HomeMy WebLinkAbout20201735 Ver 1_WRC Comments_20210203Strickland, Bev
From: Dunn, Maria T.
Sent: Wednesday, February 3, 2021 1:42 PM
To: Mairs, Robb L
Subject: FW: [External] City of Boiling Spring Lakes Dams Construction/Reconstruction Project
- Requested Information
Attachments: BSL - NCWRC Request for Information 020321.pdf
Hi Robb. I'm not sure who in DWR is reviewing this or if there is interest. Chad was involved back in the day and was on
this email but I thought I should forward along anyway.
Maria T. Dunn
Coastal Coordinator
NC Wildlife Resources Commission
943 Washington Sq. Mall
Washington, NC 27889
office: 252-948-3916
www.ncwiIdlife.org
Email correspondence to and from this sender is subject to the N.C. Public Records Law and may be disclosed to third parties.
From: Jon Swaim <jon.swaim@mcgillassociates.com>
Sent: Wednesday, February 3, 2021 12:06 PM
To: Dunn, Maria T. <maria.dunn@ncwildlife.org>
Cc: Beecher, Gary H CIV USARMY CESAW (USA)<Gary.H.Beecher@usace.army.mil>; Coburn, Chad
<chad.coburn@ncdenr.gov>
Subject: [External] City of Boiling Spring Lakes Dams Construction/Reconstruction Project - Requested Information
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Maria, Please find the attached additional information you requested pertaining to the proposed Boiling Spring Lakes
Construction/Reconstruction project. This letter is intended to be a supplement to the PCN that our office submitted on
January 29, 2021.
Let me know if you need any clarification or additional information. Thank you,
a
Jon Swaim
Project Manager
McGill Associates, P.A.
1240 19t" Street Lane NW, Hickory, NC 28601
T 828.328.2024
C 828.434.0951
ion.swaima-mcgillassociates.com
mcgillassociates.com
m�gdl
February 3, 2021
Ms. Maria T. Dunn, Coastal Coordinator
NC Wildlife Resources Commission
943 Washington Sq. Mall
Washington, North Carolina 27889
RE: Dam Construction/Reconstruction Project
Requested Supplemental Information
City of Boiling Spring Lakes, North Carolina
Dear Ms. Dunn:
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This letter is in response to your request for additional information during our pre -
permitting meeting held on October 17, 2019. McGill submitted the Pre -
construction Notification (PCN) Form on January 29, 2021 requesting Clean
Water Act 401/404 verification for the proposed repairs to the Boiling Spring Lakes
dam system. Please find the below information pertaining to project purpose and
need, design considerations, alternatives analysis, and ecological benefits.
Purpose and Need Analysis, Design Considerations, Alternatives Analysis
Purpose and Need Analysis
The purpose of the proposed project is to re-establish the Boiling Spring Lakes
system by repairing the City -owned dams breached by Hurricane Florence in
2018. The lake system has historically been the lifeblood and identity of the City
of Boiling Spring Lakes community. Benefits for the local community and City if
lakes are restored:
1. Restoration of lacustrine fringe wetlands and open water — Large areas of
lacustrine and forested wetlands existed along the fringe of the lake
system prior to draining. The project would restore these wetlands and
shoreline areas which provide habitat for a variety of wetland and aquatic
animal and plant species. Approximately 353.3-acres of open water would
be restored if the lakes were returned to their original capacity.
2. Restore lakefront properties — At present there are 288 single family use
residential properties adjacent to the former lake system waterfront.
Restoring the waterfront would likely return these properties to their pre -
Florence value and worth.
3. Business growth — Several businesses and public service properties adjacent
to or near the lakes would benefit directly or indirectly from restoration.
MCGILL ASSOCIATES 1240 19`h STREET LANE NW, HICKORY, NC 28601 / 828.328.2024 / MCGILLASSOCIATES.COM
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Recreational opportunities provided by the lakes draw tourism to the area
which will benefit a variety of local businesses.
