Charles Creek Flood Mitig Plan- 2018

NC
CITY OF ELIZABETH CITY
CHARLES CREEK FLOOD MITIGATION PLAN
FINAL

CHARLES CREEK FLOOD MITIGATION PLAN
FINAL

Prepared for:
City of Elizabeth City

Prepared by:
Moffatt & Nichol
4700 Falls of Neuse, Suite 300
Raleigh, NC 27609
919-781-4626

March, 2018

This plan was prepared by the City of Elizabeth City under grant award # NA15NOS4190091 to the
Department of Environmental Quality, Division of Coastal Management from the Office for Coastal
Management, National Oceanic and Atmospheric Administration. The statements, findings, conclusions,
and recommendations are those of the author(s) and do not necessarily reflect the views of DEQ, OCM,
or NOAA.

1

TABLE OF CONTENTS
Executive Summary ....................................................................................................................................... 5
1 Project Background ............................................................................................................................... 6
2 Available Data Collection ...................................................................................................................... 8
2.1 Tides/Water Levels ....................................................................................................................... 8
2.2 Precipitation .................................................................................................................................. 9
2.3 Stormwater Infrastructure .......................................................................................................... 10
2.4 FEMA Models .............................................................................................................................. 11
2.5 Previous Studies and Reports ..................................................................................................... 13
3 Existing Watershed Conditions ........................................................................................................... 14
3.1 Topography ................................................................................................................................. 14
3.2 Land Use ...................................................................................................................................... 15
3.3 Soils ............................................................................................................................................. 17
3.4 Drainage Patterns ....................................................................................................................... 18
4 XPSWMM Modeling of Existing Conditions ........................................................................................ 19
4.1 Model Setup ................................................................................................................................ 19
4.2 Water Level Boundary Conditions .............................................................................................. 20
4.3 Rainfall/Tide Combinations ......................................................................................................... 22
4.4 Calibration and Model Sensitivity ............................................................................................... 22
4.5 Existing Conditions Model Results .............................................................................................. 22
5 Flood Mitigation Options to Improve Resilience ................................................................................ 24
5.1 Investigated Alternatives ............................................................................................................ 24
5.2 Multifunction Protective Berms .................................................................................................. 25
5.2.1 Model Setup ........................................................................................................................ 25
5.2.2 Model Results and Level of Protection Achieved ............................................................... 26
5.3 Flood Gate and Pump System ..................................................................................................... 28
5.3.1 Model Setup ........................................................................................................................ 28
5.3.2 Model Results and Level of Protection Achieved ............................................................... 28
5.4 Green Infrastructure ................................................................................................................... 30
5.4.1 Model Setup and Results .................................................................................................... 30

2

5.5 Non-Infrastructure Alternatives .................................................................................................. 31
5.5.1 Elevate Structures ............................................................................................................... 31
5.5.2 Relocate Structures ............................................................................................................. 31
5.5.3 Buyout and Demolition ....................................................................................................... 31
5.6 Stormwater and Floodplain Ordinance Revisions ....................................................................... 31
5.6.1 Stormwater Ordinance........................................................................................................ 31
5.6.2 Floods: Chapter 154 Code of Ordinances ........................................................................... 32
5.6.3 Additional Resources for Ordinance Revisions ................................................................... 32
5.7 Permitting Considerations for Flood Mitigation Options ........................................................... 33
5.8 Opinions of Probable Costs for Flood Mitigation Alternatives ................................................... 34
5.9 Estimated Flood Reduction Benefits for Flood Mitigation Alternatives ..................................... 34
6 Funding Approaches ........................................................................................................................... 35
6.1 Federal Emergency Management Agency (FEMA) Programs ..................................................... 35
6.1.1 Hazard Mitigation Grant Program (HMGP) ......................................................................... 36
6.1.2 Pre-Disaster Mitigation (PDM) Program ............................................................................. 36
6.1.3 Flood Mitigation Assistance (FMA) Program ...................................................................... 36
6.2 US Department of Housing and Urban Development (HUD) Community Development Block
Grant Disaster Recovery (CDBG-DR) Program ........................................................................................ 36
6.3 Clean Water Management Trust Fund (CWMTF) Grants ............................................................ 36
6.4 NC Department of Environmental Quality (NCDEQ) Water Resources Development Grant
Program................................................................................................................................................... 37
6.5 National Oceanic and Atmospheric Administration Coastal Resilience Grants Program ........... 37
6.6 Environmental Protection Agency (EPA) Urban Waters Small Grant Program .......................... 37
6.7 EPA Section 205(j) Grant Program .............................................................................................. 38
6.8 National Fish and Wildlife Foundation (NFWF) Five Star and Urban Waters Restoration Grant
Program................................................................................................................................................... 38
6.9 Clean Water State Revolving Fund (CWSRF) ............................................................................... 38
7 Preliminary Plan Recommendations ................................................................................................... 39
8 References .......................................................................................................................................... 40
Appendix A. Tide Exceedance Analysis and Rainfall Record ................................................................... 41
Appendix B. Affected Properties During Storm Events ........................................................................... 44
Appendix C. Public Involvement and Engagement ................................................................................. 54
Appendix D. Post-Flood Recovery Strategies to Improve Resilience ...................................................... 56

3

Appendix E. Charles Creek Flooding Photos ........................................................................................... 58
Appendix F. Permit Scoping Meeting Minutes ....................................................................................... 60

LIST OF FIGURES
Figure 1-1. Flooding near Charles Creek (City of Elizabeth City, 2017)......................................................... 6
Figure 1-2. Charles Creek study area ............................................................................................................ 7
Figure 2-1. Gage at Elizabeth City Mariners Wharf Park in the Pasquotank River (North Carolina
Floodplain Mapping Program, 2017) ............................................................................................................ 8
Figure 2-2. 2013-2017 water level record for gage at Elizabeth City Mariners Wharf Park (North Carolina
Floodplain Mapping Program, 2017) ............................................................................................................ 9
Figure 2-3. Stormwater infrastructure surrounding Charles Creek ............................................................ 10
Figure 2-4. FRIS flood risk zone map for Charles Creek and Elizabeth City (North Carolina Floodplain
Mapping Program, 2017) ............................................................................................................................ 11
Figure 2-5. FIMAN flood scenario, 3 ft.-NAVD water elevation (North Carolina Floodplain Mapping
Program, 2017) ........................................................................................................................................... 12
Figure 2-6. FIMAN flood scenario, 5 ft.-NAVD water elevation (North Carolina Floodplain Mapping
Program, 2017) ........................................................................................................................................... 13
Figure 3-1. Charles Creek area topography ................................................................................................ 14
Figure 3-2. USGS StreamStats watershed delineation – Charles Creek at its confluence with the
Pasquotank River (USGS, 2018) .................................................................................................................. 15
Figure 3-3. Charles Creek area land use ...................................................................................................... 16
Figure 3-4. Charles Creek area soil hydrologic groups ................................................................................ 17
Figure 3-5. Charles Creek area drainage system ......................................................................................... 18
Figure 4-1. Water level variation during an example wind tide event in Elizabeth City............................. 20
Figure 4-2. 10-yr flood elevation exceeded six times between 2013 and 2017 ......................................... 21
Figure 4-3. Maximum flood depth results for existing conditions – 10-yr rainfall, 1 ft.-NAVD tide level
(exceeded more than 20 times in 5 years (2013-2017)) ............................................................................. 23
Figure 4-4. Maximum flood depth results for existing conditions – 10-yr rainfall, 1.8 ft.-NAVD tide level
(10-yr surge – exceeded 6 times in 5 years (2013-2017))........................................................................... 23
Figure 4-5. Maximum flood depth results for existing conditions – 25-yr rainfall, 1 ft.-NAVD tide level .. 23
Figure 4-6. Maximum flood depth results for existing conditions – 25-yr rainfall, 3.0 ft.-NAVD tide level
(25-yr surge) ................................................................................................................................................ 23
Figure 4-7. Maximum flood depth results for existing conditions – 50-yr rainfall, 1 ft.-NAVD tide level .. 24
Figure 4-8. Maximum flood depth results for existing conditions – 50-yr rainfall, 3.6 ft.-NAVD tide level
(50-yr surge) ................................................................................................................................................ 24
Figure 5-1. Multifunction protective berm layout ...................................................................................... 25
Figure 5-2. Example vegetated protective berms ....................................................................................... 26
Figure 5-3. Maximum flood depth results for existing conditions – 25-yr rainfall, 1 ft.-NAVD tide level .. 27
Figure 5-4. Maximum flood depth results for protective berms – 25-yr rainfall, 1 ft.-NAVD tide level ..... 27

4

Figure 5-5. Maximum flood depth results for existing conditions – 50-yr rainfall, 1 ft.-NAVD tide level .. 27
Figure 5-6. Maximum flood depth results for protective berms – 50-yr rainfall, 1 ft.-NAVD tide level ..... 27
Figure 5-7. Flood gate and pump system layout ........................................................................................ 28
Figure 5-8. Maximum flood depth results for existing conditions – 25-yr rainfall, 3 ft.-NAVD tide level (25-
yr surge) ...................................................................................................................................................... 29
Figure 5-9. Maximum flood depth results for flood gate and pump system – 25-yr rainfall, 3 ft.-NAVD
tide level (25-yr surge) ................................................................................................................................ 29
Figure 5-10. Maximum flood depth results for existing conditions – 50-yr rainfall, 3.6 ft.-NAVD tide level
(50-yr surge) ................................................................................................................................................ 29
Figure 5-11. Maximum flood depth results for flood gate and pump system – 50-yr rainfall, 3.6 ft.-NAVD
tide level (50-yr surge) ................................................................................................................................ 29
Figure 5-12. Example green infrastructure concepts.................................................................................. 30
Figure A-1. Percent exceedance of water level at Mariners Wharf Park Pasquotank River gage .............. 41
Figure A-2. Percent exceedance of water level above 0 ft.-NAVD at Mariners Wharf Park Pasquotank
River gage .................................................................................................................................................... 42
Figure A-3. Precipitation record at Pasquotank River gage (2013-2017) ................................................... 43
Figure B-1. Flooded structures and parcels ................................................................................................ 44
Figure C-1. Online survey question results ................................................................................................. 55
Figure C-2. Online survey question results ................................................................................................. 55

