20221671 Ver 1_RSP - DWR Comment Response Letter - March 2023_20230303

NC Depat tinent of Environmental Quality
Division of Water Resources
401 & Buffer Permitting Branch
ATTN: Katie Merritt, Acting Supervisor
N. Salisbury Street
1611 Mail Service Center
Raleigh, NC 27699-1611
March 3, 2023
SUBJECT: RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION
Woodfin Riverside Park (DWR#20221671)
Dear Ms. Merritt,
On January 5, 2023, The Town of Woodfin received comments from Division of Water Resources in response to an
application requesting an Individual Water Quality Certification from the Division for the subject project, which was
submitted on December 1, 2022. Below, we provide an official response to those comments in red text; standalone items
requested by the Division and referenced in our responses are attached to this letter.
1. If the U.S. Army Corps of Engineers (USACE) requests a response to any comments received as a result of the
Public Notice, please provide the Division with a copy of your response to the USACE.
No public comments were received during the Public Notice period, therefore no request for comment response
was made by USACE.
2. Staff from the Division attended a pre -application meeting on April 21, 2022, regarding the subject project at
which time several documents were provided including a PowerPoint presentation entitled 20220415 Interagency
Meeting Presentation and a memo dated April 20, 2022 regarding Fish Passage Specifications for Woodfin Wave
Whitewater Park (memo). The Division received an update to the memo dated August 2, 2022. Among other
things, the PowerPoint summarizes modeled velocities and shear stresses within the French Broad River
associated with the wave feature under various flow regimes. Neither the memo, nor the results of the modeling,
were included with the application. Please confirm the information provided in the referenced documents is
applicable to the current design and/or summarize the results of any further model/design refinement that was
incorporated into the final design and that varies from the aforementioned documents.
The 2D model was re -run with the final design surface and boulder cluster layout. The results are presented in an
updated memo dated March 3, 2023 by senior fisheries ecologists Ashley Ficke and Chris Craft of GEI
Consultants. The memo is attached to this response document.
3. Please provide a French Broad River stage/discharge monitoring and contingency plan to be implemented during
in -river construction activities. The plan should include a protocol to monitor weather and river stage and/or
discharge and provide for contingencies should a high discharge event occur. The plan should include details on
the design discharge for the cofferdam and actions to be taken should a flow event that exceeds the height of the
cofferdam occur.
Please see attached general high water contingency plan. Please note that the selected contractor will be
responsible for maintaining water control and developing a detailed contingency plan including weather
monitoring, chain of command, etc. The in -stream design engineer can provide supporting hydrological data and
modeling results.

4. The Division accounts for impacts to streams in length. Please revise the Wave and Bypass Impact Table to
include impact lengths.
The table has been revised accordingly and is attached.
5. The Site Plan Sheet L1.3 calls for a Mud Play Area within the unnamed tributary (UT) of the French Broad
River. It's not clear what the Mud Play Area entails. Please provide a narrative description and any applicable
design plans for the Mud Play Area, including how water quality standards will be maintained and how the
stream will be protected from degradation so that the Division can adequately review and determine whether the
project will cause or contribute to a violation of water quality standards and/or comport with the state's
antidegradation policy.
L1.3 has been adjusted to define the amenity more accurately. A boulder with a depression in it (See detail
3/L8.9), will be tucked into the slope and potentially used as a natural play element. Rainwater will collect in the
depression and play sand can be used to make mud.
L1.3
•
BOULDER RETAINING WAIL
Mud sink detail from L8.9
ROCIOPOURED CONCRETE WITH BOWL TO OLT AS
MUD HITCH EN IF POURED C ONG RETEIS USED. POUR
CONCRETE N BEPHEEN NATUR, BOULDERS TO KEY
IQTCHEN BOWL INTO BOULDERS.
1. BOWL SHALL BE BROAD AND SHALLOW TO ALLOW
EAST SCOOPING OUT OF SEDIMENT WI. SHO VEL OR
BROOM
DESION-HUILD BY CONTRACTOR USE IMAGE AS
GUIDE OF INTENT OF USE
DEMON TO BE SH ARED WITH LAN DSC APE
ARCHITECT PRI. TO INSTALLATION
MUD KITCHEN

6. Please provide additional design/construction details, including proposed cross -sections, for the upstream river
access and bank stabilization; the whitewater wave, bank treatment, and beach; and the boulder toe and
downstream boat ramp. The design details should include the shape and form of the wave feature and bypass
channel including boulder clusters, low -flow notch, etc. described in the memo.
Please refer to updated 90% design drawing plan set.
7. The Site Plan Sheet L1.3 has a call -out for a Boulder Toe Bank Stabilization to Double as River Access feature.
However, this feature is not included in the impact table, nor are construction details provided. Please confirm
this feature is to be constructed above the ordinary high water mark, or include it in the impact table, provide
justification for the feature, and provide construction details.
This feature will be constructed above the ordinary high water mark.
8. Please provide additional details regarding how the abandoned bridge pilings are attached to the river bottom,
what they are constructed of, and how they will be removed.
We have not uncovered any primary source information on what specific materials comprise the pilings and how
exactly they are attached to the river bottom. However, Marc Hunt, a project proponent and recreational boater,
accessed them via kayak during low water, evaluated them in situ, and provided us with notes and photographs.
Based on the information Mr. Hunt provided, our current understanding is that they are timber cribbing filled
with riprap/cobble; there does not appear to be any metal/rebar used to hold them in place. As such, the plan
currently is to remove the cribbing with an excavator as the temporary low water road is removed. If during
closer inspection any metal/rebar is found to be doweled into bedrock, it will also be removed by excavator (a
hoe -ram attachment can be used on an excavator if needed to break out rebar) to ensure the safety of river users.
9. Sheet WWEC.4 indicates the upper river access and bank stabilization work will be constructed in the wet.
However, the WOTUS Impacts Narrative indicates the south access including boulder toe/bank stabilization will
be constructed by surrounding the area with a cofferdam and dewatering. This area must be constructed in the
dry. Please revise Sheet WWEC.4 to include details showing how these features will be constructed while
avoiding excavation in flowing water.
Revised Sheet WWEC.4 is attached.
10. The typical cofferdam water control detail on sheet WWEC.6 appears to depict settling ponds constructed outside
of the cofferdam, but within the river footprint. Please revise the detail to depict the settling ponds in an upland
location.
Revised Sheet WWEC.4 is attached.
11 The General Erosion & Sediment Control Notes note 4 on Sheet WWEC.6 indicates dewater pump discharge
from within the cofferdams will be discharged onto the floodplain away from wetlands and construction
activities. However, the details on Sheets WWEC.2, WWEC.3, and WWEC.5 appear to depict the pump
discharging directly to the river. Please confirm that the dewatered pump discharge from all cofferdams will be
pumped to an upland location and treated further prior to discharge to the river. Please note energy dissipation
measures may also be required prior to release of water to the river. Please revise Sheets WWEC.2, WWEC.3,

and WWEC.5 to depict the pump discharge outlet in uplands or include a call -out on the plans that specifies this
requirement.
Erosion Control drawings have been revised to show discharge from dewatering activities along both banks to an
upland location for further treatment. For the mid -channel work area (WWEC.2), running a discharge hose to
either bank would be very challenging, and the use of a filter bag and/or discharge to settling ponds built from
super sacks just outside the dry work area is proposed. Drawing WWEC.2 will be updated based on DEQ
preference/response.
12. Please describe the lifespan of the wave feature, any anticipated maintenance of the feature, and how the
maintenance will be conducted.
Please refer to attached maintenance plan and inspection checklist.
13. The project is subject to post -construction stormwater review under the Phase II Stormwater Program. What
entity will be reviewing the project for compliance with post -construction stormwater requirements?
Buncombe County will be reviewing the project for compliance with post -construction stormwater requirements.
14. Please copy the Division on any response to the North Carolina Wildlife Resources Commission comment letter
dated January 4, 2023.
Noted; we will copy the Division on our response to the January 4, 2023 NCWRC comment letter.
We appreciate your consideration of the above responses and attached information. Please do not hesitate to contact me
with any questions or further requests for information.
Sincerely,
w- 0/
Owen Carson, Botanist / Senior Ecologist
Equinox
37 Haywood Street, Suite 100
Asheville, NC 28801
[phone] extension 204