4. Recreation opportunities - The restored lakes will once again provide a number
of recreational and educational opportunities to both residents and visitors
of the City, including boating, waterskiing, hiking, wildlife and bird
watching, and fishing.
5. Flood control - Sanford Dam has historically been operated to lower the Boiling
Spring Lake level for flood control ahead of major storm events (McGill
2020).
Properties and Businesses Affected
Sanford Dam, North Lake Dam, and Pine Lake Dam were designed by Henry von
Oesen Consulting Engineers of Wilmington, North Carolina in 1960. Original
construction of the three dams was completed in 1961 and 1962 by the Lincoln
Construction Company of Wilmington, North Carolina. The three dams were
designed and constructed in support of the development of the Town of Boiling
Spring Lakes. According to the Boiling Spring Lakes Sinkhole Hazard Reduction
Plan (Planning & Design Associates, P.A. 1983), Boiling Spring Lakes was
originally designed in the late 1950s as a "planned retirement community" and
experienced the highest rate of population growth in Brunswick County between
1970 and 1980. The Town of Boiling Spring Lakes assumed ownership of the
three dams in March of 1981. The City is practically based around this lakes
system. Water levels were primarily maintained passively by the spillways for
aesthetics and recreational use throughout the lake system. Sanford Dam is also
operated to lower the Boiling Spring Lake level for flood control ahead of major
storm events (McGill 2020). Properties and businesses currently experiencing the
negative economic and aesthetic impacts of the loss of Boiling Spring Lakes:
- Public service properties and parks directly dependent on the Boiling Spring
Lakes system include North Lake Park, Alton Lennon Park, Tate Lake Park,
the Boiling Spring Lakes Community Center, and the Boiling Spring Lakes
Community Garden. North Lake Park is located just off E. Boiling Spring Road.
This waterfront park includes a fishing dock and bench swings. This park
allows leashed pets and there are year-round restroom facilities. Alton Lennon
Park is located near the corner of E. Boiling Spring Road and Alton Lennon
Road. This beautiful park includes a boat ramp for access into Boiling Spring
Lake, a newly renovated picnic shelter with tables, two bench swings,
MCGILL ASSOCIATES 1240 19`h STREET LANE NW, HICKORY, NC 28601 / 828.328.2024 / MCGILLASSOCIATES.COM
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and a great swimming area. Tate Lake Park is a small community park along
S Shore Drive which includes a shoreline natural area along Boiling Spring
Lake. The Boiling Spring Lakes Community Center currently consists of a
newly renovated fitness room with up to date equipment, a variety of classes
& instruction and serves as home base for many recreational programs for
youth, adult & senior adults, Community Center amenities also include the
Butterfly, Rose & Hummingbird Garden planted and maintained by the Boiling
Spring Lakes Garden Club, and a Nature Trail providing ecologic educational
opportunities in partnership with The N.C. Plant Conservation Program and
The Nature Conservancy. The Boiling Spring Lakes Community Garden
currently contains 14 raised planting beds for flowers, herbs and produce.
- Private commercial properties whose income is heavily affected or directly
depends on the lakes include the Lakes Country Club, Cougar County Disc
Golf Course, MW Marine Design, the Office Coffee and Wine Bar, Boiling
Spring Lakes Motel, Mama C's Taqueria, Kopps 2 Convenience Store, and
Sunoco Gas Station.
- According to Brunswick County GIS data, there are currently 535 residential
properties which adjoin the Boiling Spring Lakes system. Approximately 288
of those residential properties appear to be developed and currently in use as
single family residences. The majority of these properties are lakefront and
have a dock for boating access. Approximately 247 of these residential
properties are currently undeveloped. Returning the lake to original conditions
would return these homes and properties to pre -Florence value, increase
opportunities for land and home sales, and allow current and future
homeowners to enjoy their property as originally intended.