LIST OF TABLES
Table 2-1. 24-hour rainfall depths for given storm events in Elizabeth City ................................................ 9
Table 2-2. Computed flood elevations for given flood events ................................................................... 11
Table 3-1. Overland Manning’s N-Values ................................................................................................... 17
Table 3-2. Conduit Manning’s N-values ...................................................................................................... 18
Table 4-1. Modeled water level boundary conditions ................................................................................ 20
Table 4-2. Computed flood elevations for given flood events and occurrences in last 5 years (2013-2017)
.................................................................................................................................................................... 21
Table 4-3. Affected properties during various storm events ...................................................................... 24
Table 5-1. Opinions of probable costs for flood mitigation alternatives .................................................... 34
Table 5-2. FIMAN water levels and estimated damages for various storm events .................................... 34
Table 5-3. Cost-benefit analysis for flood mitigation alternatives .............................................................. 35

5

EXECUTIVE SUMMARY
The Charles Creek area of Elizabeth City is prone to flooding due to local rainfall, coastal storms, and wind
tide events. The City of Elizabeth City received a grant through North Carolina Division of Coastal
Management’s Planning and Management Grants Program to create a plan to mitigate flooding and
increase flooding resiliency. Moffatt & Nichol (M&N) was tasked with gathering public input and
developing solutions to improve flood resilience in the Charles Creek area.
In preparing this Charles Creek Flood Mitigation Plan, M&N completed an existing conditions assessment
and watershed evaluation. Hydrologic/hydraulic modeling and analysis using XPSWMM was conducted
to develop and support proposed flood mitigation alternatives. Work on these tasks was completed in
conjunction with M&N’s City of Elizabeth City’s Waterfront Master Planning effort. Throughout the design
and planning processes, meaningful public involvement in the development of flood mitigation
alternatives was sought using an online public participation survey as well as through multiple open public
meetings and preliminary plan presentations.
Potential flood mitigation options to improve resilience around Charles Creek include protective berms
and road raises, a flood gate and pump system, buyouts, elevation or relocation of structures, and the
implementation of green infrastructure. XPSWMM was selected to model the following conditions to
determine the potential effects of flood mitigation projects using engineered solutions: 1) Existing
Conditions, 2) Protective Berms, 3) Flood Gate and Pump System, and 4) Green Infrastructure. Non-
engineering solutions, such as buyouts and the elevation or relocation of flood-prone buildings, were also
evaluated. In addition to developing flood mitigation alternatives, post-flood recovery strategies to
further improve resilience in Elizabeth City were created.
Each of these investigated solutions provides increased flood protection against local rainfall and/or wind
tide surges. For these alternatives, funding approaches were explored in the form of loan and federal
grant programs. Revisions to policies and ordinances related to stormwater management and floodplain
development are to be considered as additional measures to meet flood resilience goals in Elizabeth City.
Based on the modeling efforts and the cost analysis, the elevation or relocation of flood-prone structures,
or the use of protective berms are recommended flood mitigation alternatives for further study. From a
cost-benefit standpoint, the elevation of flood-prone structures is the most cost effective (benefit-cost
ratio (B/C) of 8.0) followed by relocation (B/C = 4.3). However, the use of protective berms does offer
added neighborhood connectivity and recreational benefits and has a B/C of 2.9. The revision of existing
ordinances to promote the use of green infrastructure as well as the enforcement of specific freeboard
requirements for new and existing development would further improve flood resilience in Elizabeth City.

6

1 PROJECT BACKGROUND
Many areas within the lower portion of the Charles Creek watershed are just a few feet above sea level,
making the area prone to flooding due to local rainfall, coastal storms, and wind tide events. The City of
Elizabeth City received a grant through North Carolina Division of Coastal Management’s Planning and
Management Grants Program to create a plan to mitigate flooding and improve flood resilience. Moffatt
& Nichol (M&N) was tasked with gathering public input and developing solutions to improve resilience in
the Charles Creek area. In the past, the City has dedicated resources to reduce flooding in the upper
portion of the Charles Creek watershed. This study focuses on the development of flood mitigation
alternatives to decrease flooding in the lower portion of the watershed while integrating upstream
improvements.
Elizabeth City is comprised primarily of
medium density development with
intermittent forested and surrounding
agricultural areas. Much of the area
surrounding Charles Creek contains
low-lying residential neighborhoods
and swampy forested spaces. These
existing land uses were to be
considered in the development of
feasible flood mitigation alternatives.
In preparing this Charles Creek Flood
Mitigation Plan, Moffatt & Nichol
(M&N) was to perform an existing
conditions assessment and watershed
evaluation. Hydrologic/hydraulic modeling and analyses using XPSWMM were to be conducted to
develop and support proposed flood mitigation alternatives. Work on these tasks was to be completed
in coordination with M&N’s City of Elizabeth City’s Waterfront Master Planning effort.
Figure 1-1. Flooding near Charles Creek (City of Elizabeth City, 2017)

7

Figure 1-2. Charles Creek study area

8

2 AVAILABLE DATA COLLECTION
2.1 TIDES/WATER LEVELS
The North Carolina IFlows Program owns and maintains a gage in the Pasquotank River at Elizabeth City
Mariners Wharf Park. The location of the gage in proximity to Charles Creek is shown in Figure 2-1. The
gage was installed in April 2013 and records rainfall and water level measurements every five minutes.
The Pasquotank River is subject to wind tides, meaning that Charles Creek and the Elizabeth City
waterfront experience fluctuations in water levels due to wind conditions. Figure 2-2 provides a record
of river stage at the Mariners Wharf Park gage from 2013 to 2017. The gage was not functional from
September 2, 2016 until October 5, 2016, so data from this time period is absent from the complete stage
record. This absent data may include water levels that occurred during the early stages of Hurricane
Matthew.
Figure 2-1. Gage at Elizabeth City Mariners Wharf Park in the Pasquotank River (North Carolina Floodplain Mapping
Program, 2017)

9

2.2 PRECIPITATION
Point precipitation frequency estimates were obtained from the National Oceanic and Atmospheric
Administration (NOAA) Atlas 14 for Elizabeth City. The 24-hour precipitation depths for given return
periods are provided in Table 2-1. These rainfall depths were applied to an SCS Type III hyetograph to
create representative rainfall distributions for each storm event.
Table 2-1. 24-hour rainfall depths for given storm events in Elizabeth City
Return Period (yr) Rainfall Depth (in)
2 3.73
10 5.73
25 7.08
50 8.24
100 9.51
As mentioned in Section 2.1, the gage at Elizabeth City Mariners Wharf Park also records rainfall
measurements every five minutes. Rainfall data was compiled to create a complete record at the gage
from 2013 to 2017, which can be seen in Appendix A. The magnitude and frequency of rainfall events
recorded by the gage align with those provided by NOAA Atlas 14 data.
Figure 2-2. 2013-2017 water level record for gage at Elizabeth City Mariners Wharf Park (North Carolina Floodplain
Mapping Program, 2017)

10

2.3 STORMWATER INFRASTRUCTURE
The City of Elizabeth City maintains a GIS dataset for surveyed infrastructure within the City, including
stormwater pipes, inlet structures, junction boxes, and manholes. Data provided for these components
includes location, pipe size and material, invert elevation, and spill crest elevation. Additional pipe data
for the culverts located under Southern Avenue was provided by the North Carolina Department of
Transportation (NCDOT). In areas where survey data was not available, values were estimated from
adjacent existing infrastructure values (where available) as well as LiDAR data. Figure 2-3 shows the
presence of stormwater infrastructure within Elizabeth City.

Figure 2-3. Stormwater infrastructure surrounding Charles Creek

11

2.4 FEMA MODELS
The North Carolina Floodplain Mapping Program (NCFMP) developed a HEC-RAS model of Charles Creek
from its confluence with the Pasquotank River to approximately 0.4 miles upstream of Halstead
Boulevard. The model provides channel cross sections, bridge and culvert data, and river flow information
for various storm events. Modeled flood risk maps for the study area are accessible online through North
Carolina’s Flood Risk Information System (FRIS). See Figure 2-4 for the flood risk zone map for Charles
Creek at Elizabeth City.

Figure 2-4. FRIS flood risk zone map for Charles Creek and Elizabeth City (North Carolina Floodplain Mapping Program, 2017)

FRIS’s online mapping program provides computed flood elevations for the 10, 25, 50, 100, and 500-year
flood events. These values represent the elevation to which floodwater is expected to rise during each
respective storm event. Base flood elevations for events as large as the 100-year storm are provided in
Table 2-2.
Table 2-2. Computed flood elevations for given flood events
Return Period (yr) Flood Elevation (ft.-NAVD)
10 1.8
25 3.0
50 3.6
100 5.0

12

The North Carolina Flooding Inundation Mapping and Alert Network (FIMAN), also maintained by NCFMP,
provides an online flood scenario tool to simulate flood severity caused by certain water elevations in the
Pasquotank River. Flood extents, as well as an estimate of building damages incurred as a result of
flooding, are shown for water elevations ranging from 0.5 to 12 ft.-NAVD based on data from the gage at
Elizabeth City Mariners Wharf Park. Figure 2-5 and Figure 2-6 show sample flood scenario maps for surge
elevations of 3 ft. and 5 ft.-NAVD, respectively.

Figure 2-5. FIMAN flood scenario, 3 ft.-NAVD water elevation (North Carolina Floodplain Mapping Program, 2017)

13

Figure 2-6. FIMAN flood scenario, 5 ft.-NAVD water elevation (North Carolina Floodplain Mapping Program, 2017)
2.5 PREVIOUS STUDIES AND REPORTS
As part of previous initiatives, Elizabeth City has expended resources to study flooding and make
improvements in the upper portion of the Charles Creek watershed. In 1989, the City conducted a flood
mitigation study that examined options for constructed floodwalls and dikes along the Pasquotank River
waterfront. This study proposed a floodwall/dike system at a plan elevation of either 6 or 8 ft.-NAVD to
mitigate flooding from the River. The following flood mitigation plan focuses on potential alternatives for
further study to improve resilience and provide flood protection around Charles Creek in the lower portion
of the watershed.