Consulting
Engineers and
Scientists
Memo
To: Dane Palmer and Riley Adams, S2o Design and Engineering
From: Ashley Ficke and Chris Craft, GEI Consultants
Cc: Scott Shipley, S2o Design and Engineering
Date: March 3, 2023
Re: Fish Passage Specifications for Woodfin Wave Whitewater Park
GL I Consultants
INTRODUCTION
The French Broad River supports a highly diverse aquatic community. The fish assemblage
currently contains approximately 31 species from seven families, but 35 additional species
are either present in upstream stream reaches or tributaries or were historically present and/or
are being reintroduced to the system. The French Broad River also supports two mussels of
conservation concern: the Federally Endangered Appalachian Elktoe (Alasmidonta
raveneliana) and Creeper (Strophitus undulatus), a North Carolina State Species of Special
Concern. All mussels have parasitic larvae and rely on fish hosts to complete their life cycles.
Appalachian Elktoe targets specific fish species as hosts, whereas Creeper are generalists.
An increased interest in river systems in urban areas has led to a subsequent increase in
riverfront revitalization projects. Many of these projects include whitewater parks (WWPs).
Whitewater parks have the potential to disrupt fish movements, although they are not
typically as problematic as dams and grade control structures. Consideration of fish passage
needs during the design process can often alleviate the potential for whitewater parks or
specific features within these parks to function as barriers to fish passage. GEI was retained
by S2o Design and Engineering to develop specifications for the fish bypass in the Woodfin
Wave WWP, to allow upstream passage of the diverse resident fish assemblage.
METHODS
The best opportunity biologists have to provide design specifications for whitewater parks
lies in searching and synthesizing the abundant literature on fish swimming performances. To
maximize the probability of successful fish passage, the resident fish assemblage can be
categorized into swimming "guilds." These guilds consist of groups of species that have
similar swimming performances and behaviors, and therefore similar requirements for fish
passage. Once the guilds are developed, specifications for hydraulic characteristics such as
depth, velocity, and turbulence can be tailored for the guild with the most exacting
specifications for each characteristic. For example, a "big river fishes" guild containing
species that avoid shallow water can be used to set minimum depths at low flows, and a
"small -bodied fishes" guild can be used to develop recommendations for shallow, wetted
margins that would allow them to move upstream. In a situation where the fish assemblage is
species -rich, each guild may incorporate large numbers of species. Alternatively, a guild
might represent a single species in depauperate headwater systems.
Memo Page 1
GEI Consultants, Inc.
4601 DTC Boulevard, Suite 900, Denver, CO 80237
303.662.0100 fax: [phone]
www.geiconsultants.com

till Memo 1 Page 2 March 3, 2023
S2o Design and Engineering
The following fishes were chosen as representative species for each swimming guild.
Selection of these species was based on availability of swimming performance data, presence
in the French Broad River, and ecological significance of the species. The species list
provided by the State of North Carolina and the guilds that were developed for them are
included in an attachment at the end of this document.
Small -bodied fishes: The swimming abilities of 16 common North American fishes from
seven families were used to develop representative specifications for small -bodied fishes.
The slowest of these species were Stonecat (Noturus flavus) and Johnny Darter (Etheostoma
nigrum), both of which were capable of sprinting at approximately 2 ft/s (Ficke 2015).
Mottled Sculpin (Cottus bairdii) was also considered during development of specifications.
This species is not known to be present in the project area, but it is a host for Appalachian
Elktoe (NCWC 2021), so providing for passage of this species was essential. This species
can sprint for extremely short distances at nearly 3 ft/s (Aedo et al. 2009), but its sustained
swimming ability is limited by large fins, which produce substantial drag (e.g., Webb 1998).
Mottled Sculpin are benthic and can use several station -holding techniques to rest when
challenged by high water velocities (Aedo et al. 2009).
The available data on swimming performance for small -bodied species that are surface -
oriented suggest that their swimming and sprinting abilities are similar to those of other
small -bodied species that have different water column preferences. For example, Inland
Silverside (Menidia menidia) can swim at approximately 10 body lengths/second
(approximately 1 ft/s) for prolonged periods (i.e., up to 25 minutes, Arnott et al. 2006).
Western Mosquitofish (Gambusia affinis) can swim at similar relative speeds; their
swimming ability is somewhat lower than other tested species (sprinting speeds of
approximately 1 ft/s, Li et al. 2017) because of their small sizes. The swimming abilities of
these two species are comparable to those of other small -bodied species with documented
prolonged swimming and sprinting performances (e.g., Ficke 2015, Prenosil et al. 2016).
Studies involving multiple small -bodied fishes tested under the same conditions indicate no
substantial difference between the swimming performance of small -bodied species with
different preferences for water column position. Therefore, top -water specialists such as
Western Mosquitofish and Inland Silverside were included in the guild with the remainder of
the small -bodied species.
Fortunately, most small -bodied fishes will utilize shallow, low -velocity water on channel
margins if main channel velocities are challenging (e.g., Schwartz and Herricks 2005).
Continuous pathways with water velocities between 0 and 2 ft/s within the fish bypass will
allow fish passage for this guild.
Anguilliform swimmers: Lamprey are anguilliform or "eel -like" swimmers; this mode of
swimming is less efficient. Pacific Lamprey (Entosphenus tridentatus) was used as a
surrogate species in absence of available swimming data for the three native lampreys
1 Although adult Western Mosquitofish are smaller (and thus slower) than adults of many other species native to
the French Broad River, they should still be able to utilize the slow, shallow margins of the fishway, where
depth -averaged velocities range from 0 — 2 ft/sec.

kel Memo l Page 3 March 3, 2023
S2o Design and Engineering
currently and historically present in the watershed. A 200 mm Pacific Lamprey2 can swim at
2 ft/s for an average of 38 seconds (DiRocco and Gervais 2021; Katopodis and Gervais
2016). Because of their eel -like shape, these fishes would be able to use the same shallow,
low -velocity water to ascend the fishway as the small -bodied fishes.
Sunfishes: Smallmouth Bass (Micropterus dolomieu). The swimming ability of this sought-
after native game fish has been well -documented. This species is also ecologically significant
because it serves as a host for multiple mussel species. The remaining sunfishes in the project
area were included in the small -bodied fishes guild because of their smaller size and limited
swimming abilities (e.g., Jones et al. 2011). Smallmouth bass in voluntary studies involving a
large raceway (over 150 ft. in length) showed that upstream passage success and the
probability that fish would try to move upstream decreased dramatically as water velocities
exceeded 4 ft/s (Peake and Farrell 2005). Therefore, availability of water depths of 1 ft or
more (to provide sufficient depth for large individuals) and velocities of 4 ft/s or less will
allow passage for this species.
Fusiform river fishes: Because its swimming ability is well -studied, White Sucker
(Catostomus commersonii) was used to develop specifications for larger, fusiform (i.e.,
streamlined) river fishes, such as suckers and large minnows. Adults can sprint for
approximately 60 s at 10 body lengths per second (BL/s, Castro -Santos 2005). This indicates
that adult White Sucker can negotiate the bypass if water velocities are less than 6 ft/s over a
distance of 40 ft. Therefore, if bypass specifications for Smallmouth Bass are met, White
Sucker will also be able to utilize the bypass.
This guild also includes a number of redhorse species (Genus Moxostoma). The swimming
performance of these species is poorly studied, but one study of intraspecific comparisons
was available. The slowest of the three species, Silver Redhorse (M. anisurum) was able to
swim at 2 — 3 body lengths per second for an approximate median of 100 s (Hatrey et al.
2014). Thus, an adult Silver Redhorse that was 300 mm long should be able to swim at
velocities of approximately 2 ft/s. However, the tests used in this study probably also
underestimated swimming ability, because all three redhorse species have been able to
successfully ascend a vertical slot fishway, which generally requires short periods of
negotiating high water velocities.3 Nevertheless, if fishway water velocities of 0 — 2 ft/s at
depths of 1 ft should allow passage of the redhorses present in the French Broad River.
Redhorses are also benthic, or bottom -oriented species, so they would likely be able to
negotiate depth averaged velocities greater than 2 ft/s, because water velocities tend to be
lower near the substrate, particularly in hydraulically rough channels (e.g., Knighton 1988).
Big River Fishes: Specifications for big river fishes were developed using studies of
sturgeon in prototype fishways. Lake Sturgeon (Acipenser fulvescens) are present in the
project area, and reintroduction of Paddlefish (Polydon spathula) has begun in the watershed.
Therefore, specifications that allow passage of this species are critical to project success.
Adult Shovelnose Sturgeon (Scaphirhynchus platorhynchus) in U.S. Bureau of Reclamation
2 While adults of this species attain lengths of nearly 900 mm, adults of the species in the Broad French River
do not usually exceed 200 mm in length (MDFW 2022; NDEC 2022; Williams and Williams 2005).
3 The primary goal of the study was to compare swimming ability between Moxostoma species, not numerically
estimate them.