Importance of W Dam Road
The restoration of Upper Lake Dam is necessary to preserve the existence of W
Dam Road. This small locally used road provides an alternate route to the Antioch
community to the west, George II Highway SE to the east, and two large mostly
undeveloped residential properties along Sunset Road and W South Shore Drive.
Approximately 12 lakeside single family residential properties routinely utilize W
Dam Road as an alternate and low traffic option across Boiling Springs Lake.
Allen Creek
Allen Creek and its tributaries are the main recharge source for the Boiling Spring
Lakes system. Following the dam breaches, new channels began to form within
the lake beds. During site visits McGill observed the condition of these newly
aligned channels. The stream system was predictably degraded with no stable
bank vegetation to speak of beyond a sparse mixture of wetland and riparian
MCGILL ASSOCIATES 1240 19`h STREET LANE NW, HICKORY, NC 28601 / 828.328.2024 / MCGILLASSOCIATES.COM
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shrubs and grasses. Instream structure was non-existent and bed material
consisted of mostly unconsolidated sand, gravel, and shell material. Channel
sinuosity was observed as the stream flow had cut into loose lake bed material
leaving debris piles and large sediment deposits. Sediment deposition and
movement through the system was actively occurring within most observed
channel areas. Using available online aerial photography and based on site visits,
McGill estimates that approximately 44,120 linear feet (LF) of stream channel has
established since dam failure. Channel lengths totals:
Boiling Spring Lake (Main Lake) - 34,257LF
North Lake — 5,214LF
Pine Lake — 2,46OLF
Upper lake — 2,189LF
Design Considerations
During project design elements such as the standard design flood, site hydrology,
basin characteristics, rainfall characterization, and hydrologic modeling were
analyzed by McGill. Hydrologic and Hydraulic (H&H) models were developed to
simulate the lake system aiming to assess hydraulic performance for various
alternatives of all spillways. The H&H evaluation provided adequate spillway
sizing to ensure overtopping protection up to the design storm for each lake. In
addition, a combined breach of all dams upstream of Sanford Dam was simulated
to ensure that the breach of the upstream dams does not cause overtopping and
risk of failure at Sanford Dam. See attached Design Report, Hydrology and
Hydraulics section within the Pre -Construction Notification a -File. McGill
contacted NCDEQ — Division of Water Resources (DWR) to determine minimum
flow releases for the Dams. DWR reviewed the system and determined that a site -
specific study is not warranted for operating the dams as "run -of -river" (i.e.,
operated such that the outflow from each dam approximately equals inflow to each
impoundment). These "run -of -river" conditions will maintain downstream aquatic
habitat within Allen Creek, especially for the support of anadromous fish species.
No additional requirement for minimum flows is provided. The determination letter
from DWR is attached.
Alternatives Analysis
No Impoundment or Flow Control for North Lake, Pine Lake, and Upper Lake
Dams Alternative:
This alternative consists of repairing only Sanford Dam allowing a portion of the
MCGILL ASSOCIATES 1240 19`h STREET LANE NW, HICKORY, NC 28601 / 828.328.2024 / MCGILLASSOCIATES.COM
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main lake to refill to its normal (historic) water elevation of 30ft. This alternative
would result in less impacts to lake bed areas for construction, and allow for Allen
Creek and its tributaries to return to a stream channel structure in upstream areas
within Pine Lake, North Lake, and Upper Lake. However, with the Sanford Dam
normal water elevation at 30ft, the resulting water elevations within Pine Lake,
North Lake, and Upper Lake would be much lower than desired. The Pine Lake
and North Lake water elevation would be 5ft lower than original, and Upper Lake
water elevation would be 8ft lower than original. The upper three lakes at this
elevation would leave many existing private docks land locked, eliminating many
waterfront properties, and would leave virtually all of the upstream wetland and
shoreline areas drained. In addition, the continued release of sediment from
exposed lake bed areas would be an ongoing maintenance issue within the lake
and downstream into Allen Creek. Due to these undesirable issues, this
alternative was deemed impractical.