14

3 EXISTING WATERSHED CONDITIONS
3.1 TOPOGRAPHY
NCFMP maintains a Quality Level 2 (QL2) LiDAR dataset for the eastern portion of the state. The QL2
LiDAR was downloaded from the NCFMP Spatial Data Download website (North Carolina Floodplain
Mapping Program, 2017). The LiDAR has been processed to screen buildings, roads, tree cover and water
points to separate levels, so they are easily excluded from ground points. The ground, road, and water
shots were used to develop the surrounding topography. Buildings were excluded from the final terrain
set and instead represented in the model as inactive areas. Bathymetry for Charles Creek was created
using channel cross sections from the HEC-RAS model of the creek maintained by NCFMP. Figure 3-1
shows the LiDAR topographic surface for the Charles Creek area.

Figure 3-1. Charles Creek area topography

15

3.2 LAND USE
The watershed area contributing to the Charles Creek at its confluence with the Pasquotank River is
approximately 3.6 square miles (Federal Emergency Management Agency, 2009). According to USGS
StreamStats’ watershed delineation tool, the contributing watershed area is roughly 6 square miles
(Figure 3-2). Differences in these two areas can likely be contributed to the fact that StreamStats
computes watershed areas based on topography alone and does not incorporate the presence of
stormwater infrastructure into its calculations. Pipe networks are present within portions of the
watershed that divert runoff flows away from Charles Creek, thereby decreasing the watershed area that
actually drains to this water body.

Figure 3-2. USGS StreamStats watershed delineation – Charles Creek at its confluence with the Pasquotank River (USGS, 2018)

16

The land use in the Charles Creek watershed is primarily residential development with intermittent
agricultural fields and forested areas. For modeling purposes, land use was broken down into six different
categories: river, agricultural/cemetery, forest, medium density development, pond, and roads (Figure
3-3). Unhatched areas in Figure 3-3 are designated as medium density development. Buildings were
represented in the model as inactive areas (further discussed in Section 4.1).

Figure 3-3. Charles Creek area land use

Manning’s N-values for overland surface flow were taken from the HEC-RAS River Analysis System
Hydraulic Reference Manual (US Army Corps of Engineers, 2016). For each of the six land uses described
above, a Manning’s N-value was assigned (Table 3-1).

17

Table 3-1. Overland Manning’s N-Values
Land Use Manning’s N
River 0.04
Agricultural/Cemetery 0.04
Forest 0.10
Medium Density Development 0.025
Pond 0.01
Roads 0.014
3.3 SOILS
Soils belonging to three of the four hydrologic soil groups are found within the study area, creating a
diversity of soil conditions throughout Elizabeth City. The most predominant soil groups present are
Groups A and B. Group A and B soils have a low to moderate runoff potential and moderate to high
infiltration rates. Figure 3-4 shows the soil group distribution in the study area.

Figure 3-4. Charles Creek area soil hydrologic groups

18

3.4 DRAINAGE PATTERNS
The drainage network within the Charles Creek study area is comprised of stormwater pipe networks,
drainage ditches, and open channels. Figure 3-5 displays the locations of ditches/open channels and pipes
in the study area. Not all channels shown in Figure 3-5 were modeled—only channels that were of
considerable size and imperative to ensuring accurate surface flow and pipe connectivity were
represented. The overall drainage patterns are toward Charles Creek and the Pasquotank River.

Figure 3-5. Charles Creek area drainage system

The conduit Manning’s N-values were derived from Open Channel Hydraulics (Chow, 1959). Table 3-2
provides the values assigned to each pipe material.
Table 3-2. Conduit Manning’s N-values
Pipe Material Manning’s N
Corrugated Metal 0.022
Concrete 0.013
HDPE 0.012
PVC 0.010
Terra Cotta 0.012

19

4 XPSWMM MODELING OF EXISTING CONDITIONS
4.1 MODEL SETUP
XPSWMM uses a combination of one-dimensional (1D) storm network calculations linked to a two-
dimensional (2D) surface to simulate depth-averaged flood flows. 2D surface flow is based on the
TUFLOW (Two-dimensional Unsteady FLOW) computational engine which solves the full 2D, depth
averaged, momentum and continuity equation for free-surface flow (XP Solutions, 2016). The existing
conditions XPSWMM model was developed to represent conditions in the Charles Creek area to date.
A 1D storm network was developed using a combination of nodes and links. Nodes represent inlets, pipe
ends, and channel confluences. Inverts were taken from available survey or LiDAR data. Links represent
pipes, culverts, and natural channels. Survey data was used to identify pipe sizes, material, Manning’s
roughness, and length. If survey was unavailable, these values were estimated from aerial photography
and LiDAR data.
2D grid cell extents were created for the entire study area to model overland flow. A grid comprised of
20-foot grid cells was drawn around the Charles Creek study area to ensure accurate flow patterns and
flood depths.
Topographical data as described in Section 3.1 was used to create a Triangular Irregular Network (TIN)
surface in XPSWMM. In certain areas where the TIN data did not capture the geometry and/or elevation
of drainage channels, fill areas and breaklines were used.
Inactive areas were added to the model to define areas were 2D flow cannot occur. Using Built
Environment data from the NCFMP Spatial Data Download website (North Carolina Floodplain Mapping
Program, 2017), inactive areas were placed at building footprints to force the 2D overland flow around
buildings.
Land use data was incorporated into the model as a 2D global data parameter. Manning’s N-values were
assigned to each respective land use category as discussed in Section 3.2.
The 1D network is linked to the 2D surface through a series of 1D / 2D boundaries which allow for flow
both to and from the 1D network across the 2D surface. Inlet nodes were linked directly to the 2D surface
using the “Link to 2D surface” option under the node attributes.
This model was created to represent the flooding that occurs as a result of both local rainfall and elevated
water levels in the Pasquotank River. Rainfall was entered as a global data parameter for a variety of
return period events with a 24-hour duration. The 2, 10, 25, 50, and 100-year return period rainfall depths
were set up within the existing conditions model. Rainfall hydrographs were applied to delineated sub
catchments, each of which was assigned a curve number and time of concentration based on topography,
land use, and soil parameters. Water level data was entered as a flow boundary in the Pasquotank River
to allow the model to portray wind tide surges occurring during storm events. Storm surges were modeled
as steady state water level boundary conditions and are further discussed in Section 4.2.

20

4.2 WATER LEVEL BOUNDARY CONDITIONS
As discussed in Sections 2.1 and 2.4, the Pasquotank River and Charles Creek experience variations in
water level due to wind tide events. In order to determine appropriate water elevations to model, an
exceedance analysis was conducted using the Pasquotank River stage record. From this analysis, a set of
water levels was chosen to represent a variety of wind tide conditions. The water levels studied using the
existing conditions model are shown in Table 4-1. Detailed figures pertaining to the exceedance analysis
are provided in Appendix A. Most wind tide events cause a rise and fall in water level over the course of
2 to 3 days (Figure 4-1). A 24-hour rainfall event could occur as the tide was rising, at its peak, or falling.
As a result, the water level boundary was conservatively modeled over the 24-hour simulation period as
a steady state condition at the peak tide level.
Table 4-1. Modeled water level boundary conditions
Tide Elevation (ft.-NAVD)
0.25
0.5
0.75
1.0
1.5
1.8 10-yr Flood Elevation
3.0 25-yr Flood Elevation
3.6 50-yr Flood Elevation
5.0 100-yr Flood Elevation

Figure 4-1. Water level variation during an example wind tide event in Elizabeth City

21

It can be noted that over the life of the Pasquotank River gage (approximately 5 years), the 10-year flood
elevation of 1.8 ft.-NAVD, shown as a red line, was exceeded six times (a few occurred during a short
duration of time) (Figure 4-2 and Table 4-2). This is an indication that given FEMA based flood elevations
can expect to be reached more often than suggested by their respective return periods.

Figure 4-2. 10-yr flood elevation exceeded six times between 2013 and 2017

Table 4-2. Computed flood elevations for given flood events and occurrences in last 5 years (2013-2017)
Return Period (yr) Flood Elevation (ft.-NAVD) # of occurrences in last 5 years
(2013-2017)
10 1.8 6
25 3.0 0
50 3.6 0
100 5.0 0

10-yr flood elevation

22

4.3 RAINFALL/TIDE COMBINATIONS
In order to study the combined flooding effects of local rainfall and elevated water levels in the
Pasquotank River, several tide conditions were modeled in conjunction with each rainfall event. The use
of smaller tide elevations (e.g. 0.5 ft.-NAVD) simulates flood behavior when a certain rainfall depth occurs
while the Pasquotank River is relatively low. Conversely, higher tide elevations (e.g. 3 ft.-NAVD) model
the flooding that may occur around Charles Creek when storms or wind tides cause the Pasquotank River
stage to be relatively high.
Particular attention was paid to the combination of each rainfall event and its coincident storm surge
elevation (e.g. 25-year rainfall depth and 25-year surge elevation). This setup simulates both components
of a given return period event, combining corresponding rainfall depths and water levels.
4.4 CALIBRATION AND MODEL SENSITIVITY
Calibration and verification of the existing conditions model was conducted using a variety of tools and
FEMA models. River flows and water surface elevations generated in XPSWMM were compared to the
results of NCFMP’s HEC-RAS model. The two models showed similar changes in water surface elevation
throughout Charles Creek for similar events. Flooding extents produced using selected water level
boundary conditions in XPSWMM were compared to flooding extents generated by FIMAN’s flood
scenario simulation tool at the same tide level. Comparable results were observed for the 10, 25, 50, and
100-year flood events, taking into consideration that the XPSWMM model simulates both surge levels and
local rainfall while FIMAN only models storm surge elevations.
4.5 EXISTING CONDITIONS MODEL RESULTS
The existing conditions model shows flooding along Charles Creek and the Pasquotank River waterfront.
Larger rainfall events produce larger flood extents in residential neighborhoods along the creek. Models
run with higher water level boundaries create more flooding near the waterfront and cause higher
maximum water elevations in Charles Creek. Flooding maps for a variety of storm events and surge
conditions are shown in Figure 4-3 through Figure 4-8. Table 4-3 provides the total number of properties
affected during the 10, 25, and 50-year storm events. A complete list and maps of affected properties
and their values (combined land and structure) are provided in Appendix B.

