Wildlife Resources Commission(NCWRC) reviewed an application to
impact 0.04 acres of wetland and 69 feet of an unnamed tributary (UT) to Mill Creek associated with
Ravenel Lake in Highlands, Macon County. I visited the site with the project designer and Highlands
Biological Station in April of this year. Our comments on this application are offered for your
consideration under provisions of the Clean Water Act of 1977 (33 U.S.C. 466 at. seq.) and Fish and
Wildlife Coordination Act (48 Stat. 401, as amended; 16 U.S.C. 661-667d).
The project should not impact wild trout, and project activities do not need to be avoided during the trout
moratorium. Ravenel Lake has a wetland fringe of varied width around its. perimeter; the wetland has
many characteristics of a Southern Appalachian Bog, including numerous bog plant species resulting from
intentional planting and natural recruitment. The lake impounds several streams that are UTs to Mill
Creek.
The project proposes to build an outdoor classroom, resulting in 0.04 acres of wetland fill and 69 feet of
impact to a UT to Mill Creek. The lower end of the stream channel will be filled and the stream
redirected to the open water of the lake in another location. The classroom will be built on pilings placed
in the open water portion of the lake. The dam will be reinforced and a coldwater siphon installed in
order to transform the lake release from a topwater spillway to a siphon that will pull water from the
lower 1/3 of the lake.
It is unclear if there will be temporary impacts to wetlands during construction associated with equipment
mobilization; these impacts should be minimized by keeping the footprint small and using mats to
minimize soil disturbance. Details we not provided for the methods that will be used to control sediment
loss from the construction site; it is important to retain sediment on site.
In order to construct the outdoor classroom in the dry, lake levels will be lowered with pumps until the
coldwater siphon is in place, after which lake levels will be adjusted with the siphon. Downstream flows
Mailing Address: Habitat Conservation • 1721 Mail Service Center • Raleigh, NC 27699-1721
Telephone: [phone] • Fax: [phone]

Highlands Biological Station Page 2 November 18, 2016
UT Mill Creek, Macon County
will be maintained, and during lake refill, a proposed flow of greater than 40 gal/min (or 0.09 cfs) will be
maintained. We recommend that minimum flows during refill be either 50% of incoming flows or the
3002 value. Using the flow statistics for the Mill Creek site in Giese and Mason (1993) as a reference,
we estimated flow statistics for Lake Ravenel by applying a ratio of the Ravenel Lake drainage area (0.3
mit) to that of the Mill Creek gauged site (1.15 mi'). This results in an estimated 7Q10 of 0.08 cfs, a
30Q2 of 0.23 cis, and a mean annual flow of 1.05 cfs.
We appreciate the Highland Biological Station's efforts to improve outflows from Ravenel Lake by
installing a coldwater siphon. We are supportive of the objective to create an outdoor classroom, as well.
We offer the following recommendations to minimize impacts to fish and wildlife resources:
1. Work should be accomplished as quickly as possible and vigilance used in sediment and erosion
control during site preparation, construction, and clean up. Disturbed areas should be seeded,
mulched and matted as soon as possible. Sediment and erosion controls should be installed to retain
sediment in the work area and out of the lake.
2. Lake drawdown should be accomplished with pumps set at the surface of the lake in order to
minimize sediment release downstream. Once the coldwater siphon is on line, it is important to
monitor the turbidity of the outflows; if outflows arc turbid due to sediment loss from construction
activities, then activities should cease. If surface pumps can maintain appropriate lake levels and
reduce turbidity in outflows, then they should be used instead.
3. Any erosion control matting used be free of plastic or nylon mesh, as this type of mesh netting
frequently entangles wildlife and is slow to degrade, resulting in a hazard that may last for years.
4. Downstream flows should be maintained at all times, and during lake refill a minimum of 50% of the
incoming flows or the 30Q2 flow of 0.23 cfs maintained.
5. Temporary impacts to wetlands should be minimized. Any areas impacted should be replanted with
native species.
6. Wetland areas to be permanently and temporarily impacted should be surveyed for rare plants and
these plants transplanted to other areas of the wetland before impacts.
Thank you for the opportunity to review and comment on this project. Please contact me at (828) 558-
6011 if you have any questions about these comments.
Sincerely,
Andrea Leslie
Mountain Region Coordinator, Habitat Conservation Program
ec: Philip Ellis, Robinson Design Engineers -
Jim Costa, Highlands Biological. Station
Tim Fox, NC Division of Water Resources
Byron Hamstead, US Fish and Wildlife Service