The document summarizes a student project to design a field-scale research facility to study the impacts of sea level rise on freshwater bottomland hardwood forests. The students proposed two site options for the facility and selected rice fields based on criteria like hydrology and existing infrastructure. Their design for the rice field site includes upgrading berms, installing a water control structure and pump, and developing plans to manipulate water levels and simulate tidal influences to study vegetation, soil, and hydrologic responses under rising sea levels. The student team collaborated to complete modeling, drawings, cost estimates, and recommendations to help implement the designed facility.

1. Development of a Field-Scale Research Facility to Assess the
Effects of Sea Level Rise on Freshwater
Bottomland Hardwood Forests
Hudson Adams, Riley Garvey, Alyssa Knight, Rachel Mordovancey,
Mattie Rourk, Alexa Schiazza
Clemson University, Clemson, SC
October 20, 2020

2. Outline
● Introduction
○ Background
○ Rationale
○ Objective(s)
○ Approaches
● Literature Review
● Materials and Methods
● Results
● Recommendations
● Acknowledgements

3. Introduction

4. Background
Role of Wetlands
● Wetlands provide many important ecosystem services
○ Improving and protecting water quality
○ Providing fish and wildlife habitats
○ Storing floodwater
● Wetlands are some of the most productive ecosystems
● The overall global wetland value was estimated to be around
47.4 trillion dollars per year

5. Background
Climate Impact on Wetlands
● Climate change, and the resulting sea level rise, affect the health and
functionality of tidal wetlands.
● Sea level rise causes the inundation and potential displacement of these
areas.
● Such stressors may disassemble the existing ecosystem of the wetland due
to loss of vegetation, loss of habitat, and biogeochemical changes in the soil.
● Wetlands offer valuable ecosystem services such as erosion control,
bioremediation, and flood protection.
● It is important to be able to predict how these services and ecosystems will
be impacted as sea levels rise.

6. Background
Wetland Maps

7. Background
Project Scope
● Freshwater tidal wetlands are wetlands that are influenced by the tides but
do not suffer from saltwater intrusion.
● In the lowlands of South Carolina these are both common and more distant
from the coastline than expected in other areas due to the extremely
gradual elevation changes.
● There are two types of freshwater tidal wetlands, marsh and forest, with
the differences occurring due to the hydroperiod, or the period of time the
wetland is covered by water.
● Ecosystem services can be negatively impacted by environmental/climate
change, therefore it is important to monitor these changes.

8. Background
Facility Location
● Located in the Santee
Experimental Forest on
the East Branch of the
Cooper River
● Sites are bottomland
hardwood forest

9. Rationale
● Between a field and a lab facility, a field research facility is needed
because wetlands are so complex that if meaningful data is to be
collected, all of the biogeochemical features would need to be
incorporated into a lab research facility. Thus, a field facility is best in
order to more easily bring together those complex ecosystem functions.
● Wetlands provide many ecosystem services such as improving water
quality and storing flood water. If rising sea level affects the way they
currently function, then they may lose some of these services.
● The models currently used to predict how ecosystem services will be
affected are not useful, as freshwater tidal wetlands have not been
adequately studied.
● The idea for this project is to create a mesocosm to gain critical data by
which to base future models on.

10. Hypothesis to be tested through the use of the
designed facility:
As sea level rises and
hydroperiods change, these
wetlands will shift in type and
previously nontidal wetlands will
become tidally influenced.

11. Objectives
Mission
The main objective of this project is to design and model a field scale
research facility to study the impact of climate change on the ecosystem
services provided by wetlands, in particular, to determine the effects of sea
level rise on the hydrologic regime of a freshwater tidal wetland.
Specific Objectives
1. To design impoundment/control water structures and drainage
2. To develop an operational plan
3. To develop a site plan for research site

12. Client Deliverables
1. Hydrogeomorphic Assessment – this is an integrated assessment of the land
resource data providing a basis for the site selection
a. A detailed analysis of the natural and man-made subcatchments within the
floodplain that could be the mesocosms. This analysis will focus on utilizing
the lidar data to delineate drainage areas and flow paths within the
floodplain.
b. This analysis will consider the current flow paths and hydrologic regimes.
2. Summary on the expected impacts of sea-level rise on the current hydrologic
regime
3. Facility Operational Plan
4. Site Plan

13. Approaches
Task 1
To determine
a site location
Task 2
To design the
facility

14. Task 1: To determine a site location
Sub-Tasks:
● To collect hydrological, Lidar, climate, and GIS data for the possible sites.
● To assess references, data, and similar project designs.
● To research sea-level rise modelling done by NOAA or another agency in the
Charleston area.
● To explore water containment and management methods for both options.
● To determine biodiversity of local flora within each option.
● To identify size requirements and necessary site boundaries for both
options.
● To choose an alternative to move forward into design.