23

Figure 4-3. Maximum flood depth results for existing
conditions – 10-yr rainfall, 1 ft.-NAVD tide level (exceeded
more than 20 times in 5 years (2013-2017))
Figure 4-4. Maximum flood depth results for existing
conditions – 10-yr rainfall, 1.8 ft.-NAVD tide level (10-yr surge
– exceeded 6 times in 5 years (2013-2017))
Figure 4-5. Maximum flood depth results for existing
conditions – 25-yr rainfall, 1 ft.-NAVD tide level
Figure 4-6. Maximum flood depth results for existing
conditions – 25-yr rainfall, 3.0 ft.-NAVD tide level (25-yr
surge)

24

Table 4-3. Affected properties during various storm events
Storm Event Number of Affected Properties Total Property Value
10-yr rainfall, 10-yr tide level 55 $3,670,200
25-yr rainfall, 25-yr tide level 104 $6,361,100
50-yr rainfall, 50-yr tide level 140 $8,524,000
5 FLOOD MITIGATION OPTIONS TO IMPROVE RESILIENCE
5.1 INVESTIGATED ALTERNATIVES
Flooding in Charles Creek can occur as a result of large rainfall events, elevated water levels in the
Pasquotank River due to wind tides, or a combination of both occurring simultaneously. Design
alternatives were developed based on technical and environmental feasibility in order to best improve
the level of flood protection in the Charles Creek area. Constructed improvements would decrease the
extent and magnitude of inundation, thus increasing resilience in areas prone to flooding. Buyouts and
elevation or relocation of flood-prone structures were also considered as viable options to investigate.
Meaningful community involvement in the development of flood mitigation alternatives was sought using
an online public participation survey as well as through multiple open public meetings and preliminary
plan presentations held in Elizabeth City. Additional information pertaining to public involvement and
engagement is provided in Appendix C.
Figure 4-7. Maximum flood depth results for existing
conditions – 50-yr rainfall, 1 ft.-NAVD tide level
Figure 4-8. Maximum flood depth results for existing
conditions – 50-yr rainfall, 3.6 ft.-NAVD tide level (50-yr
surge)

25

5.2 MULTIFUNCTION PROTECTIVE BERMS
5.2.1 Model Setup
One flood mitigation option consists of protective berms along the Charles Creek shoreline to mitigate
river flooding. In this scenario, berms would be constructed where needed to retain water within the
river channel and prevent flooding into neighboring residential areas (Figure 5-1). Berms would be two
to four feet high (above the adjacent ground surface) and vegetated to maintain natural aesthetics in the
Charles Creek area while increasing community resilience (example berm photos provided in Figure 5-2).
Pipes and backflow preventers would be installed where necessary for interior drainage and to prevent
ponding behind berms. In areas where berms are needed to cross over roadways, raising of roadways
and bridges up to the elevation of the berms should be implemented to maintain the desired level of
protection and ensure no low spots are present through which flood waters could enter. Road raises are
especially vital along Southern Avenue and S Road Street. Protective berms could be used in combination
with a greenway or walkway along Charles Creek to improve and promote connectivity between Mid-
Atlantic Christian University, Elizabeth City State University, as well as the neighborhoods in-between.
Recreational benefits for this option should also be considered.

Figure 5-1. Multifunction protective berm layout
Protective
berms
Greenway

26

Figure 5-2. Example vegetated protective berms
5.2.2 Model Results and Level of Protection Achieved
The construction of protective berms, along with suggested road raises, reduced flooding in
neighborhoods surrounding Charles Creek. The berms are an effective means of flood protection for
storms as large as the 25-year rainfall event with a moderate wind tide surge (1 ft.-NAVD) or a wind tide
event alone up to an elevation of 3 ft.-NAVD. Providing protection above the 25-year flood with berming
is difficult due to the localized roadway and topographic elevations. During the 25-year event, flood
waters remain contained within the channel, although flooding from surrounding stormwater
infrastructure and drainage ditches still occurs. Increased flood depths as a result of installing berms can
be seen near Dawson Street. This flooding can be mitigated by increasing the size of the pipe that runs
under Dawson Street, allowing adequate drainage from surrounding ditches into Charles Creek. The
berms and road raises provide some protection during the 50-year event, but maximum flood elevations
are high enough to overtop certain areas of the berms. See Figure 5-3 through Figure 5-6 for flooding
maps. Representative results plots are shown for the existing and alternative cases where the alternatives
provide the most protection. A complete list and map of properties affected during the 25-year storm,
those for which damages are mitigated by implementing protective berms, is provided in Appendix B.

27

Figure 5-3. Maximum flood depth results for existing
conditions – 25-yr rainfall, 1 ft.-NAVD tide level
Figure 5-4. Maximum flood depth results for protective berms
– 25-yr rainfall, 1 ft.-NAVD tide level
Figure 5-5. Maximum flood depth results for existing
conditions – 50-yr rainfall, 1 ft.-NAVD tide level
Figure 5-6. Maximum flood depth results for protective berms
– 50-yr rainfall, 1 ft.-NAVD tide level

28

5.3 FLOOD GATE AND PUMP SYSTEM
5.3.1 Model Setup
To provide flood protection during elevated wind tide conditions in the Pasquotank River, a flood gate
and pump system could be implemented near Charles Creek’s confluence with the river. The flood gate,
installed immediately downstream of the Riverside/Shepard Street bridge, would prevent water from
flowing upstream as a result of storm surges. Pumps installed upstream of the gate would redirect Charles
Creek flows around the gate and allow discharge into the Pasquotank River. In order to handle large storm
flows, selected pumps would be 24 to 36 inches in size and operate at up to 50,000 gallons per minute.
Figure 5-7 shows the proposed flood gate location.

Figure 5-7. Flood gate and pump system layout
5.3.2 Model Results and Level of Protection Achieved
The implementation of a flood gate and pump system significantly reduced the extent and magnitude of
flooding in the Charles Creek area for storms as large as the 50-year rainfall event with the corresponding
50-year surge of 3.6 ft.-NAVD. The flood gate blocked storm surges from moving upstream while the
pumps maintained low water levels in the channel, allowing runoff volumes to drain effectively. Refer to
Flood gate
Pump
station

29

Figure 5-8 through Figure 5-11 for flooding maps. A complete list and map of properties affected during
the 50-year storm, those for which damages are mitigated by implementing a flood gate and pump
system, is provided in Appendix B.

Figure 5-8. Maximum flood depth results for existing
conditions – 25-yr rainfall, 3 ft.-NAVD tide level (25-yr surge)
Figure 5-9. Maximum flood depth results for flood gate and
pump system – 25-yr rainfall, 3 ft.-NAVD tide level (25-yr
surge)
Figure 5-10. Maximum flood depth results for existing
conditions – 50-yr rainfall, 3.6 ft.-NAVD tide level (50-yr
surge)
Figure 5-11. Maximum flood depth results for flood gate and
pump system – 50-yr rainfall, 3.6 ft.-NAVD tide level (50-yr
surge)

30

5.4 GREEN INFRASTRUCTURE
5.4.1 Model Setup and Results
Green infrastructure serves as a potential add-on to the above flood mitigation options in order to
improve the behavior of Elizabeth City’s existing stormwater system. The installation of green
infrastructure would decrease the percentage of land that is impervious, thereby reducing peak flows that
run off to stormwater infrastructure. XPSWMM model results show that peak runoff flows during more
severe rainfall storm events may be reduced by 5 to 10 percent by implementing green infrastructure on
a widespread scale designed to intercept the first 1.5 inches of rainfall. Soil conditions in the study area
(Section 3.3) are preferential for green infrastructure given that Group A and B soils with low runoff
potential and high infiltration rates are present around Charles Creek. One reason that the green
infrastructure was assumed to be designed to only intercept the first 1.5 inches of rainfall (versus 1.5
inches of runoff) is that some lower-lying areas within Charles Creek would likely have constraints
concerning the seasonal high water table. Figure 5-12 shows example green infrastructure concepts,
which can also be applied elsewhere throughout Elizabeth City and the Charles Creek watershed to
improve storm drainage.

Figure 5-12. Example green infrastructure concepts
Green infrastructure
and streetscape
improvements
(bioswales, rain
gardens, etc.)

31

5.5 NON-INFRASTRUCTURE ALTERNATIVES
In addition to investigating gray and green infrastructure flood mitigation alternatives, the option to
elevate, relocate, or buyout affected structures was explored. Post-flood recovery strategies to further
improve resilience were also developed and can be found in Appendix D.
5.5.1 Elevate Structures
The option to elevate affected homes and other structures was considered for each storm event. Each
structure would be elevated approximately 3 feet in order to provide a substantial increase in flood
protection. Concrete blocks would be used to raise the building foundation. A concept level cost to
elevate each structure is $15,000. The number of buildings elevated to mitigate flooding during each
storm event is provided in Table 4-3.
5.5.2 Relocate Structures
The option to relocate affected structures was evaluated based on costs to purchase affected properties
and move their respective structures. Flooded buildings would be relocated approximately one mile, with
a moving cost of about $20,000 per structure (number of structures provided in Table 4-3). Also included
in a complete cost estimate is the land purchase cost of affected properties, provided for each storm event
in Appendix B.
5.5.3 Buyout and Demolition
The buyout and demolition of affected structures was considered as an additional flood mitigation
alternative. The cost to demolish structures includes the total property buyout cost (both land and
structure), demolition cost (assumed to be approximately $10,000 per building), as well as the annual lost
tax value of razed properties. The number of structures to be demolished for flood mitigation during each
storm event is provided in Table 4-3 and the affected properties and values are listed in Appendix B.
5.6 STORMWATER AND FLOODPLAIN ORDINANCE REVISIONS
The City’s Stormwater Ordinance was adopted in November 2001, establishing base criteria for
implementing stormwater management within the City. The Floods Ordinance was adopted in 2004 and
established policies and procedures for floodplain development. A brief overview of each ordinance and
recommended modifications to mitigate flood losses and promote resilience are noted below.
5.6.1 Stormwater Ordinance
The purpose of the Stormwater Management Ordinance is to protect, maintain, and enhance the public
health and safety by establishing minimum requirements for stormwater management, including flood
control and water quality improvements. The language of the stormwater ordinance favors larger
detention facilities for managing stormwater over green infrastructure. It further discourages green
infrastructure by specifically stating that plans could be rejected if numerous small measures are
incorporated rather than fewer larger ones (Section G, Number 4).
It is recommended that the stormwater ordinance be modified to allow/promote the use of green
infrastructure for both water quantity and quality control for new development, redevelopment, and
retrofit opportunities. This may be accomplished by updating the ordinance to reflect the changes to the
State’s stormwater rules as well as NCDEQ’s new design guidance and minimum criteria, both