titil Memo 1 Page 4 March 3, 2023
S2o Design and Engineering
prototype fishways could negotiate water velocities of 6 ft/s for 40 ft. with a 47% success
rate, and field studies of habitat preferences indicated that adults of this species will utilize
habitats with velocities of up to 6 ft/s (White and Mefford 2002). A 2007 study of fish
passage also indicated that White Sturgeon (A. transmontanus) could sprint faster than 6 ft/s
for short distances (Webber et al. 2007). No swimming performance data are available for
adult Paddlefish.
Sturgeon and Paddlefish should be able ascend the fishway if velocities between 4 and 6 ft/s
are available in the low -flow channel. However, the big river fishes guild also includes a
number of deeper -bodied fishes, such as Quillback and River Carpsucker, which may have
reduced swimming performance compared to more fusiform species. A 1982 study of
Missouri River fishes indicated that aerobic swimming velocities of Bigmouth Buffalo
(Ictiobus cyprinellus) and River Carpsucker (Carpoides carpio) were approximately 2 ft/s
(Schmulback et al. 1982). While no sprinting performance data are available for these
species, it is likely that their swimming abilities are underestimated, as commonly occurs
with studies conducted using swimming flumes (e.g., Peake and Farrell 2006). For example,
the aerobic swimming ability of Shovelnose Sturgeon was documented to be 2.5 ft/s in the
Schmulback et al. study, but volitional trials indicate that this species can negotiate much
higher water velocities for significant distances (see following section for details). Successful
passage of the deeper -bodied fishes in this guild was assumed if velocities of 2 — 3 ft/s
occurred at depths of 1 ft or more.
The recommendations for each guild described above were compared against 2D
hydrodynamic model output provided by S2o Design and Engineering to determine if
fishway specifications for all guilds were met for the proposed design. When specifications
were not met, GEI discussed with S2o, and the fish bypass design was revised accordingly by
S2o. This iterative process was used to develop the 60% design. The 60% design was
modified in response to comments received from the North Carolina Wildlife Resources
Commission using the same process and with updated fish passage specifications.
RESULTS:
FISH PASSAGE AT LOW FLOWS
Examination of current model output indicates that all specifications have been met for
passage of the fish guilds present in the project area (Table 1). The velocities shown below
(Figure 1) were modeled at a cross section that was midway between the top and bottom of
the fishway. This location was chosen because velocities are highest and depths lowest at this
location.
Small -bodied fishes and anguilliform swimmers: This cross section contains multiple
locations where water depths are between 0.5 and 1 ft and water velocities are less than 2 ft/s
(Figure 1a; Figure lb). This should allow passage of small -bodied fishes and anguilliform
swimmers.
Sunfish and fusiform fishes:
Water velocities less than 4 ft/s at depths of 1 ft or more are predicted to be present on the
margins of the low -flow notch of the bypass (Figure 1 a; Figure lb). The side slopes of the
bypass were decreased during a design revision so that the cross -sectional shape was more

pi Memo 1 Page 5 March 3, 2023
S2o Design and Engineering
trapezoidal than rectangular; this created a larger area of low -velocity water on each side of
the low -flow notch. Smallmouth Bass and fusiform river fishes should be able to utilize the
margins of the bypass to ascend it.
Big -river fishes: Sturgeon and paddlefishes should be able to utilize the fish bypass, even if
they are large enough to be restricted to the center of the low -flow notch. Water velocities
throughout the fish bypass do not exceed 6 ft/s at a flow of 1,000 cfs (Figure la; Figure lb).
To the extent possible, boulder clusters will be placed near the side slopes of the low -flow
notch to allow fish that prefer deeper water and slower water velocities. These will be placed
in a manner that allows fish to rest periodically while ascending the fishway, so they will not
become exhausted. For example, because sturgeon are known to move distances of 40 ft
against water velocities of 6 ft/s, boulder clusters will be installed every 20-30 ft to permit
frequent resting.
Table 1.—Predicted fish passage success for species representing the swimming guilds
develoued for the French Broad River.
Species
Guild
Successful Passage?
Stonecat, Johnny
Darter, Mottled
Sculpin
Small -bodied fishes
Yes — based on availability of water with velocities
between 0 and 2 ft/s on shallow margins of bypass
Pacific Lamprey
Anguilliform swimmers
Yes — based on availability of water with velocities
between 0 and 2 ft/s on shallow margins of bypass.
Adult Smallmouth
Sunfishes
Yes — based on availability of water with velocities
< 4 ft/s on bypass benches and on margins of low -
flow notch.
Bass
White Sucker
Fusiform fishes
Yes —based on availability of water with velocities
< 4 ft/s on bypass benches and on margins of low -
flow notch.
Lake Sturgeon
Big -river fishes
Yes — based on availability of water with velocities
< 6 ft/s in low -flow notch.

a, Memo Page 6
193S-
1934
1933
1932
193!
1930
1929
!0 l5 20 00
March 3, 2023
S2o Design and Engineering
— ;34)pll1-9EV9'19]042o22P1:_AM
A�
-- 24230111p3h02 ,W Fsflpas4c ?' n -
6a
4.0
20
30 15 +0 a 58
Sla3on 99Q
70 73 90 *0
Figure la. —Modeled velocities at a representative cross section of the proposed fish bypass at
1,000 cfs.
veledly oe'Elyptlf 33- Middle'
6-
5-
— reKKety'161PN20
C 5 10 •5 20 25 30 35 40 a5 50 55 60 65 70 75 ac 00
Sb9o, IPo
Figure 2b.—Modeled velocities at a representative cross section of the proposed fish bypass at
1,000 cfs.
FISH PASSAGE AT HIGHER FLOWS
95
SS

Memo Page 7 March 3, 2023
S2o Design and Engineering
The preceding fish passage predictions were based on examination of predicted conditions at
1,000 cfs. This flow is common throughout much of the year, including during much of the
spring spawning season, when directed migrations are more common. Further, discussions
with S2o staff suggest that velocity changes with an increase in flow to 1,200 or 1,400 cfs
would not have a substantial effect on water velocity. Thus, fish passage should occur over
most of the observed flow range in the project area.
At flows of 2,250 cfs, which are similar to expected median flows in the high flow months of
March and April, fish passage specifications were met for larger fishes, but they would have
had to use the shallower areas outside of the low -flow notch to ascend the fishway (Figure
2a; Figure 2b). Passage of small -bodied fishes and anguilliform swimmers would have been
limited to the margins of the areas outside of the low -flow notch. The reduced predicted
passage success at the structure at flows of 2,250 cfs led to structural modifications as
described in the following section.
Wacky against Tarraln lcolon1 on'6ygsa XS • MOdr'
1935-
,934-
1930-
1929 -
—J
—20230111-RES9'1614N2022023(Z00'
—'2023011 I_Ashierraln_FcMOSSageREW Grol
20 25 30 35 w 45 - i5 50 55 i0 75 BO BS 90 95
Figure 2a.—Modeled velocities at a representative cross section of the proposed fish bypass at
2,250 cfs.

a, Memo Page 8
Velocity on'Bypass x5 - Middle'
Suoon rill
March 3, 2023
S2o Design and Engineering
Figure 2b.—Modeled velocities at a representative cross section of the proposed fish bypass at
2,250 cfs.
MODIFICATIONS BASED ON FEEDBACK FROM NORTH CAROLINA WILDLIFE
RESOURCES COMMISSION
The original 60% design has been modified based on comments received from the North
Carolina Wildlife Resources Commission. Primarily, a different range of flows was
examined to ensure that fish passage was possible during a larger and more biologically
relevant range of flows. The new analysis focused on a flow of 2,250 cfs, which is similar to
the median flow during the months of March and April; additional flows were not modeled
because according to the 2D hydrodynamic models, fish passage efficiency was likely to
decrease as flows increase (due to higher velocities).
To improve fish passage efficiency at higher flows, the slope of the shallow areas outside of
the low flow notch was reduced from 3.5% to 1.75%, and the slope of the low flow notch
was reduced to 0.5% (Figure 3). Although water velocities remain high in the low flow notch
of the fishway, the increased depth in the shallow areas will allow its use by some fishes with
preferences for deeper water (Figure 4). For example, volitional fish passage trials indicate
that water depths of 1.5 ft are sufficient to facilitate passage of Shovelnose Sturgeon (White
and Mefford 2002).
The North Carolina Wildlife Resources Commission also requested that large roughness
elements/resting areas in the fishway imitate local geomorphology; specifically, it was
requested that rock ledges or shelves that protrude from the streambed be mimicked in the
fishway design. Thus, boulder rows were included in the fishway (Figure 5), as these are
analogous to rock ledges but do not create a rise in 100-year flood elevations or cause
unusual flow conditions in the fishway.