15. Approaches
Site Option 1: Tidally Influenced Sub-Catchment Channel
● Put a weir in “Channel A” to divert
water to “Channel B”
● Put berm at tidally influenced
intersection of “Channel B”
● Use main channel water to flood
“Channel B” area
Site Plan Site Map

16. Approaches
Site Option 1: Tidally Influenced
Sub-Catchment Channel
A B C
C
A
B

17. Approaches
Site Option 2: Non-Tidal Controlled Rice Fields
● Retrofit existing berms in rice field
plot
● Install a pump from Nicholson
Creek to the chosen rice field plot
● Construct a weir on the opposite
site of the rice field to let water
escape when necessary
Site Plan Site Map

18. Approaches
Site Option 2: Non-Tidal
Controlled Rice Fields
A B C
C
A
B

19. Task 2: To design a facility
Sub-Tasks:
● To evaluate site planning considerations including site access, elevation, and wetland
impact.
● To examine possible methods of passive flow/filling.
● To identify needs to maintain a healthy ecosystem such as water retention rate.
● To determine what additional infrastructure such as water control structures, pipe
networks, pumps, and drainage systems will be required.
● To model hydrologic regimes and design plans by utilizing CAD, HEC-RAS, and SOLIDWORKS.
● To create a design plan draft.
● To develop a final site plan.
● To formulate a facility operations plan by determining how the water control system will
run.
● To assess the cost of the designed field research facility.

20. Pre-/post-development
modeling and structural
drawings
Developing tidal
regime and
operational plans
CAD site
development
and plan set
Task Management
Team
We collaborated as a group on all aspects
of the project. To ensure that everything
got done, each group member was
assigned a different task to be in charge
of:
● Hudson Adams
○ Structural Drawings using
SolidWorks
● Riley Garvey
○ Pre-development modeling
using Hecras*
● Mattie Rourk
○ Post-development modeling
○ Paper Format
● Alyssa Knight
○ Developing tidal regime
○ Operational Plans
● Rachel Mordavancy
○ Site development using CAD
● Alexa Schiazza
○ Plan Set

21. Ecology Climate
Science
Engineering
TFW research
center
Maximizing use
of existing
infrastructure
Efficiently
capturing and
manipulating
water flows
Diverse
assemblage of
endemic
species

22. Literature
Review

23. Literature Review
Site Hydrology
● Most of the soils have high surface runoff and low infiltration
rates.
● Average annual rainfall: 1370 mm
● The peak discharges for the Turkey Creek watershed:
○ 12.0 m3
/s--2 year return period
○ 22.9 m3
/s--5 year return period
○ 31.5 m3
/s--10 year return period
○ 42.9 m3
/s--25 year return period
○ 53.2 m3
/s--50 year return period
○ 64.2 m3
/s--100 year return period
● Vegetation: pine-hardwood forests.

24. Literature Review
Parameters
● Going forward with the design, the research parameters that the facility will be used
for are:
○ Vegetation response
■ which will monitor changes in vegetation structure, composition, and
productivity including photosynthesis and transpiration
○ Soil response
■ which will monitor changes in soil biogeochemistry such as redox
conditions, greenhouse gas emissions, carbon storage, nutrient cycling,
also soil microbiology
○ Hydrologic response
■ which will monitor changes in hydrology and water quality

25. Literature Review
Turkey Creek Water Table Data
We will use Turkey Creek
data in order to estimate
Nicholson Creek flows off a
relative size comparison
since they are both type 3
streams

26. Literature Review
Sea Level Rise
How high should the water be
raised?
● The relative sea-level rise trend
in Charleston, SC is about 3.32
mm/year based on monthly
mean sea level data spanning
from 1901 to 2019.
● This was determined to be the
equivalent to a 1.09 ft sea level
rise over the span of 100 years.

27. Literature Review
Sea Level Rise

28. Literature Review
Mesocosm vs. Large-Scale Experiment
Large Scale Experiment:
● Displayed an increase in
temperature over time.
● An increase in dissolved oxygen
over time.
● Larger scale experiments are
harder to control.
Mesocosm Experiment:
● Became colonized by macrophytes
which caused shading.
○ Lower temperature over time.
● Mesocosms are often more
optimal as they are more
replicable and repeatable.
Both:
● Retain nutrients.
● Showed an increase in pH.