32

implemented in 2017. Specific green infrastructure practices should be listed in the ordinance to reinforce
the desirability of implementing these stormwater management practices such as: bioretention cells, rain
gardens, permeable pavement, sand filters, and treatment bioswales. Additionally, it is recommended
that the design criteria for storm events be simplified for consistency in development sizes. For instance,
regardless of the type and/or size of the new development, specific design requirements for stormwater
management and water quality improvement should be implemented.
5.6.2 Floods: Chapter 154 Code of Ordinances
The purpose of the Flood Ordinance is to promote public health and safety and to minimize public and
private losses due to flood conditions. The ordinance does not currently require freeboard for new
construction, meaning that the lowest level of a new structure must be some additional specified feet
above FEMA’s mapped base flood elevation. The ordinance does have a requirement for a minimum 2-
foot increase from adjacent highest grade for new structures in areas where there are no FEMA mapped
base flood elevations.
Based upon modeling efforts, it is recommended that the City implement a minimum 1.5-foot freeboard
requirement for all new development to provide resiliency and protection during tidal surges. The City
may also want to consider developing criteria to impose the freeboard requirement on existing structures
where multiple loss events have occurred.
There is precedence in the City’s coastal area for implementing such changes. For example, in 2014 the
City of Norfolk implemented a 2-foot freeboard requirement above their FEMA mapped base flood
elevations to provide resilience and to account for future sea level rises. The City of Norfolk also addressed
existing development by incorporating freeboard requirements if certain cumulative damage conditions
had been met (i.e., alteration of structural integrity, two flood events each causing 25 percent of the
market value or more of damage to the structure).
5.6.3 Additional Resources for Ordinance Revisions
Additional resources to evaluate the City’s development, stormwater, and flood management ordinances
are available through the US Environmental Protection Agency (EPA) and the Center for Watershed
Protection (CWP). The US EPA has developed a water quality scorecard resource that assists local
governments in incorporating green infrastructure practices at the municipal, neighborhood, and site
levels. The water quality scorecard is accessible from their website:
http://www.epa.gov/smartgrowth/water_scorecard.htm. The EPA also has developed a matrix of
recommended smart growth policy changes for climate adaptation and resilience. The matrix addresses
flooding and extreme weather, sea level rise, overall strategies, etc. The guidance and matrix may also be
downloaded at the EPA’s smart growth website.
The CWP provides a Better Site Design Code and Ordinances Worksheet to assist in incorporating low
impact development practices and green infrastructure for water quality and quantity control. These
resources were updated in December 2017 and are available for download from the CWP website:
www.cwp.org.

33

5.7 PERMITTING CONSIDERATIONS FOR FLOOD MITIGATION OPTIONS
As part of the assessment of the potential flood mitigation options from the City, a meeting was conducted
to inform appropriate regulatory agencies about the project and gather input on the proposed solutions.
Agencies and departments, in addition to M&N representatives, in attendance are listed below. A
complete list of meeting attendees and a summary of the meeting minutes is included in Appendix F.
 US Army Corps of Engineers (USACE)  NCDEQ Raleigh
 NC Division of Coastal Management
(NCDCM and NCDCM-Fisheries)
 NC Wildlife Resources Commission
(NCWRC)
 NC Division of Water Resources
(NCDWR)
 NC Division of Waste Management
(NCDWM)
 Albemarle-Pamlico National Estuary
Partnership - CHPP
 NC Division of Energy, Mineral, and
Land Resources (NCDEMLR)
 City of Elizabeth City – Public Works  City of Elizabeth City – Planning
 US Fish and Wildlife Service (USFWS)
Based on discussion with the agencies, the main concerns and feedback are as follows:
- Wetlands – If the protective berm option is selected for further study, a wetland delineation
should be completed along the path of the berms in order to define and quantify potentially
impacted wetland areas. All of the agencies agreed that the berms should ideally be located in
areas where flood protection can still be provided while avoiding/minimizing wetland impacts.
When impacts occur, mitigative measures will likely have to be taken to address these effects.
- Public Trust Waters – Berms located within the 30-foot buffer zone of Public Trust Waters should
be studied to ensure that they do not cause increased runoff to these waters or cause funneling
or redirection of waters to other areas increasing their flood levels.
- Fisheries – Significant concerns were raised by all agencies with the flood gate and pumps
alternative. Most concerns centered around the system’s potential detrimental effects on the
spawning and migratory behaviors of anadromous fish populations (Blueback Herring and the
Alewife) in Charles Creek, which is a designated anadromous fish spawning area with moratoria
set from Feb 15 through Jun 15 (stated by NCDCM-Fisheries). The concern with a gate structure
is that there will be pressure to operate and close the gates even during this moratoria due to
nor’easters which are prevalent during that time. NCWRC and NCDCM-Fisheries have fish
population and monitoring data, so these agencies should be consulted about providing the data
if the flood gate and pumps alternative is studied further. NCDWR and NCWRC stated that a
significant operations and maintenance plan would have to be developed for the gate closures
and pump operations so that potential effects could be accurately quantified and that significant
limits on times the system could be operated may be part of permit conditions.
- Elevate/Relocate Structures – These two flood mitigation options would likely have the lowest
permitting considerations. Residents who prefer not to relocate may potentially be open to
elevation of their homes. Additionally, relocation allows for the potential for wetland restoration
and expansion in flood-prone areas near Charles Creek that no longer contain structures.

34

5.8 OPINIONS OF PROBABLE COSTS FOR FLOOD MITIGATION ALTERNATIVES
Concept level opinions of probable costs were developed for each of the investigated flood mitigation
alternatives. A summary of the cost estimates for each alternative (based on similar projects and unit
prices from local NCDOT bid tabs) can be found in Table 5-1. Initial project costs for each alternative were
calculated to mitigate flooding during the 10, 25, and 50-year storm events. It should be noted that the
costs for the protective berms and flood gate and pump system are listed as the same value for each storm
event. However, the protective berms are designed to mitigate damages for storms up to the 25-year
event and would not provide full flood protection during the 50-year storm event.
Table 5-1. Opinions of probable costs for flood mitigation alternatives
Alternative Probable Cost –
10-yr Storm
Probable Cost –
25-yr Storm
Probable Cost –
50-yr Storm
Protective Berms $2,200,000 $2,200,000 N/A
Flood Gate and Pump $7,000,000 $7,000,000 $7,000,000
Elevate Structures $900,000 $1,600,000 $2,100,000
Relocate Structures $2,700,000 $3,500,000 $4,000,000
Buyout $4,300,000 $7,500,000 $10,000,000
5.9 ESTIMATED FLOOD REDUCTION BENEFITS FOR FLOOD MITIGATION ALTERNATIVES
A complete cost-benefit analysis was conducted for each flood mitigation alternative. To determine the
flood reduction benefits, property damages incurred at different base flood elevations were estimated
using FIMAN’s online flood scenario tool. Based on water level data discussed in Section 4.2, computed
FEMA base flood elevations are reached more often than suggested by their given return period (i.e. the
10-year flood elevation has been reached six times in the last five years). Given this observation, each
storm’s respective water level was increased to provide a more conservative estimate of flood damages.
Water levels were interpolated and extrapolated for storm events that did not have a computed base
flood elevation. Adjusted water levels and corresponding damages obtained from FIMAN are provided in
Table 5-2.
Table 5-2. FIMAN water levels and estimated damages for various storm events
Storm Event FIMAN Water Level (ft.-NAVD) Estimated Damages
1-yr 1.5 $219,000
2-yr 2.0 $414,000
10-yr 3.0 $1,100,000
25-yr 3.5 $2,000,000
50-yr 4.5 $6,000,000
100-yr 5.5 $14,000,000

In order to calculate expected annual damages, the damages incurred during each storm event were
weighted based on their recurrence interval. From the estimated damages and project costs, a benefit-
cost ratio was calculated for each flood mitigation alternative based on FEMA procedures. A design life
of 50 years and an interest rate of 3% was assumed. Table 5-3 shows each alternative, the return period
for which it provides protection, respective project costs and benefits, and its benefit-cost ratio.

35

Annual maintenance costs were included in the total project cost calculation where necessary (e.g.
protective berms and flood gate and pump system). The annual lost tax value was included in the total
building demolition cost calculations.
Table 5-3. Cost-benefit analysis for flood mitigation alternatives
Flood Mitigation
Alternative
Return
Period
Initial Project
Cost
Present Worth
Total Project Cost
(Includes Flood
Damages)
Net Benefits
with Project
(Reduced Flood
Damages)
B/C
Protective Berms 25-yr $2,200,000 $5,000,000 $14,700,000 2.9
Flood Gate and Pumps 50-yr $7,000,000 $16,000,000 $17,000,000 1.1
Elevate Structures 50-yr $2,100,000 $2,100,000 $17,000,000 8.0
Relocate Structures 50-yr $4,000,000 $4,000,000 $17,000,000 4.3
Buyout 50-yr $10,000,000 $13,100,000 $17,000,000 1.3

Based on the cost-benefit analysis, the preferred flood mitigation alternatives are elevating or relocating
affected structures and the construction of multifunction protective berms. The elevation of flood-prone
structures is the most cost-effective option (benefit-cost ratio (B/C) of 8.0) followed by relocation (B/C =
4.3). Although the protective berms are less cost-effective, they do provide additional neighborhood
connectivity and recreational benefits and have a B/C ratio of 2.9.
While a majority of structures affected during flood events are residential homes, certain buildings along
the Pasquotank River waterfront that may be of public value experience flooding. These buildings include
Riverside Boatworks and properties owned by College of the Albemarle. Some affected properties are
located within the Shepard Street-South Road Street and Riverside Historic Districts (National Park
Service, 2018).
6 FUNDING APPROACHES
There are several federal grant programs as well as loan programs available to be pursued by the City for
flood mitigation, resiliency, and green infrastructure for stormwater management. These funding
opportunities are detailed below.
6.1 FEDERAL EMERGENCY MANAGEMENT AGENCY (FEMA) PROGRAMS
FEMA administers three programs to fund flood mitigation planning, projects that reduce disaster losses,
and projects that protect life and property from future disasters. FEMA distributes funds to each state for
management. In 2014, FEMA approved North Carolina’s Enhanced Hazard Mitigation Plan, making North
Carolina eligible for additional funds. Local governments are considered sub-applicants and must submit
applications for FEMA-appropriated funds to the North Carolina Division of Emergency Management. The
three programs are described below.