Memo I Page 9
March 3, 2023
S2o Design and Engineering
Figure 3. — Slopes of the low flow notch and the shallow areas in the revised bypass
design.
NEXT STEPS
The bypass would be constructed with boulders that were grouted to 50% of their height,
with the remainder of the void filled with native substrate. The presence of native substrate
and interstitial spaces would help increase the probability of successful passage for benthic
(i.e., bottom -oriented) species such as darters, Mottled Sculpin, and larger species such as
redhorses. However, the fishway will contain larger "roughness elements" such as boulder
rows and/or boulder clusters to facilitate passage at higher flows (Figure 5). These features
will provide resting opportunities, particularly for fish utilizing the deeper, higher -velocity
water in the low -flow notch. The type and placement of the roughness elements will be based
on a combination of hydraulic laboratory studies and field studies that provide information
on how to increase passage success.

Memo I Page 10
March 3, 2023
S2o Design and Engineering
Figure 4a.—Modeled velocities on the fish bypass, with boulder clusters, at 2,250 cfs.
1935-
1994 -
1933-
1930-
1929 -
10 15 2C
Velocity .y.in.t Tm.in kolonl an 'Bypass MS. Middle
50 55 60 B5
51211011 RI
75
202301 I 1-RE 1/13' 15188203 92:30120.
—WM111 A5h1main_E111'a161494BEV$' hole
BO 85
Figure 4b.—Modeled velocities at a representative cross section of the proposed fish bypass,
with boulder clusters, at 2,250 cfs.

Memo Page 11
March 3, 2023
S2o Design and Engineering
Raised Boulder
Fences 12"-18"
Protrusion
Figure 5. — Boulder "rows" added to the fishway to mimic local geomorphic conditions and
facilitate passage.

a Memo Page 12 March 3, 2023
S2o Design and Engineering
REFERENCES
Aedo, J., M. Belk, and R. Hotchkiss. 2009. Morphology and swimming performance of Utah
fishes: critical information for culvert design in Utah stream. Utah Department of
Transportation, Research Division, UT-09.12. Salt Lake City, UT.
Arnott, S. A., S. Chiba, and D. O. Conover. 2006. Evolution of intrinsic growth rate:
metabolic costs drive trade-offs between growth and swimming performance in Menidia
menidia. Evolution 60(6):1269-1278.
Castro -Santos, T. 2005. Optimal swim speeds for traversing velocity barriers: an analysis of
volitional high-speed swimming behavior of migratory fishes. Journal of Experimental
Biology 208:421-432.
Di Rocco, R, and R. Gervais. 2021. SPOT: Swim Performance Online Tools. Available
from http://www.fishprotectiontools.ca/.
Ficke, A. 2015. Mitigation measures for barriers to Great Plains fish migration. PhD
Dissertation. Department of Fish, Wildlife, and Conservation Biology, Colorado State
University, Fort Collins, CO.
Hatry, C., J. D. Thiem, T. R. Binder, D. Hatin, P. Dumont, K. M. Stamplecoskie, J. M.
Molina, K. E. Smokorowski, and S. J. Cooke. 2014. Comparative physiology and relative
swimming performance of three redhorse (Moxostoma spp.) species: associations with
fishway passage success. Physiological and Biochemical Zoology 87(1):148-159.
Jones, E. A., A. S. Jong, and D. J. Ellerby. 2008. The effects of acute temperature change on
swimming performance in bluegill sunfish Lepomis macrochirus. Journal of Experimental
Biology 211(9):1386-1393.
Katopodis, C, and R Gervais. 2016. Fish Swimming Performance Database and Analyses.
DFO Can. Sci. Advis. Sec. Res. Doc. 2016/002., 550. Available from http://www.dfo-
mpo. gc. ca/csas-sccs/Publications/ResDocs-DocRech/2016/2016_002-eng.html.
Knighton, D. 1998. Fluvial Forms and Processes: a new perspective. Hodder Education
Group, London. 400p.
Li, J., X. Lin, Z. Xu, and J. Sun. 2017. Differences in swimming ability and its response to
starvation among male and female Gambusia affinis. Biology Open 6:625-632.
MDFW. 2022. American Brook Lamprey Lethenteron appendix. Massachusetts Division of
Fisheries and Wildlife Natural Heritage & Endangered Species Program. Available online:
mass.gov/doc/american-brook-lamprey/download.
Michigan Natural Features Inventory (MNFI) 2004. Lampsilis fasciola fact sheet. Michigan
State University Board of Trustees.
https://mnfi.anr.msu.edu/abstracts/zoology/Lampsilis_fasciola.pdf. Accessed 10/21.
NDEC. 2022. Mountain Brook Lamprey. New York Department of Environmental
Conservation Species Assessment. Available online:
https://www.dec.ny.gov/animals/26031.html.

Et Memo Page 13
March 3, 2023
S2o Design and Engineering
Peake, S. J. and A. P. Farrell. 2005. Postexercise physiology and repeat performance
behaviour of free-swimming smallmouth bass in an experimental raceway. Physiological and
Biochemical Zoology 78(5):801-807.
Schmulbach, J. C., D. H. Tunink, and A. E. Zittell. 1982. Swimming performance of fishes
endemic to the Missouri River in South Dakota. Biological Services Program. U.S. Fish and
Wildl. Serv., Kearneysville, WV 107 pp.
Schwartz, J. S. and E. E. Herricks. 2005. Fish use of stage -specific fluvial habitats as refuge
patches during a flood in a low -gradient Illinois stream. Canadian Journal of Fisheries and
Aquatic Sciences 62:1540-1552.
Webb, P. W. 1998. Swimming. Pages 3-14 in Evans, D. H. (ed). The Physiology of Fishes,
2nd ed. CRC Press, Boca Raton, FL.
Webber, J. D., S. N. Chun, T. R. MacColl, L. T. Mirise, A. Kawabata, E. K. Anderson, T. S.
Cheong, L. Kavvas, M. McGee Rotondo, K. L. Hochgraf, R. Churchwell, and J. J. Cech Jr.
2007. Upstream swimming performance of adult white sturgeon: effects of partial baffles and
a ramp. Transactions of the American Fisheries Society 136:402-408.
White, R. G. and B. Mefford. 2002. Assessment of behavior and swimming ability of
Yellowstone River Sturgeon for design of fish passage devices. U.S. Bureau of Reclamation
Science and Technology Program.
Williams, M. G. and L. R. Williams. 2005. Conservation Assessment: Ohio Lamprey. USDA
Forest Service, Eastern Region. Available online:
http s ://www.fs.usda.gov/Internet/F SE DOCUMENTS/fsm91 _0543 81.pdf