29. Literature Review
Mesocosm vs. Large-Scale Experiment
How does the complexity of these
two set-ups compare?

30. Materials
and
Methods

31. Materials and Methods
Modeling
● To create location and watershed basin maps of the site using ArcGIS
● To measure site hydrologic features, specifically raised water levels, using HEC-RAS
● For site design and plan set development will be created using AutoCAD Civil3D
● To design and model hydraulic structures, such as a weir structure, using SolidWorks

32. Materials and Methods
Site Needs
● Existing Conditions Evaluation
● Grading Needs (Fill Soils)
● Pump
● Hydraulic Structure: Weir
● Site Access Stair
● Electrical Instrumentation (Beyond Scope of Design)

33. Results

34. Results
Site Selection
Rice FieldChannel

35. Results
Pre-Development Flow Model Utilizing HEC-RAS
● 1-year rain event
● Rice fields are naturally
flooded from large storm
events
○ after 3 hours of this
storm, the average water
depth on the site was 22
cm
● Berms are partially inundated
- creating the need for
increased height and proper
grading

36. Results
Site Layout
Utilizing AutoCAD

37. Results
Existing Berm Conditions Utilizing AutoCAD

38. Results
Post-Development Flow Model Utilizing HEC-RAS
● 1-year rain event
● Rice fields are naturally
flooded from large storm
events

39. Results
Berm Grading Utilizing AutoCAD
● Due to the deteriorated
condition of the berms,
reinforcement and a raised
height is required.
● Berms will be 3’ top width
with a 3:1 slope down to
the existing grade.

40. Results
Spillway Grading Utilizing AutoCAD
● The spillway is be
designed to retain
the low tide tide
water level while
the hydraulic weir
will hold the high
tide.
● 3:1 slope down
from berms and
2% down the
spillway through
the berms

41. Results
Pump Station Location
● Because the site is
located in the
Nicholson Creek
flood plain, the pump
cannot be placed
within the wetland
area.
● The station will be
located off of
Summerhouse Road
adjacent to Nicholson
Creek

42. Results
Pump Station Site
Grading Utilizing AutoCAD
● The road grade will be extended by
15’ to provide a 15’ ⨯ 15’ flat surface
in order to place the pump station.
● Graded to the existing ground at 3:1
slope

43. Results
Pipe Alignment Utilizing AutoCAD
● Carbon coated HDPE
pipe will be utilized to
pump water from
Nicholson Creek to the
rice field plot.

44. Results
Pipe Alignment Profile Utilizing AutoCAD
● In order to avoid the
ecological impact of
burying the pipe, it will
be run over the ground
on stilts supported by
pylons
● Because of the warm
climate of Huger, SC,
temperature related
deflections of the pipe
are of minimal concern.

45. Results
Pipe Support
● The pylons will be
supported with
compacted fill
material.
● At every turn in the
pipe, an earthen
berm will be placed
to support the bend.

46. Results
Hydraulic Design Utilizing SolidWorks
● Design includes a gate on the
weir that is operated by a rack
and pinion system powered by
a small motor
● The gate will be operated on a
time schedule to simulate the
coming and going of the tide
each day

47. Results
Rack and Pinion System
● Pros: Easy to design and
maintain
● Cons: If the rack is misaligned it
may damage the entire gear
box, Can be inaccurate if a
higher quality is not bought
and maintained but this is not
an issue for this project.

48. Results
Cost Assessment-Labor
Team Member: Hudson
Task Hours
Meetings
-------
PowerPoint
Solidworks
Total
Team Member: Riley
Task Hours
Meetings
PowerPoint
HEC-RAS
Total

49. Results
Cost Assessment-Labor
Team Member: Alyssa
Task Hours
Meetings
-------
Statistics
HEC-RAS
Total
Team Member: Rachel
Task Hours
Meetings
--------
PowerPoint
AutoCAD
Total

50. Results
Cost Assessment-Labor
Team Member: Mattie
Task Hours
Meetings
--------
PowerPoint
HEC-RAS
Paper
Total
Team Member: Alexa
Task Hours
Meetings
----------
PowerPoint
HEC-RAS
Paper
Total

51. Results
Cost Assessment-Hydraulic Design

52. Results
Cost Assessment-Grading

53. Results
Cost Assessment-Pump

54. Recommendations

55. Recommendations
● We recommend implementing site option 2 - non-tidal
controlled rice fields for the research facility, based on the
criteria outlined in the results section as well as field
observations
● Moving forward, we will provide more detailed
recommendations for developing the facility on this site

56. Ecology Climate
Science
Engineering
TFW research
center

57. Acknowledgements
Sincerely,
Alexa, Alyssa, Hudson, Mattie,
Rachel, and Riley
Dr. Darnault,
Thank you for guiding us throughout this
project and giving us helpful feedback
on our presentation and paper.
Dr. Xiao,
Thank you for your help throughout the
project process and giving us helpful
feedback about our powerpoint.
Dr. Trettin,
Thank you for giving us the opportunity to
work alongside you to develop a field-scale
research facility to observe the effects
global warming, specifically sea level rise,
has on bottomland hardwood forests. We
hope this project helps you and the USDA
Forestry service devise a plan to
implement in the future.
Julie,
Thank you for showing us around both the
tidally influenced sub-catchment channel,
and the non-tidal controlled rice fields.
This site visit was extremely helpful in the
completion of our project design.

58. Thank You!