36

6.1.1 Hazard Mitigation Grant Program (HMGP)
The HMGP provides grants in response to a Presidential disaster declaration. Projects must provide a
long-term response to flood mitigation and disaster prevention such as elevating a home to reduce future
flood risk as opposed to buying sand bags and pumps to combat a single flood event. Projects must
produce a cost savings greater than the cost to implement the proposed project.
Types of projects that the City could consider in reducing risks associated with flooding and future
disasters include acquisition and structure demolition/relocation, floodplain and stream restoration,
stormwater management, and green infrastructure. Elizabeth City has several HMGP applications in
progress due to the Hurricane Matthew disaster declaration.
6.1.2 Pre-Disaster Mitigation (PDM) Program
The PDM program is intended to assist States, Tribes, local communities, etc. in implementing a
sustainable pre-disaster natural hazard mitigation program such that overall risk to life and structures
from future disasters is reduced and reliance upon federal funding is also reduced. Types of projects
eligible for PDM grants include property acquisition for open space conversion; elevating, relocating, or
retrofitting structures; and hydrologic, hydraulic, and engineering studies for flood mitigation.
6.1.3 Flood Mitigation Assistance (FMA) Program
The FMA program funds plans and projects that reduce and/or eliminate the risk of structural flooding for
properties insured under the National Flood Insurance Program (NFIP). Projects the City could consider
for FMA program grants include structure acquisition, demolition, and relocation for insured properties.
Properties must remain open space in perpetuity. Other minor structural flood mitigation measures are
also eligible under the FMA program.
6.2 US DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT (HUD) COMMUNITY
DEVELOPMENT BLOCK GRANT DISASTER RECOVERY (CDBG-DR) PROGRAM
HUD provides grants to assist in recovery from federally-declared disasters, especially in low-income
areas. CDBG-DR funds may cover a much broader range of activities (unlike FEMA) and can help
communities with limited resources begin recovery. Under the CDBG-DR program, Elizabeth City was
awarded a grant to replace and relocate sanitary sewer systems that failed during Hurricane Matthew.
6.3 CLEAN WATER MANAGEMENT TRUST FUND (CWMTF) GRANTS
The CWMTF grants funds for the purposes of improving water quality, sustaining ecological diversity,
protecting historic sites, restoring habitat, and reducing stormwater pollution. The CWMTF makes a
portion of their annual grants available for innovative stormwater projects. Innovative stormwater grants
may be used to improve stormwater management, reduce pollutants entering the State’s waterways,
improve water quality, and to research alternative solutions to water quality problems within the State.
Types of projects Elizabeth City may consider for application of an innovative stormwater CWMTF grant
include, but are not limited to, projects that:
 Reduce runoff volumes and rates;
 Promote infiltration and groundwater recharge;
 Sustainably maintain or improve hydrologic characteristics after land development;

37

 Remove pollutants of concern;
 Change attitudes, values, or behaviors; and
 Support or assist in restoration of natural systems.
The 2019 grant cycle will begin in late 2018 with training on the application process. Applicants must have
access to the Grant Management System (GMS) in order to submit their applications, which are typically
due at the beginning of February. Application review and site visits are conducted in the spring and grants
are usually awarded in September. Projects and approaches that document and/or improve
understanding of cost-benefit relationships of stormwater management systems may be considered more
competitive proposals.
6.4 NC DEPARTMENT OF ENVIRONMENTAL QUALITY (NCDEQ) WATER RESOURCES
DEVELOPMENT GRANT PROGRAM
This program provides 50 percent cost-share grants and technical assistance to local governments for
water management (flood control, shoreline stabilization, etc.), stream restoration, water-based
recreation (greenways, land acquisition, etc.) and engineering/feasibility studies. There are two grant
cycles per fiscal year: June 30th and December 31st. Projects funded by the NCDEQ Water Resources
Development Grant program in the past encompass replacement of failing drainage infrastructure,
construction of stormwater control measures to reduce flooding and provide water quality treatment,
and stream bank stabilization.
6.5 NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION COASTAL RESILIENCE GRANTS
PROGRAM
The NOAA Coastal Resilience Grants Program intends to build resiliency through projects that conserve
and restore ecosystem processes and functions and that reduce the vulnerability of coastal communities
and infrastructure from the impacts of changing oceanic conditions, extreme weather events, and climate
hazards. A pre-proposal is required to be submitted by March 7th for the 2018 grant cycle. Selected
applicants will be contacted to submit a full proposal based on the strength of the pre-proposal within 40
days of contact by NOAA. Grants must be funded at a 2:1 ratio. Therefore, if the City requested $100,000
in grant funds, they would need $50,000 in matching funds. The grant cycle is annual based on
appropriations by Congress and typically opens in January, with awards finalized in the early Fall.
6.6 ENVIRONMENTAL PROTECTION AGENCY (EPA) URBAN WATERS SMALL GRANT PROGRAM
The EPA Urban Waters Small Grant Program is open to many different entities including local governments
on a two-year cycle. The last grants awarded were in October of 2016. The EPA does not have a current
request for proposals online at this time; however, the City may visit the Urban Waters webpage to sign
up for updates and additional tools/information in the Urban Waters learning Network. To be eligible for
a grant (with individual awards up to $60,000), projects should address local water quality issues related
to urban runoff, provide additional community benefits, engage underserved communities, and foster
partnership. The City should consider following this grant source for future work in developing green

38

infrastructure to improve stormwater runoff and quality. Potential partners include nearby
colleges/universities, the public school system, waterfront businesses, and the Albemarle Commission.
6.7 EPA SECTION 205(J) GRANT PROGRAM
The EPA provides funding to States for water quality planning. North Carolina typically receives
approximately $100,000 annually which is administered through NCDEQ. These grants are specifically
earmarked for regional Council of Governments (COGs) like the Albemarle Commission. While the COGs
must be the specific grantee, they most often partner with local governments or private entities to achieve
environmental goals. Recent projects funded through the 205(j) grant program included projects that
improved both stormwater flood control and water quality. In 2016, the Eastern Carolina Council received
a 205(j) grant partnering with the Town of Newport to map the Town’s stormwater infrastructure and to
conduct outreach events for its citizens on how to properly maintain stormwater infrastructure. Other
types of projects funded include development of plans to restore natural runoff volumes for the Town of
Beaufort and stormwater assessments and BMP recommendations for school campuses in the Tar-
Pamlico and Neuse River basins.
The City may want to consider pursuing 205(j) grant funding for natural restoration and stormwater runoff
reduction planning through partnerships with the Albemarle Commission and the nearby colleges and
universities.
6.8 NATIONAL FISH AND WILDLIFE FOUNDATION (NFWF) FIVE STAR AND URBAN WATERS
RESTORATION GRANT PROGRAM
The NFWF Five Star and Urban Waters Restoration Grant Program operates on an annual cycle and is open
to any non-federal entity. Grants require a 1:1 match; however, the matching funds may be through in-
kind donated or volunteer services. The funding priorities for the program include on-the-ground
wetland, riparian, in-stream, and/or coastal habitat restoration, education and community outreach and
participation, particularly with K-12 schools, measurable benefits, and engagement with a diverse group
of community partners. The funding cycle typically begins in November with complete proposals due at
the end of January. Grants are awarded in July. The City could begin investigating the potential for green
infrastructure projects within the City and/or at City schools and riparian restoration along Charles Creek
for the 2019 grant cycle.
6.9 CLEAN WATER STATE REVOLVING FUND (CWSRF)
The CWSRF was established to replace the earlier Construction Grants program by amendments to the
Clean Water Act in 1987. With those amendments Congress provided funds for states to establish
revolving loan programs for funding of wastewater treatment facilities and projects associated with
estuary and nonpoint source programs (including stormwater best management practices and stream
restoration). The program makes low interest loans (½ of market rates) available with a limited amount
of principle forgiveness loans and some 0% interest loans for green projects. The CWSRF is operated by
the NCDEQ Division of Water Infrastructure and has two funding cycles annually in April and September.
Jennifer Haynie may be contacted for additional information at 919.707.9173 or at
[e-mail].

39

7 PRELIMINARY PLAN RECOMMENDATIONS
Moffatt & Nichol was selected to study and provide alternatives to reduce flooding and increase resilience
in the Charles Creek area of Elizabeth City. The elevation or relocation of buildings and use of protective
berms are recommended flood mitigation options for further study to increase flood resilience within the
City. Berms, along with the necessary road raises, provide protection against river flooding for storms as
large as the 25-year event. They also can be installed in conjunction with a greenway along Charles Creek
to improve connectivity between Mid-Atlantic Christian University and Elizabeth City State University. The
conceptual level initial cost of constructing berms with appropriate interior drainage infrastructure is
approximately $2.2 million, with a benefit-cost ratio of 2.9. Elevating affected buildings would cost about
$2.1 million to mitigate damages during the 50-year storm and has a benefit-cost ratio of 8.0. While the
elevation of flood-prone structures provides the highest benefit-cost ratio followed by relocating
structures (B/C = 4.3), the berm option does provide additional ancillary neighborhood connectivity and
recreational benefits. It should also be noted that, if preferred, a combination of the investigated
alternatives may be used instead of a singular flood mitigation alternative. A preliminary discussion with
permitting agencies determined that the flood gate/pump option would not be preferred and that use of
berms would also require further study to determine the level of wetland mitigation that may be needed
for construction. The installation of green infrastructure, as well as the revision of existing stormwater
and floodplain ordinances, serve as additional measures to improve resilience in Elizabeth City.
Ordinances should be revised to encourage the use of green infrastructure and implement new freeboard
requirements to provide additional safety and resilience. The flood gate and pump system has the lowest
benefit-cost ratio (B/C = 1.1) and also has the most permitting concerns, and therefore is not
recommended for further study.