E. Memo Page 14 March 3, 2023
S2o Design and Engineering
ATTACHMENT 1: FISH SWIMMING GUILDS, FRENCH BROAD RIVER

Consulting
Engineers and
Scientists
GEL..
Species
Family
Guild
Status
American Brook Lamprey
Petromyzontidae
Anguilliform
1
Ohio Lamprey
Petromyzontidae
Anguilliform
1
Lake Sturgeon
Acipenseridae
Big river
1
Quillback
Catostomidae
Big River
1
River Carpsucker
Catostomidae
Big River
1
Flathead Catfish
Ictaluridae
Big river
1
Paddlefish
Polyodontidae
Big river
1
Black Redhorse
Catostomidae
Fusiform River
1
Golden Redhorse
Catostomidae
Fusiform River
1
River Redhorse
Catostomidae
Fusiform River
1
Silver Redhorse
Catostomidae
Fusiform River
1
Smallmouth Buffalo
Catostomidae
Fusiform River
1
Smallmouth Redhorse
Catostomidae
Fusiform River
1
White Sucker
Catostomidae
Fusiform River
1
Smallmouth Bass
Centrarchidae
Fusiform River
1
Common Carp
Cyprinidae
Fusiform River
1
Creek Chub
Cyprinidae
Fusiform River
1
Grass Carp
Cyprinidae
Fusiform River
1
Chain Pickerel
Esocidae
Fusiform River
1
Muskellunge
Esocidae
Fusiform River
1
Channel Catfish
Ictaluridae
Fusiform River
1
White Catfish
Ictaluridae
Fusiform River
1
Brown Trout
Salmonidae
Fusiform River
1
Rainbow Trout
Salmonidae
Fusiform River
1
Northern Hogsucker
Catostomidae
Small -bodied
2
Green Sunfish
Centrarchidae
Small -bodied
2
Redbreast Sunfish
Centrarchidae
Small -bodied
2
Mottled Sculpin
Cottidae
Small -bodied
2
Bigeye Chub
Cyprinidae
Small -bodied
1
Blacknose Dace
Cyprinidae
Small -bodied
1
Blotched Chub
Cyprinidae
Small -bodied
1
Central Stoneroller
Cyprinidae
Small -bodied
1
Fatlips Minnow
Cyprinidae
Small -bodied
1
Golden Shiner
Cyprinidae
Small -bodied
2
Highland Shiner
Cyprinidae
Small -bodied
2
Longnose Dace
Cyprinidae
Small -bodied
2
Mimic Shiner
Cyprinidae
Small -bodied
2
Mirror Shiner
Cyprinidae
Small -bodied
2
1 = currently present in project area, 2 = present in vicinity of project area, 3 = not currently present
but reintroductions are planned or in discussion
Memo I Page 15
GEI Consultants, Inc.
4601 DTC Boulevard, Suite 900, Denver, CO 80237
303.662.0100 fax: [phone]
www.geiconsultants.com

Memo I Page 16
March 3, 2023
S2o Design and Engineering
Species
Family
Guild
Status
River Chub
Cyprinidae
Small -bodied
3
Saffron Shiner
Cyprinidae
Small -bodied
3
Silver Shiner
Cyprinidae
Small -bodied
3
Spotfin Chub
Cyprinidae
Small -bodied
3
Telescope Shiner
Cyprinidae
Small -bodied
3
Tennessee Shiner
Cyprinidae
Small -bodied
3
Warpaint Shiner
Cyprinidae
Small -bodied
3
Whitetail Shiner
Cyprinidae
Small -bodied
3
Brown Bullhead
Ictaluridae
Small -bodied
3
Flat Bullhead
Ictaluridae
Small -bodied
3
Banded Darter
Percidae
Small -bodied
1
Blotchside Logperch
Percidae
Small -bodied
1
Fantail Darter
Percidae
Small -bodied
1
Gilt Darter
Percidae
Small -bodied
2
Greenfin Darter
Percidae
Small -bodied
2
Greenside Darter
Percidae
Small -bodied
2
Logperch
Percidae
Small -bodied
2
Olive Darter
Percidae
Small -bodied
2
Redline Darter
Percidae
Small -bodied
2
Sickle Darter
Percidae
Small -bodied
3
Swannanoa Darter
Percidae
Small -bodied
3
Tangerine Darter
Percidae
Small -bodied
3
Wounded Darter
Percidae
Small -bodied
3
Mountain Brook Lamprey
Petromyzontidae
Small -bodied
2
Black Crappie
Centrarchidae
Sunfish
3
Bluegill
Centrarchidae
Sunfish
3
Largemouth Bass
Centrarchidae
Sunfish
3
Rock Bass
Centrarchidae
Sunfish
3
White Crappie
Centrarchidae
Sunfish
3
1 = currently present in project area, 2 = present in vicinity of project area, 3 = not currently present
but reintroductions are planned or in discussion

High Water Guidance for In -Stream Construction
Woodfin Wave at Riverside Park — Woodfin, North Carolina
This plan has been prepared to provide general guidance to the selected Contractor for use in determining
when it may be appropriate to enact a high-water contingency plan during construction of the Woodfin
Riverside Park in -stream scope. This document is intended to be a guide only and conditions must be
assessed in real-time using the best available data.
Proposed Construction Window
Hydrological analysis was completed using stream gauge data from USGS Station 03451500 at Asheville,
North Carolina. During the early design stages of the project this data was used for wave design and the
bypass channel and fish passage study. In addition, analysis was utilized to determine a preferred
construction window over the months with the statistically lowest average flow rates. The preferred
construction window was determined to be late July through October in a typical year. Average monthly
flows from historical gauge data are presented in the figure below.
3,000
2,500
2,000
v 1,500
0
1,000
500
French Broad River Monthly Mean Discharge
(USGS 03451500 AT ASHEVILLE, NC)
2 690
2,550
2,200
1,000
1,590
1y90 •55C 1,510
Jan Feb Mar Apr May Jun Jul Aug Sep
Figure 1 - Average Monthly Discharge (French Broad at Asheville)
318 McConnell Dr I Lyons I CO 180302
2,34C
Oct Nov Dec
1

Iig
Water Control
Erosion control plans have been produced and include a suggested water control configuration for
construction. These plans envision the use of multiple super sack cofferdams to dry out the work areas in
three different phases. Size, quantity and configuration of the super sacks shown in erosion control
drawings are conceptual only and will vary from actual site conditions. The selected contractor is
responsible for determining appropriate size, quantity and configuration of super sacks and/or other
means of water control to bypass flows around the work area and complete construction activities. Super
sack installation and layering may vary. Approximate flow depth at 1500cfs is 3-7ft depending on location
in the river (see Figure 4 below). The contractor shall maintain a minimum of 1ft of freeboard at all times
while construction is underway. The contractor shall adjust the installation as needed to maintain
freeboard during changing flow conditions or implement the High Water Contingency Plan to secure the
jobsite prior to inundation during high water events.
As part of the contractor selection process, other requested water control methods may be considered
based on contractor expertise and any requested changes to water control methods or configuration will
be submitted to regulatory agencies prior to construction.
Figure 2 - Example Phase of Water Control
Super sack cofferdams are anticipated to be 2 to 4 sacks high depending on location. The recommended
super sack row configuration is pyramidal (i.e. bottom row is 3 sacks wide, next row is 2 sacks wide, top
row is 1 sack wide) and example details can be found in the erosion control drawing set.
2
318 McConnell Dr I Lyons I CO 180302

Mq
Figure 3 - Super Sacks
Figure 4 - Water Depths at 1500cfs +/-
High Water Planning
As flows increase to 3500cfs, modeling shows the approximate depths around the construction site
increase to 4-9ft which is likely the upper threshold for in -stream work unless the contractor has proposed
an alternative method of water control and design from a supplier. The point at which this upper threshold
3
318 McConnell Dr I Lyons I CO 180302

is reached, the selected contractor would need to have their contingency plan executed (i.e. equipment
and materials out of the work area by the time the river reaches this level).
Based on historical data, it is likely that 3500cfs WILL BE exceeded at some point in the construction
window during large rain events, and the selected contractor will be expected to develop a High Water
Contingency Plan prior to starting construction. This plan will need to outline how the contractor will
efficiently secure the job site including removal of personnel, materials and equipment from the river in
the event that water levels begin increasing or if significant precipitation is forecasted. Additionally, the
plan will need to include a method of monitoring the meteorological forecast and a chain of command
and notification system to execute the contingency plan.
A general rule of thumb would be for construction crews to be on alert if 0.5" or more precipitation is
forecasted in the next 24hrs and that the jobsite be secured if 1.0" or more of precipitation is forecasted
in the next 24hrs. In addition, long term forecasts should be consulted regularly, and jobsites left secure
at the end of each work day in case of an unexpected rise in water levels overnight. For critical tasks such
as concrete placements, work should not begin unless the 3-day forecast is clear with little to no
precipitation expected. As stated above, the final plan details will need to be proposed by the selected
contractor and reviewed by the town and engineer. S20 will support the contractor with hydrological data
and modeling results as needed.
4
318 McConnell Dr I Lyons I CO 180302