No -Action Alternative:
This alternative involves leaving the dam breaches as -is and not restoring the
impoundments. While this alternative eliminates the proposed impact to
jurisdictional areas from dam construction and the installation of spillways, it will
result in additional adverse impacts to historic open waters, and continued release
of sediment and bank/shoreline erosion downstream. While at full pool, the Boiling
Spring Lakes system contains State listed natural communities, and provides a
variety of habitat for native plant and animal species including several Federal and
State listed species (see Ecological Benefits of Lake Restoration section below).
In addition, the impoundments, which have been present in some shape since the
early 1960s, create a vital natural resource and identity for the community. It is
used for multiple recreational activities, directly contributes to home and land
sales, and provides economic benefits through tourism. Therefore, this alternative
was deemed impractical.
Construction/Reconstruction of Sanford Dam, North Lake Dam, Pine Lake Dam,
and Upper Lake Dam — Chosen Alternative:
The proposed designs are the culmination of several iterations of alternative
designs that aim to minimize the proposed work while maintaining public safety.
Ultimately, a Preliminary Analysis Report (PAR) was prepared as part of the NC
Dam Safety permitting process. The PAR identified the minimum spillway design
capacity needed to meet the requirements of NC Dam Safety, which also resulted
in the minimum required footprint which was the basis of design for this project.
The proposed repairs of the City -owned dams include restoration of the earthen
embankment and installation of spillways and seepage control elements that meet
current codes and standards. The design storm approved by NC Dam Safety
program is the'/2 PMP (Probable Maximum Precipitation) for the Sanford
MCGILL ASSOCIATES 1240 19`h STREET LANE NW, HICKORY, NC 28601 / 828.328.2024 / MCGILLASSOCIATES.COM
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Dam and '/3 PMP for the other dams in the system. The following are the major
elements included in the design:
— At Sanford Dam, install a cutoff wall for the entire length of the dam,
upgraded riser structure and cast -in -place (CIP) concrete box culvert to
replace the existing undersized spillway and rebuild the embankment at
the location of the breach and partially scoured area, and install mix -in -
place (MIP) panels along the upstream and downstream toes of the
embankment to mitigate the potential for cyclic liquefaction.
— At North Lake Dam and Pine Lake Dam, remove the existing bottom metal
culverts because they are not compliant with current codes and standards
and install riser structures and CIP box culverts with seepage controls.
— At Upper Lake Dam, replace the existing undersized spillway with a riser
structure and CIP box culverts with seepage controls and rebuild the
embankment at the breach.
Ecological Benefits of Lake Restoration
Since dam failure in 2018 lake system water levels have receded to the open
channel uncontrolled levels in Allen Creek and associated tributaries. Early
successional vegetation typical for disturbed rural areas has established including
native species and lawn management species such as dogfennel (Eupatorium
capillifolium), crabgrass (Digitaria spp.), fescue (Festuca spp.), soft rush (Juncus
effusus), sedges (Carex spp.), scutch grass (Cynodon dactylon), pine saplings
(Pinus spp.), and black willow (Salix nigra). Headwater or cove areas of North
Lake, Pine Lake, Upper Lake and several tributary areas along S Shore Drive and
W North Shore Drive have drained, dramatically altering the soils and vegetation.
These large areas have begun to convert from a forested wetland and typical
lakeshore open water system with established littoral and limnetic zones, to a
headwater stream system with a saturated sandy bed and upland banks. The
water level drainage in these areas has most likely produced major changes in
soil physical, chemical, and biological properties. The organic lake bed and
wetland soils developed under historic flooded conditions, and the resulting
accumulation of plant material over time likely resulted in increases of soil depth.