40

8 REFERENCES
Chow, V. (1959). Open Channel Hydraulics. New York: McGraw-Hill Book Co.
City of Elizabeth City. (2017).
Federal Emergency Management Agency. (2009). Flood Insurance Study - Pasquotank County, North
Carolina.
National Park Service. (2018). National Register of Historic Places .
North Carolina Floodplain Mapping Program. (2017). Retrieved from Flood Inundation Mapping and
Alert Network: https://fiman.nc.gov/fiman/
North Carolina Floodplain Mapping Program. (2017). Flood Risk Information System.
North Carolina Floodplain Mapping Program. (2017). Spatial Data Download. Retrieved from QL2 LiDAR:
https://rmp.nc.gov/sdd/
North Carolina Floodplain Mapping Program. (2017). Spatial Data Download. Retrieved from Built
Environment: https://rmp.nc.gov/sdd/
US Army Corps of Engineers. (2016). HEC-RAS River Analysis System Hydraulic Reference Manual.
USGS. (2018). StreamStats.
XP Solutions. (2016). XP2D For Integrated 1D/2D Modeling - User's Manual.

41

Appendix A. TIDE EXCEEDANCE ANALYSIS AND RAINFALL RECORD

Figure A-1. Percent exceedance of water level at Mariners Wharf Park Pasquotank River gage

Never higher than 2.1
ft. above sea level
Rarely above 1.6 ft.
above sea level
3% of time -
1 ft. above
sea level
17% of time – 6 in.
or more above sea
level
50% of time – 0.1 ft.
or more above sea
level
88% of time – 6 in.
below sea level or
higher

42

Figure A-2. Percent exceedance of water level above 0 ft.-NAVD at Mariners Wharf Park Pasquotank River gage

43

Figure A-3. Precipitation record at Pasquotank River gage (2013-2017)

44

Appendix B. AFFECTED PROPERTIES DURING STORM EVENTS
Note: Affected properties are based on coarse modeling and should not be used for regulatory purposes. Parcels were only
included which contained structures based on available built environment data and the tables provided below.

Figure B-1. Flooded structures and parcels

45

10-yr Storm – Flooded Structures
Parcel Land Value Structure Value Total Value
1 3,900 7,600 11,500
2 3,600 0 3,600
3 3,800 5,400 9,200
4 3,500 18,400 21,900
5 10,600 29,300 39,900
6 12,200 17,900 30,100
7 9,600 40,000 49,600
8 29,100 34,200 63,300
9 10,800 0 10,800
10 18,700 29,000 47,700
11 7,400 29,700 37,100
12 7,800 29,700 37,500
13 7,200 51,900 59,100
14 6,000 32,200 38,200
15 6,900 43,500 50,400
16 9,200 36,200 45,400
17 14,900 0 14,900
18 34,300 8,900 43,200
19 20,300 68,000 88,300
20 4,600 35,900 40,500
21 5,600 30,600 36,200
22 5,600 57,900 63,500
23 20,200 16,100 36,300
24 10,400 49,700 60,100
25 8,600 18,300 26,900
26 9,800 22,300 32,100
27 29,100 148,600 177,700
28 24,000 5,600 29,600
29 11,900 40,000 51,900
30 37,600 90,700 128,300
31 21,500 19,800 41,300
32 4,100 12,600 16,700
33 10,700 35,600 46,300
34 14,700 44,600 59,300
35 79,900 0 79,900
36 187,600 2,000 189,600
37 474,400 8,500 482,900
38 37,200 101,600 138,800

46

Parcel Land Value Structure Value Total Value
39 16,100 88,800 104,900
40 11,300 49,100 60,400
41 20,100 199,200 219,300
42 34,700 0 34,700
43 19,000 127,700 146,700
44 12,500 91,500 104,000
45 10,900 24,900 35,800
46 8,000 23,900 31,900
47 46,000 0 46,000
48 24,500 148,600 173,100
49 6,200 33,900 40,100
50 10,100 0 10,100
51 13,500 20,900 34,400
52 11,800 0 11,800
53 9,900 41,300 51,200
54 7,800 0 7,800
55 16,100 36,000 52,100
Total 1,520,700 2,149,500 3,670,200

47

25-yr Storm – Flooded Structures
Parcel Land Value Structure Value Total Value
1 12,100 50,000 62,100
2 10,300 32,600 42,900
3 21,400 42,700 64,100
4 3,900 7,600 11,500
5 3,600 0 3,600
6 10,900 25,300 36,200
7 10,900 31,900 42,800
8 3,800 5,400 9,200
9 3,500 18,400 21,900
10 10,600 29,300 39,900
11 44,200 49,400 93,600
12 23,800 0 23,800
13 9,300 35,200 44,500
14 12,200 17,900 30,100
15 7,900 22,800 30,700
16 9,600 40,000 49,600
17 29,100 34,200 63,300
18 10,800 0 10,800
19 18,700 29,000 47,700
20 7,400 29,700 37,100
21 7,800 29,700 37,500
22 7,200 51,900 59,100
23 6,000 32,200 38,200
24 6,900 43,500 50,400
25 9,200 36,200 45,400
26 14,900 0 14,900
27 16,700 29,300 46,000
28 11,600 29,300 40,900
29 34,300 8,900 43,200
30 1,900 0 1,900
31 20,300 68,000 88,300
32 5,600 31,100 36,700
33 4,600 35,900 40,500
34 4,200 13,800 18,000
35 5,600 30,600 36,200
36 5,600 57,900 63,500
37 20,200 16,100 36,300
38 15,000 61,200 76,200

48

Parcel Land Value Structure Value Total Value
39 9,600 24,600 34,200
40 10,400 49,700 60,100
41 8,600 18,300 26,900
42 9,800 22,300 32,100
43 45,400 0 45,400
44 29,100 148,600 177,700
45 15,600 59,500 75,100
46 24,000 5,600 29,600
47 11,900 40,000 51,900
48 13,200 27,400 40,600
49 9,400 45,300 54,700
50 37,600 90,700 128,300
51 21,500 19,800 41,300
52 4,100 12,600 16,700
53 10,700 35,600 46,300
54 17,300 14,900 32,200
55 23,900 0 23,900
56 14,700 44,600 59,300
57 14,700 43,600 58,300
58 34,200 0 34,200
59 12,400 43,400 55,800
60 11,900 33,400 45,300
61 102,100 50,100 152,200
62 12,700 105,700 118,400
63 79,900 0 79,900
64 187,600 2,000 189,600
65 474,400 8,500 482,900
66 12,500 62,500 75,000
67 37,200 101,600 138,800
68 16,100 88,800 104,900
69 11,300 49,100 60,400
70 20,100 199,200 219,300
71 12,800 500 13,300
72 34,700 0 34,700
73 19,000 127,700 146,700
74 15,300 85,400 100,700
75 12,500 91,500 104,000
76 21,200 77,200 98,400
77 18,700 38,300 57,000

49

Parcel Land Value Structure Value Total Value
78 16,800 63,500 80,300
79 17,600 70,100 87,700
80 4,600 23,400 28,000
81 19,300 33,400 57,200
82 10,900 24,900 35,800
83 16,700 48,600 65,300
84 9,100 87,400 96,500
85 8,000 23,900 31,900
86 46,000 0 46,000
87 10,000 10,700 20,700
88 5,800 27,400 33,200
89 24,500 148,600 173,100
90 3,800 0 3,800
91 6,200 66,400 72,600
92 6,200 33,900 40,100
93 12,800 102,800 115,600
94 11,100 27,400 38,500
95 10,100 0 10,100
96 13,500 20,900 34,400
97 17,700 62,100 79,800
98 30,300 59,100 89,400
99 6,700 57,600 64,300
100 13,600 35,600 49,200
101 11,800 0 11,800
102 9,900 41,300 51,200
103 7,800 0 7,800
104 16,100 36,000 52,100
Total 2,306,600 4,054,500 6,361,100

50

50-yr Storm – Flooded Structures
Parcel Land Value Structure Value Total Value
1 12,100 50,000 62,100
2 10,300 32,600 42,900
3 21,400 42,700 64,100
4 3,900 7,600 11,500
5 3,600 0 3,600
6 10,900 25,300 36,200
7 10,900 31,900 42,800
8 3,800 5,400 9,200
9 3,500 18,400 21,900
10 8,800 10,600 19,400
11 10,600 29,300 39,900
12 9,400 23,900 33,300
13 7,900 34,700 42,600
14 7,200 54,100 61,300
15 44,200 49,400 93,600
16 19,000 42,600 61,600
17 23,800 0 23,800
18 33,200 67,900 101,100
19 9,300 35,200 44,500
20 13,300 82,100 95,400
21 12,200 17,900 30,100
22 7,900 22,800 30,700
23 9,600 40,000 49,600
24 29,100 34,200 63,300
25 10,800 0 10,800
26 18,700 29,000 47,700
27 7,400 29,700 37,100
28 7,800 29,700 37,500
29 7,200 51,900 59,100
30 25,200 47,300 72,500
31 6,000 32,200 38,200
32 6,900 43,500 50,400
33 11,900 12,200 24,100
34 7,000 17,600 24,600
35 6,000 56,800 62,800
36 9,200 36,200 45,400
37 8,000 18,900 26,900
38 14,900 0 14,900

51

Parcel Land Value Structure Value Total Value
39 8,200 63,800 72,000
40 16,700 29,300 46,000
41 11,600 29,300 40,900
42 15,500 34,900 50,400
43 34,300 8,900 43,200
44 1,900 0 1,900
45 20,300 68,000 88,300
46 5,600 31,100 36,700
47 4,600 35,900 40,500
48 4,200 13,800 18,000
49 5,600 30,600 36,200
50 5,600 57,900 63,500
51 20,200 16,100 36,300
52 15,000 61,200 76,200
53 8,000 24,700 32,700
54 9,600 24,600 34,200
55 10,400 49,700 60,100
56 8,600 18,300 26,900
57 9,800 22,300 32,100
58 45,400 0 45,400
59 29,100 148,600 177,700
60 15,600 59,500 75,100
61 8,700 10,600 19,300
62 24,000 5,600 29,600
63 11,900 40,000 51,900
64 13,200 27,400 40,600
65 7,800 14,000 21,800
66 15,000 70,300 85,300
67 9,400 45,300 54,700
68 37,600 90,700 128,300
69 21,500 19,800 41,300
70 18,700 111,200 129,900
71 4,100 12,600 16,700
72 10,700 35,600 46,300
73 17,300 14,900 32,200
74 23,900 0 23,900
75 31,200 130,600 161,800
76 14,700 44,600 59,300
77 14,700 43,600 58,300