Riverside Park Impact Table
Impact
Type/Reason
Permanent/No
Loss (LF, ac.)
Permanent /
Loss of Waters
(LF, ac.)
Temporary (LF,
ac.)
Total Impacts
Cut
(cy)
Fill
(cy)
P1
Culvert (S2)
17 If / 0.003 ac
(158 sf)
20 If /0.001 ac
(48 sf)
37 If / 0.004 ac
----
----
P2
River Access
(upstream)
143 If / 0.014 ac
(594 sf)
----
38 If /0.093 ac
(4,067 sf)
181 If / 0.107 ac
----
27
P3
Boat Ramp
(downstream)
37 If / 0.008 ac
(362 sf)
----
17 If /0.015 ac
(689 sf)
54 If / 0.023 ac
----
11
Total
180 LF / 0.022 ac
17 If / 0.003 ac
75 If / 0.109 ac
----
38
Wave and Bypass Impact Table
Impact
Type/Reason
Permanent/No Loss
(If, acreage)
Permanent/Loss of
Waters (acreage)
Temporary
(acreage)
Total
Cut
(cy)
Fill (cy)
W1
Wave &
Bypass Fill
0.760 ac (33,123 sf)
0.027 acre (1,185
sf)*
355 LF^
1.932 ac (84,161 sf)**
355 LF,
2.719 ac
396
4,079
W2
Construction
Access
0.262 ac (11,408 sf)
405 LF^
405 LF,
0.262 ac
521***
W3
Boulder Toe
River Left
0.019 ac (842 sf)
161 LF^
161 LF,
0.019 ac,
91
Total
161 LF, 0.779 ac
355 LF, 0.027 acre
405 LF, 2.194 acre
917
4,170
*0.027 acre of open water will be permanently filled/considered a loss of water due to construction of bypass channel 'island' and elevated tie -
ins on bank that will be permanently above Ordinary High Water Mark E evation of French Broad River (see Impact Summary Map).
**Dewatering will occur in phases through construction of 3 cofferdams (see attached plans).
***Once construction is completed, pre-existing piers will be removed/excavated.
^Length calculated using the maximum length of the areal impact measuring parallel with the river.

]FHA
SPHA
TRASH/RECYCLING, TYP.
DOG WASTE STATION, TYP.
Ss
ss
Ss
Ss
ACCESS PATH
BOULDERS
HEADWALL
'11111POCII-- ail
Poo FCC
FCC
\ FCC
\ FO
CMC _
\CMC \
INING WALL
MO
MC
MO
Know what's below.
CaII before you dig.
MO
EX. PILE TO REMAIN
WITH NEW SIGNAGE
BEACH (BY OTHERS)
BOULDER RETAINING WALL
CONCRETE PATH
BENCH
ss
ss
N
AMC C
dHj
dais NATURAL SURFACE TRAIL
BOULDER SEATING
TING LEGEND
O
— FOC —
0
BOULDER RETAINING WALL
SAFETY RAIL
CULVERT
CONCRETE PATH
. WETLAND
URFACE TRAIL
PROJECT BOUNDARY
DECIDUOUS TREE
DEAD TREE
AREA LIGHT
UTILITY POLE
GUY ANCHOR
ELECTRIC/CABLE PEDESTAL
DROP INLET
SEWER MANHOLE (SMH)
SEWER CLEAN OUT
FIBER OPTIC CABLE
WATER METER
GAS PEDESTAL
STREAM GAUGE
EXISTING WETLAND
no
ow
SS
SFHA
- FOC
OHW —
TB —
— TRANSITION FROM NEW TO
EXISTING ASPHALT PAVING;
SMOOTH & FLUSH
INTERPRETIVE SIGN
SITE BOULDERS, TYP.
CONS
WETLAND
a3ddne
GREENWAY WAYFINDING
ASPHALT GREENWAY
ifr
S
(tiwy F
257) oRi
1'F
BU-rER
MINOR CONTOUR
MAJOR CONTOUR
FENCE LINE
OVERHEAD WIRE
SANITARY SEWER
SPECIAL FLOOD HAZARD AREA
UNDERGROUND FIBER OPTIC CABLE
ORDINARY HIGHWATER MARK
TOP BANK
TREE LINE
RAILROAD TRACKS
CRAGGY MOUNTAIN LINE EASEMENT
30' STREAM BUFFER
PROPOSED LEGEND
0 0 0
o �
w
ASPHALT
CONCRETE
GRAVEL
PERMEABLE PAVERS
WATERLINE
BOULDER TOE BANK STABILIZATION TO DOUBLE AS RIVER ACCESS
BENCH
EX. ASPHALT PATH (RESURFACED)
BENCH SWING, TYP.
aft sum-
PICNIC TABLE, TYP.
GRILL, TYP.
DOG WASTE STATION, TYP.
TRASH AND RECYCLING, TYP.
PLANTED
DEPRESSION
EX. WETLAND
,2.,,,,,,,
i
.
i
TRANSITION FROM NEW TO
EXISTING ASPHALT PAVING;
TIE IN SMOOTH & FLUSH
*kJ
•z•
UPDATED PICNIC AREA
TRANSITION FROM NEW TO
EXISTING ASPHALT PAVING;
SMOOTH & FLUSH
ASPHALT PATH
STORMWATER SWALE
BOULDER RETAINING
TIM: ER STAIR
7 NAT
SURF `CETRAIL
/ •
EX. WETL
•
•
•
•
•
•
•
CONSTRUCTED WETLAND
0
N
SCALE: 20'-0"
Illessoft
sS
•
ilissave
EXPANDED PARKING
10' 20'
40'
--............._
EQUINOX
37
Asheville,
Haywood
t 828.253.6856
f 828.253.8256
`�
St.
Suite 100
NC 28801
SEAL
kA CAR',,
.!L•••PNDSc O<' .
* ;N 1542 =: *
_ :U
O Y GZ,'
Leo• ..P..•••;�J,
DESIGN BY:
DRAWN BY:
CHECKED BY:
w
1-
0
REVISIONS
I
Town of Woodfin
RIVERSIDE PARK
Woodfin, NC
Copyright© 2023, Equinox Environmental
Consultation & Design, Inc.
PHASE
90%
DATE
March 3, 2023
DRAWING SCALE
AS SHOWN
NOTE: If this drawing is not 24x36" it has been revised
from its original size and the scales noted on
drawings/details are no longer applicable.
DRAWING NAME
SITE PLAN
• 3
NATU
STEPPING STO