As these areas drained in 2018, the primary processes leading to the development
of their organic soils, i.e., flooding, were removed forcing the soil to change from
an anoxic (anaerobic) to oxic (aerobic) system (Wright and Reddy, 2001). With
these changes to the hydrology and soil, came changes to the vegetation and
habitat. Wetland and aquatic vegetation has begun to convert to more upland and
terrestrial vegetation as evident in the early successional plant species mentioned
earlier. As the lake system remains drained, it is our opinion that this trend will
continue further upstream as forested wetland areas adapt to these extreme
MCGILL ASSOCIATES 1240 19`h STREET LANE NW, HICKORY, NC 28601 / 828.328.2024 / MCGILLASSOCIATES.COM
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hydrologic changes. By restoring the dams to their original capacity and re-
establishing hydrologic conditions through flooding, these impacted areas should
quickly rebound and return to their historic function.
Loss of wetland and littoral habitat in these cove areas has most likely displaced
many wildlife species. Many vertebrate (e.g. mammals, waterfowl, fish, etc.) and
invertebrate (e.g. snakes, insects, etc.) use both the littoral zone as well as the
adjoining terrestrial ecosystem for food and habitat. Biota that are commonly
assumed to reside in the pelagic zone, including zooplankton and fish
(planktivores and piscivores) often rely heavily on resources from the littoral zone.
(Peters and Lodge, 2009).
According to US Fish & Wildlife Service, NC Wildlife Resources Commission, and
the NC Natural Heritage Program several Federal and State listed species and
natural communities have documented occurrences or have the potential to occur
within the lake system or within adjacent and upstream wetland areas
(Documented within project area or within 1-mile of project area) . See attached
IPAC and NCNHP reports within the Pre -Construction Notification a -File. These
species include but are not limited to:
Federal — Candidate Species
— Magnificent ramshorn (Planorbella magnifica). The magnificent ramshorn was
pushed out of its natural habitat and since 1993 remains in existence only in
captivity. If enough habitat is secured in suitable ponds and sustained into the
future, magnificent ramshorn snails could be released to repopulate their
historical habitat. The snail is adapted to still or slow -flowing aquatic habitats,
and lays eggs on spatterdock and lily pads.
Federal — Threatened Species
— Wood Stork (Mycteria americana). Wood storks use freshwater and estuarine
wetlands for nesting, feeding and roosting. They feed in wide variety of tidal
and freshwater ecosystems: freshwater marshes, ponds, hardwood and
cypress swamps, narrow tidal creeks or shallow tidal pools, and artificial
wetlands such as seasonally flooded roadside and agricultural ditches,
impoundments and large reservoirs. Particularly attractive feeding sites are
depressions in marshes or swamps where fish become concentrated during
periods of falling water levels. They nest in patches of medium to tall trees,
either in standing water or on islands surrounded by expanses of open water.
State — Threatened Species
— Savanna Indigo -bush (Amorpha confuse). Habitats include riverbanks, soggy
MCGILL ASSOCIATES 1240 19`h STREET LANE NW, HICKORY, NC 28601 / 828.328.2024 / MCGILLASSOCIATES.COM
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thickets, open bottomland woodlands, edges of marshland, and wet prairies
along rivers
- Brown Bogbutton (Lachnocaulon minus). This species grows in somewhat
similar habitats as with many other Lachnocaulon and Eriocaulon species --
damp sandy soil associated with pinelands. It grows at the margins of pineland
pools and ponds, in shallow ditches, along damp roadsides that are sandy,
and less so in wet pine savannas.
- Shrubby Seedbox (Ludwigia suffruticosa). This species is generally restricted
to shallow pools with often variable water levels, mainly in Iimesink ponds and
clay -based Carolina bays, which are rare and very small habitats on the
landscape, and thus it grows mainly in high -quality natural places. It might
grow in other shallow pools or wet spots in pine savannas, but normally in
good quality habitats.