CD
0
0
H
0
U
Z
0
55
0
W
U
Z
Z
LL
0
0
O
II
II
EROS 0\ CO\TROD SEQ,E\C
PHASE 3
PROCEED AS FOLLOWS:
1. INSTALL LOW WATER ACCESS TO CENTRAL WORK ZONE IN THE WET
FROM RIVER RIGHT BANK UTILIZING CULVERTS BETWEEN
ABANDONED RAILROAD BRIDGE HERS TO BUILD TEMPORARY ROAD.
2. INSTALL COFFERDAM FOR WATER CONTROL IN CENTRAL WORK
ZONE USING SUPER SACK CONSTRUCTION DETAIL PROVIDED IN
WHITEWATER PLAN SET. SUPER SACKS TO BE FILLED WITH GRAVEL
OR SMALL COBBLE BASED ON CONTRACTOR PREFERENCE.
3. ALLOW WATER WITHIN ENCLOSED WORK AREA TO SETTLE PRIOR TO
PRELIMINARY PUMP DOWN OF WORK AREA.
4. INSTALL SUMP IN LOW CORNER OF CLOSED OFF WORK ZONE AND
INSTALL INLET PROTECTION MEASURES SHOWN IN WHITEWATER
PLAN SET DETAILS. INSTALL ADDITIONAL MEASURES SUCH AS SILT
FENCE OR SETTLING PONDS AS NEEDED TO MINIMIZE TURBIDITY OF
WATER PUMPED BACK INTO THE RIVER FROM THE SUMP.
5. ONCE WATER CONTROL AND EROSION CONTROL MEASURES ARE IN
PLACE AND FUNCTIONING PROPERLY, COMPLETE CONSTRUCTION OF
NOTE 1: THESE PLANS ILLUSTRATE THE SUGGES*ED WATER
CONTROL AND CONSTRUCTION PHASING TO COM LETE THE
IN -STREAM WORK SCOPE. ANY DEVIATION FROM ESE PLANS
REQUESTED BY THE CONTRACTOR MUST BE SUB ITTED TO THE
ENGINEER FOR APPROVAL BY PERMITTING AGENCIES.
o
NOTE 2: THE WEATHER FORECAST SHOULD BE MON TORED
CLOSELY PRIOR TO AND DURING ALL IN -STREAM WO K. IT IS
ESSENTIAL THAT CONCRETE PLACEMENTS BE COMPLETED
DURING LOW FLOW WINDOWS AND FOLLOWED BY SEVERAL DAYS
OF LOW FLOWS TO ENSURE DRY CONDITIONS FOR CURING.
ss
0
ss
CONCRETE WASHOUT TO BE
LOCATED NEAR STAGING AREA (SEE
TYP. DETAIL ON SHEET WWEC.10)
THE CENTRAL PORTION OF THE WAVE STRUCTURE IN THE DRY
FROM THE RIVER RIGHT MEDIUM FLOW PLATE TO THE EDGE OF THE
BYPASS CHANNEL INCLUDING THE ISLAND.
6. ENSURE THAT NO CEMENTITIOUS MATERIAL ENTERS THE WATERWAY
DURING GROUTING OPERATIONS.
7. UPON COMPLETION OF THE CENTRAL PORTION OF THE WAVE
STRUCTURE INSTALLATION AND MIN. 3—DAY GROUT CURE TIME PER
PROJECT SPECIFICATIONS, COMPLETE FINAL GRADING AND REMOVE
ALL EQUIPMENT AND FINALLY THE SUMP FROM THE WORK ZONE
ALLOWING IT TO BACKWATER.
8. REMOVE 3 OF THE 4 WALLS OF THE SUPER SACK COFFER DAM
AND ALL MATERIALS FROM THE RIVER. THE DOWNSTREAM SUPER
SACK WALL WILL REMAIN AND BE USED LATER DURING REMOVAL
OF THE TEMPORARY LOW WATER ACCESS ROAD. RECONFIGURE
SUPER SACK COFFER DAM TO INSTALL THE RIVER LEFT PORTION
OF WAVE FEATURE. REFER TO NEXT SHEET.
0
0
0
0
i
-n
0
0
T
0
0
SUPER SACK COFFERDAM
(SEE TYP. DETAIL ON
SHEET WWEC.9)
orietaPpfp.e,
MrS0001339,95;�wC'1.°
SUMP (SEE TYP. DETAIL
ON SHEET WWEC.10)
INLET PROTECTION
(SEE TYP. DETAIL ON
SHEET WWEC.9)
0)
Mo
PHASE 3 LIMITS OF
WORK x ACRES
TEMPORARY LOW-WATER STREAM CROSSING
CONSTRUCTED OVER EXISTING RAILROAD
PIERS. SEE DETAIL ON SHEET WWEC.10 FROM
NORTH CAROLINA DEQ EROSION AND
SEDIMENT CONTROL PLANNING AND DESIGN
MANUAL (CHAPTER 6).
i
ow
ow
Ow:
Q
ot)
ss
OW
a" S20 LI
REINVENTING WHITEWATER
S20 Design and Engineering
Scott Shipley, P.E.
318 Mcconnell Drive
Lyons CO, 80540,
USA
[phone]
Client:
Town of Woodfin, NC
Project Name:
Woodfin Wave at Riverside Park
Status:
Erosion Control/Water
Control/Construction Sequence
Drawings for Permitting
Drawing Name:
Wave Construction Sequence 2
Revisions:
0
Drawn By:
Riley Adams
Checked By:
Scott Shipley
Date:
October 10, 2022
Status:
Issued For Permitting
Stamp:
NOT FOR CONSTRUCTION
Sheet:
WWEC.3

CD
0
0
z
0
U
z
0
55
O
Lu
U
Z
Z
LL
0
0
O
II
II
EGOS O\ CO\TOOL SEQUE\CE
PHASE 4
PROCEED AS FOLLOWS:
1. INSTALL COFFERDAM FOR WATER CONTROL SURROUNDING RIVER LEFT WORK ZONE
USING SUPER SACK CONSTRUCTION DETAIL PROVIDED IN WHITEWATER PLAN SET.
SUPER SACKS TO BE FILLED WITH GRAVEL OR SMALL COBBLE BASED ON
CONTRACTOR PREFERENCE.
2. EXTEND LOW WATER ACCESS TO RIVER LEFT WORK ZONE IN THE WET UTILIZING
CULVERTS BETWEEN ABANDONED RAILROAD BRIDGE PIERS TO BUILD TEMPORARY
ROAD.
3. ALLOW WATER WITHIN ENCLOSED WORK AREA TO SETTLE PRIOR TO PRELIMINARY
PUMP DOWN OF WORK AREA.
4. INSTALL SUMP IN LOW CORNER OF CLOSED OFF WORK ZONE AND INSTALL INLET
PROTECTION MEASURES SHOWN IN WHITEWATER PLAN SET DETAILS. INSTALL
ADDITIONAL MEASURES SUCH AS SILT FENCE AND/OR SETTLING PONDS IN
DESIGNATED UPLAND AREA.
5. ONCE WATER CONTROL AND EROSION CONTROL MEASURES ARE IN PLACE AND
FUNCTIONING PROPERLY, COMPLETE CONSTRUCTION OF THE BYPASS CHANNEL IN
THE DRY FROM THE ISLAND TO THE TOP OF RIVER LEFT BANK INCLUDING
BOULDER TERRACING AND BANK STABILIZATION DOWNSTREAM OF BYPASS.
6. ENSURE THAT NO CEMENTITIOUS MATERIAL ENTERS THE WATERWAY DURING
GROUTING OPERATIONS FOR THE BYPASS STRUCTURE.
7. UPON COMPLETION OF THE RIVER LEFT PORTION OF THE WAVE STRUCTURE
INSTALLATION AND MIN. 3—DAY GROUT CURE TIME PER PROJECT SPECIFICATIONS,
COMPLETE FINAL CHANNEL GRADING. RESTORE LEFT BANK TO PRE —CONSTRUCTION
CONDITION. SEED AND STAKE EROSION CONTROL BLANKETS ON DISTURBED SLOPES
PER DETAILS IN WHITEWATER PLAN SET. REMOVE ALL EQUIPMENT AND FINALLY
THE SUMP FROM THE WORK ZONE ALLOWING IT TO BACKWATER.
8. REMOVE/RECONFIGURE SUPER SACK COFFER DAM FOR THE FIRST PHASE OF
TEMPORARY LOW WATER ACCESS ROAD REMOVAL.
NOTE 1: THESE PLANS ILLUSTRATE THE SUGGESTED WATER
CONTROL AND CONSTRUCTION PHASING TO COMPLETE TFIE
IN -STREAM WORK SCOPE. ANY DEVIATION FROM THESE PLANS
REQUESTED BY THE CONTRACTOR MUST BE SUBMITTED TO THE
ENGINEER FOR APPROVAL BY PERMITTING AGENCIES.
NOTE 2: THE WEATHER FORECAST SHOULD BE MONITORED \
CLOSELY PRIOR TO AND DURING ALL IN -STREAM WORK. IT IS
ESSENTIAL THAT CONCRETE PLACEMENTS BE COMPLETED
DURING LOW FLOW WINDOWS AND FOLLOWED BY SEVERAL DAYS
OF LOW FLOWS TO ENSURE DRY CONDITIONS FOR CURING. o
ss
SS -
r ^,
l Q•°w s
CONCRETE WASHOUT TO
BE LOCATED NEAR
STAGING AREA (SEE TYP.
DETAIL ON SHEET WWEC.9)
-n
0
0
O
,i
0
0
SUPER SACK COFFERDAM
(SEE TYP. DETAIL ON
SHEET WWEC.9)
SUPER SACK COFFERDAM FROM
CENTRAL CONSTRUCTION ZONE
PARTIALLY LEFT IN PLACE FOR
TEMPORARY ROAD REMOVAL.
..047,,,i. -::::%:::::::‘,:..c.i:1,:::'N' .::::::::q. ''.
,%.,e,4:47?,`::..44:ei 741,1::,..%.,:e.,:4
.�i" '•�Qi+�S p �
14 �', ice a.''.. b
:: . '.% :co ,-, . J
1?":6".?. 70111;;":•:';
-- / //
- / 1
/ /
1
i
FOG
FOC -
FOG
SS
do
Foc
0)
7
I
•;.0,7:16:
`1:::0 •
.
.:
:,;,
..S70 :20 AfP'i
,;.:4101,.
SS —
Mo
SS.
MO
FOC
SS —
PUMP PLATFORM & DISCHARGE
HOSE. SEE DETAILS & NOTES
SUMP (SEE TYP. DETAIL
ON SHEET WWEC.10)
INLET PROTECTION
(SEE TYP. DETAIL ON
SHEET WWEC.9)
TEMPORARY LOW-WATER STREAM CROSSING
CONSTRUCTED OVER EXISTING RAILROAD
PIERS. SEE DETAIL ON SHEET WWEC.10 FROM
NORTH CAROLINA DEQ EROSION AND
SEDIMENT CONTROL PLANNING AND DESIGN
MANUAL (CHAPTER 6).
Oc
o —. Ow
i
i
O'v"v
35.
SS
FOC
OVV
FOC
00
SS
FOC
OW —
a" S20 LI
REINVENTING WHITEWATER
S20 Design and Engineering
Scott Shipley, P.E.
318 Mcconnell Drive
Lyons CO, 80540,
USA
[phone]
i
Client:
Town of Woodfin, NC
Project Name:
Woodfin Wave at Riverside Park
Status:
Erosion Control/Water
Control/Construction Sequence
Drawings for Permitting
Drawing Name:
Wave Construction Sequence 4
Revisions:
0
Drawn By:
Riley Adams
Checked By:
Scott Shipley
Date:
October 10, 2022
Status:
Issued For Permitting
Stamp:
NOT FOR CONSTRUCTION
Scale:
1"=40'
Sheet:
WWEC.4

POST -CONSTRUCTION PERIODIC INSPECTION CHECKLIST
This checklist is intended to be completed by the design engineer as part of a periodic post -
construction inspection of the in -stream scope designed by S20 Design & Engineering. All project
components designed by others are not included as part of this inspection. In the event maintenance
items are identified, a plan will be developed with the Town of Woodfin in cooperation with the
Department of the Army (if required) to determine appropriate remedial actions to restore the
project to an approved design configuration.
Project: Woodfin Wave at Riverside Park
Design Engineer Representative:
Client Representative:
Date Completed:
Inspection Item Remedial Action Required
E Wave Structure Integrity Engineer to Review Items of Concern & Propose Action
(Check for Damaged Grout, Displaced Boulders, Erosion)
E Mid -Stream Island Integrity
(Check for Damaged Grout, Displaced Boulders, Erosion)
Engineer to Review Items of Concern & Propose Action
❑ Bypass Structure Integrity
(Check for Damaged Grout, Displaced Boulders, Erosion)
Engineer to Review Items of Concern & Propose Action
E Wave Structure Scour Pad Elevation Install Additional Riprap Armoring to Achieve Design
(Current Grade within I2" of Design Grade)
Grade (Engineer to Review Sizing)
E Bypass Structure Scour Pad Elevation Install Additional Riprap Armoring to Achieve Design
(Current Grade within I2" of Design Grade)
Grade (Engineer to Review Sizing)
❑ Concrete Approach Pad Integrity Patch Concrete, Engineer to Review Other Specific Items
(Check for Spalled Concrete, Exposed Hazards)
of Concern and Propose Action
❑ Put -In Area
(Check for Displaced Boulders, Erosion)
Reset Boulders if Necessary. Engineer to Review Other
Specific Items of Concern and Propose Action
E Take-out Beach & Access Stairs Reset Boulders if Necessary. Design Engineer to Review
(Check for Damaged Grout, Displaced Boulders, Erosion)
Other Specific Items of Concern and Propose Action
❑ River Left Bank Protection
(Check for Displaced Boulders, Erosion)
Reset Boulders if Necessary, Replace and/or Re -stake
Fabric Downstream of Bypass, Design Engineer to
Determine if Additional Remedial Action is Necessary.
❑ River Right Bank Protection Reset Boulders if Necessary, Design Engineer to
(Check for Displaced Boulders, Erosion)
Determine if Additional Remedial Action is Necessary.
❑ Feature Boulder Clusters
(Check for Displaced Boulders)
Reset Boulders if Necessary, Remove Any Obstructions
❑ General Sediment Deposition Concerns
Remove Excess Sediment as Necessary, Design Engineer
to Review Specific Items of Concern and Propose Action
❑ General Scour/Erosion Concerns Engineer to Review Items of Concern & Propose Action
NOTES
o

Maintenance Plan for In -Stream Features
Woodfin Wave at Riverside Park — Woodfin, North Carolina
This plan has been prepared to address potential maintenance requirements associated with the Woodfin
Riverside Park in -stream scope. Typical maintenance concerns include damage to the recreation structure
or bypass, scour downstream of structures, erosion of streambanks and deposition of sediment following
flood events.
S20 has designed project components to minimize or eliminate these maintenance issues by using grout
to optimize durability of the recreation structures, installing riprap armoring and/or keying into the
shallow bedrock downstream of each recreation structure where scour risk is greatest. Bank protection
will be boulder terracing which provides erosion resistance and excellent access for park users and rescue
personnel. The river left bank downstream of the bypass will also be stabilized where bedrock is not
present utilizing buried and planted riprap fill with durable erosion control blankets to retain soil until
vegetation has been established.
The most likely maintenance required for the Town of Woodfin would be restoring any displaced boulders
from the un-grouted sections of bank protection after large flood events (i.e. the put -in area). Recreation
structures are grouted and require little to no maintenance. They are designed to flush out sediment that
may accumulate in the pools below drops, with planned deposition areas between the wave and bypass
and along the banks immediately below the wave and bypass (i.e. the take-out area).
Periodic Inspections
S20 personnel are available if requested to perform inspection of the in -stream components on an annual
or as -needed basis following completion of construction activities. On a typical project, inspection are
conducted annually each year for 3 years following completion of construction and then on an as -needed
basis after that. Inspections would involve a walkdown of the entire site with the Client and completion
of a checklist including typical maintenance items and documentation of any special conditions observed.
A sample checklist is attached for use during post -construction inspections. Inspection items would
include, but not be limited to: the wave structure, bypass, mid -channel island, scour pads/armoring,
approach pads, terraced boulder bank protection, bank repair area, put -in and take-out beaches, flow
deflectors, boulder clusters, and any general erosion or deposition problem areas identified. Inspections
would preferably be scheduled during periods of lowest flows to provide the greatest access and visibility.
S20 personnel are also available to provide technical oversight during any requested maintenance
activities.
Remedial Actions
The sample inspection checklist provided indicates which maintenance items are general repairs and
which may require additional analysis by S20 Engineering prior to resolution. Typical remedial actions
would involve installing additional scour protection (riprap armoring) in areas where it has settled
excessively or been removed, re -setting any boulders displaced from un-grouted structures during flood
1
318 McConnell Dr I Lyons I CO 180302

ra
i
events, and potentially sediment removal from isolated areas. S20 would provide the Client with a copy
of the completed Inspection Checklist as part of a memo including site photographs and notes to
document any items that required additional analysis prior to recommending remedial actions.
Budgetary Considerations
S20 recommends setting aside 1%-2% of construction costs per year for maintenance of in -stream
structures until a "maintenance fund" is built up. This is intended to cover larger 10-20yr flood events
which may require aesthetic maintenance or functional maintenance, such as sediment deposition on
pathways or at access points. The whitewater structures are designed to withstand a 100-yr flood event
and self -clean, flushing out sediment below the drops, so maintenance required will be primarily
aesthetic, not structural, and can be done at the discretion of the Town.
Additionally, S20 typically recommends setting aside a 10% contingency fund in the event that any tuning
of the structures is requested after construction. In some cases, after whitewater features have been in
place for a season or two, a client may wish to make minor adjustments based on user experiences and
feedback. S20 then has the ability to go back in and make the wave feature more or less powerful and
perform other minor modifications to customize the wave. This is not required, but it is an option that
provides flexibility to the Client. The design of the Woodfin Wave includes channel inserts in the low flow
notch of the wave feature to allow even more flexibility in tuning the wave, and the concrete approach
pads provide a means to control water more easily during any tuning activities.
2
318 McConnell Dr I Lyons I CO 180302