- Horned Bladderwort (Utricularia cornuta) This bladderwort is typically found
on muddy shores and scrapes, shallow pond margins (such as Iimesink ponds
and clay -based bays), and occasionally in ditches.
State - Endangered Species
- Florida Spikerush (Eleocharis elongate) Sinkhole ponds or depression ponds,
blackwater stream impoundments and beaver ponds. May occur perched on
floating peat mats. Essentially only in "pool/pond" habitats.
State - Special Concern Species
- Venus flytrap (Dionaea muscipula). The species rarely occurs in seasonally
flooded depressions, although it may occur along the edges of such sites.
- Pigmy Rattlesnake (Sistrurus miliarius). The Pygmy Rattlesnake tends to live
in many different habitats such as: partially wooded hillsides, rocky hillsides,
pine woodlands, along riverbanks or streams, and in marsh or swamp areas.
Many times the Sistrurus miliarius can be found in underground burrows,
which were previously dug and used by other small animals. A characteristic
that all of these habitats have in common is that they all are very close to the
water.
- Yellow Fringeless Orchid (Platanthera integra). Savannas in the Coastal Plain,
bogs in the Mountains and Piedmont... Essentially endemic to the
Southeastern Coastal Plain.
- Eastern Chicken Turtle (Deirochelys reticularia reticularia). Locally, may be
found more often in ponds and ditches in pine savannahs.
State - Significantly Rare Species
- Coppery Emerald (Somatochlora georgiana). The Coppery Emerald relies on
small sandy streams and slow -moving creeks, often with acidic water, in
MCGILL ASSOCIATES 1240 19`h STREET LANE NW, HICKORY, NC 28601 / 828.328.2024 / MCGILLASSOCIATES.COM
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forested areas.
- Blackbanded Sunfish (Enneacanthus chaetodon). This fish is largely restricted
to quiet, shallow, heavily vegetated, nonturbid, darkly stained, slightly to very
acidic waters of sand- and mud -bottomed creeks, small to medium rivers,
ponds, lakes, and roadside drainage ditches.
Natural Communities, Natural Areas, and Managed Areas
- Natural Communities - Cypress -Gum Swamp (Blackwater Subtype), Pond
Pine Woodland (Typic Subtype), Sandy Pine Savanna (Rush Featherling
Subtype), Small Depression Drawdown Meadow (Typic Subtype), Small
Depression Pond (Open Lily Pond Subtype, Typic Marsh Subtype), Small
Depression Shrub Border, Wet Pine Flatwoods (Sand Myrtle Subtype),
Pine/Scrub Oak, Sandhill (Coastal Fringe Subtype), High Pocosin (Evergreen
Subtype), Xeric Sandhill Scrub (Typic Subtype)
- Natural Areas (Rated as Very High or Exceptional) - Boiling Spring Lakes
Limesink Complex, Blue Pond/Allen Creek, Orton Sandhills and Limesinks,
Boiling Spring Lakes Wetland Complex, Pretty Pond Limesink Complex
- Managed Areas - North Carolina Coastal Land Trust Easement, Brunswick
County Open Space, Boiling Spring Lakes Plant Conservation Preserve,
Pretty Pond Limesink Complex Natural Heritage Preserve, Boiling Spring
Lakes Preserve
It is the opinion of McGill Associates that the ecological benefits gained from
restoring the Boiling Spring Lakes system to its original open water condition far
outweigh the effects of land disturbing activities during construction. Lake
restoration will rejuvenate open water, upstream wetland, and lake shore
hydrology, recreating lost habitat for many wildlife species, eliminate downstream
sedimentation due to dam failure, and return the listed Natural Communities,
Natural Areas, and Managed Areas to their desired condition.
Rafaranrac
- J.A. Peters, D.M. Lodge. 2009. Encyclopedia of Inland Waters.
- McGill. 2020. "Preliminary Assessment Report." Alternatives Analysis.
- McGill. 2021. "Design Report, Dams Construction/Reconstruction Project,
City of Boiling Spring Lakes."
- Planning & Design Associates, P.A. 1983. "Boiling Spring Lakes Hazard
Reduction Plan."
- Wright, A.L., and K.R. Reddy. 2001. Heterotrophic microbial activity in
northern Everglades wetlands soils. Soil Sci. Soc. Am. J. 65:1856-1864.
MCGILL ASSOCIATES 1240 19`h STREET LANE NW, HICKORY, NC 28601 / 828.328.2024 / MCGILLASSOCIATES.COM
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Please find supplemental information regarding project structural analysis and
design, hydrology and hydraulics calculations and data, geotechnical analysis,
and construction considerations, sequencing, and scheduling in the PCN eFile
submittal. Also, please include McGill Associates on the copy list of all
correspondence for this project. If you have any questions regarding this
information, please contact me at 828-328-2024.
Sincerely,
MCGILL ASSOCIATES, PA
J�
JON SWAIM
Project Manager / Environmental Services
Enclosure: NCDENR Low Flow Correspondence Letter
Cc: Mr. Chad Coburn, NC Dept of Environmental Quality
Mr. Gary H. Beecher, US Army Corps of Engineers
Mr. Michael Hanson, PE, LEED, AP. McGill Associates
Mr. Dori Sabeh, PE, LISP, McGill Associates
P:\2020\20.07036-BoilingSprL-Dams Construction Reconstruc\Design\Permits
MCGILL ASSOCIATES 1240 19`h STREET LANE NW, HICKORY, NC 28601 / 828.328.2024 / MCGILLASSOCIATES.COM
ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
S. DANIEL SMITH
Director
Dori Sabeh, PE, GISP
McGill Associates, P.A.
5400 Trinity Road, Suite 107
Raleigh, NC 27607
NORTH CAROLINA
Environmental Quality
September 8, 2020
RE: Boiling Springs Lake Dam (BRUNS-003), Allen Creek, Brunswick County
Flow Requirement
Dea ir:
This letter is in response to your request for a determination of a flow requirement for the Boiling Springs Lake
(Sanford) Dam and near -by dams that sit within the footprint of the main impoundment, i.e., North Lake Dam
(BRUNS-001), Pine Lake Dam (BRUNS-002), and Upper Lake Dam (BRUNS-012). The dams were breached by
flood flows associated with Hurricane Florence in September 2018. The dams are subject to the Dam Safety
Law and associated rules. 15A NCAC 02K .0500, et seq., provides the process for establishing minimum flow
requirements for subject dams.
Because the impounded waters of Boiling Springs Lake reach up to the toe of each of the three dams that sit
within the footprint of the impoundment, those dams should be operated such that the outflow from each dam
approximately equals inflow to each impoundment, or "run -of -river."
For the following reasons the Division of Water Resources (DWR) requests that the Boiling Springs Lake Dam
be operated in a run -of -river mode of operation as well.
• Establishing a flow requirement for the dam would require a site -specific field study that would be a
challenge given the dam's location in the outer coastal plain and the associated topographic, geologic
and hydrologic characteristics of the watershed.
• Given that there appears to be no off -stream water usage, for all intents and purposes the dam will
spill water in a run -of -river manner. Thus, the commitment of staff time and resources and potential
cost to the dam owner does not seem justified at this time.
DWR will reconsider the need for a site -specific study at such time that off -stream uses put the run -of -river
mode of operation in jeopardy.
If you have questions or wish to discuss further, please contact me at 919.707.9029 or by email at
fred.tarver@ncdenr.gov.
Sincerely,
Fred R Tary r III
Water Planning Section
D E Q�� North Carolina Department of Environmental Quality I Division of Water Resources
512 North Salisbury Street 1 1611 Mail Service Center I Raleigh, North Carolina 27699-1611
NORTNcnaouNA
Department of Enelmnmental Quay �� 919.707.9000