52

Parcel Land Value Structure Value Total Value
78 24,900 41,400 66,300
79 34,200 0 34,200
80 12,400 43,400 55,800
81 11,900 33,400 45,300
82 102,100 50,100 152,200
83 12,700 105,700 118,400
84 79,900 0 79,900
85 187,600 2,000 189,600
86 474,400 8,500 482,900
87 12,500 62,500 75,000
88 12,800 51,600 64,400
89 37,200 101,600 138,800
90 16,100 88,800 104,900
91 11,300 49,100 60,400
92 20,100 199,200 219,300
93 12,800 500 13,300
94 34,700 0 34,700
95 19,000 127,700 146,700
96 15,300 85,400 100,700
97 12,500 91,500 104,000
98 21,200 77,200 98,400
99 18,700 38,300 57,000
100 16,800 63,500 80,300
101 17,600 70,100 87,700
102 4,600 23,400 28,000
103 19,300 33,400 57,200
104 9,200 42,700 51,900
105 10,900 24,900 35,800
106 16,700 48,600 65,300
107 9,100 87,400 96,500
108 8,000 23,900 31,900
109 46,000 0 46,000
110 10,000 10,700 20,700
111 5,900 0 5,900
112 5,800 27,400 33,200
113 24,500 148,600 173,100
114 3,800 0 3,800
115 6,200 66,400 72,600
116 6,200 33,900 40,100

53

Parcel Land Value Structure Value Total Value
117 12,800 102,800 115,600
118 6,200 65,200 71,400
119 11,100 27,400 38,500
120 10,100 0 10,100
121 13,500 20,900 34,400
122 19,700 48,700 68,400
123 19,700 53,700 73,400
124 19,600 48,700 68,300
125 17,700 62,100 79,800
126 8,300 9,300 17,600
127 30,300 59,100 89,400
128 6,700 57,600 64,300
129 13,600 35,600 49,200
130 11,700 0 11,700
131 11,800 0 11,800
132 19,600 61,900 81,500
133 19,600 36,300 55,900
134 19,600 82,200 101,800
135 19,600 96,700 116,300
136 19,700 38,300 58,000
137 9,900 41,300 51,200
138 7,800 0 7,800
139 16,100 36,000 52,100
140 7,800 43,500 51,300
Total 2,820,500 5,703,500 8,524,000

54

Appendix C. PUBLIC INVOLVEMENT AND ENGAGEMENT

An important component of any flood mitigation planning process is public participation. Individual
citizen and community-based input provides the planning team with a greater understanding of local
concerns and increases the likelihood of successfully implementing mitigation activities by developing
community “buy-in” from those directly affected by the decisions of public officials. As citizens become
more involved in decisions that affect their safety, they are more likely to gain a greater appreciation of
the hazards present in their community and take the steps necessary to reduce their impact. Public
awareness is a key component of any community’s overall mitigation strategy aimed at making a home,
neighborhood, school, business, or entire planning area safer from the potential effects of the flood
hazard.
Meaningful public involvement in the development of the Charles Creek Flood Mitigation Plan was sought
using multiple methods including open public meetings, an online public participation survey that doubled
as a project information portal, and by making draft copies of plan materials and preliminary findings
available at the open public meetings for public input. Public meetings were held at three pre-determined
points during the planning process: (1) near the beginning of the planning process; and (2) once an
approximately 60% draft of the plan had been developed in order to gauge public perception of the
preliminary draft; and (3) near the end of the planning process. These public meetings were held at a
central location to the planning area to ensure that interested citizens had reasonable access to the
opportunity to participate in-person in the planning process. The online public participation survey was
promoted via social media outlets, email, and at project meetings and the second public open house.
PUBLIC OPEN HOUSES
Three public open house meetings were held to solicit public input. The dates of these three events are
provided below.
Public Open House #1: October 18th, 2017
Public Open House #2: January 17th and 18th, 2018
Public Open House #3: March 5th and 6th, 2018
[Note: Moffatt & Nichol did not host or participate in Public Open House #3, however, M&N did provide meeting
materials for the City Planning Department to use in carrying out this meeting.]
During the day, the public open houses provided opportunities for citizens to view preliminary plan
exhibits and provided feedback on proposed design concepts to M&N team members in attendance.
While the exhibits were available for viewing, other members of the M&N team attended meetings with
various City groups and committees to present plan materials. Formal presentations of the plan concepts
were given during the evenings of open house days, providing an additional opportunity for members of
the community to view project work to date as well as ask questions and provide input. Those who
attended the public open houses and concurrent small-group meetings were directed to the online public
participation survey to provide additional project feedback if desired.

55

ONLINE PUBLIC PARTICIPATION SURVEY
The online public participation survey was formally titled the Elizabeth City Waterfront Vision Plan Survey
and was made available on January 17th, 2018 and remained available until February 9th, 2018. During
this time, over 3,000 website views and 368 unique survey responses were received. The survey itself is
closed but is still available online for reference at www.harborofhospitality.com. Feedback from the
survey was used to guide and refine draft planning concepts.
The survey provided respondents with preliminary design concepts and plan exhibits on which to base
their responses. The following is a high-level summary of the responses obtained through the survey
related to flood mitigation and resiliency:
 When asked on a scale of 1 to 5 how well the alternatives create greener spaces and landscaping
while also promoting resiliency, 17% said 5 (i.e., “very well”), 38% said 4, 24% said 3, 8% said 2,
4% said 1 (i.e., not very well), and 12% said they were not sure (Figure C-1).

Figure C-1. Online survey question results

 When asked whether or not the respondents felt the proposed concepts would bring greater
economic vitality to Elizabeth City, a key indicator of resilience, 79% said yes, 5% said no, and 17%
said they were not sure (Figure C-2).

Figure C-2. Online survey question results
4%
8%
23%
37%
16%
12%
How well do the alternatives create greener spaces and
landscaping while, at the same time, promoting resiliency?
1 - Not Very Well
2
3
4
5 - Very Well
Not Sure
78%
5%
17%
Will the proposed concepts bring greater economic vitality
to Elizabeth City, a key indicator of resilience?
Yes
No
Not Sure

56

Appendix D. POST-FLOOD RECOVERY STRATEGIES TO IMPROVE
RESILIENCE

UTILIZE SECTION 406 PUBLIC ASSISTANCE PROGRAM FUNDING FOR RECOVERY-BASED MITIGATION
The Section 406 public assistance program is managed by the State of North Carolina utilizing funding
provided for in the Robert T. Stafford Disaster Relief and Emergency Assistance Act (Stafford Act) via
FEMA’s Public Assistance (PA) program. Section 406 funding provides discretionary authority to fund
mitigation measures in conjunction with the repair of eligible disaster-damaged facilities in declared
counties following a presidentially-declared flood event. Section 406 funding must be applied to
portions of the facility that were damaged by the flood event and the mitigation measure must be
intended to directly reduce the potential for future, similar damages to the same facility. Additional
information pertaining to both pre- and post-disaster mitigation funding opportunities to be pursued by
the City can be found in Section 6.
EDUCATE PROPERTY OWNERS ABOUT FLOOD MITIGATION IN THE POST-DISASTER ENVIRONMENT
The post-disaster environment can be a valuable time for public education and outreach regarding
mitigation activities in which property owners can engage in to manage future flood risk. Immediately
following a disaster, the mindset of most impacted individuals is to repair or replace damaged assets as
quickly as possible in order to return to normal conditions. With proper education, property owners can
be made aware of post-flood recovery options that help alleviate future, similar damages through post-
event mitigation.
Education and outreach efforts can be widely varied, but may include: facilitating technical assistance
programs that address measures that citizens can take; facilitating community workshops on potential
funding sources for mitigation measures; encouraging the City and homeowners to install backflow
valves on stormwater infrastructure to prevent reverse-flow flood damage; encouraging residents in
flood-prone areas to elevate, relocate, or retrofit homes; educating the public about securing debris,
propane tanks, yard items, and stored objects that may otherwise be swept away, damaged, or pose a
hazard to surrounding residents; asking residents to help keep storm drains clear of debris during
storms; and encouraging local business owners to have a continuity of operations plan in place.
Community-based outreach efforts should be carried out by the City to the greatest extent practicable,
particularly following flood events, as a meaningful way to alleviate future flood risk and maximize
public involvement in the flood mitigation planning process.
ACTIVELY SEEK TO ESTABLISH NEW OPEN SPACE OPTIONS
By default, floodplain properties acquired through FEMA grant programs must be maintained as open
space according to the requirements of the funding program. However, in the post-flood environment,
other opportunities to establish open space within the Charles Creek area may become apparent
through other grants, donations, etc. This may include lands that can be used for greenways, walking

57

and biking trails, cultural and historic awareness, natural resource protection, and other options that
minimize future flood risks. The post-disaster environment typically heightens awareness of flooding
issues and may also be an opportune time to seek funding for the purchase of lands to be used as open
space. The active pursuit of grant opportunities to maintain the presence of open space around Charles
Creek is an important post-flood mitigation strategy to be carried out by the City.
PURSUE PROJECTS IDENTIFIED IN THE PASQUOTANK COUNTY RESILIENT REDEVELOPMENT PLAN
The Pasquotank County Resilient Redevelopment Plan was created by the North Carolina Division of
Emergency Management following Hurricane Matthew to develop strategic recovery actions and
determine any unmet funding needs required to implement these actions. These plans also provide the
basis for the state’s Recovery Action Plan required by the U.S. Department of Housing and Urban
Development (HUD) to spend funds allocated through the Community Development Block Grant –
Disaster Relief (CDBG-DR) program. The Pasquotank County plan identifies 22 specific recovery projects
that are divided into four pillars: infrastructure (11 projects), housing (5 projects), economic development
(4 projects), and environment (2 projects). Projects are prioritized based on a number of factors, including
but not limited to technical feasibility, economic benefits, and effectiveness of risk reduction. Several of
the identified projects specifically target areas within Elizabeth City. For some of these actions,
implementation has already begun. As of May 2017, Pasquotank County and the City of Elizabeth City
had multiple FEMA Hazard Mitigation Grant Program (HMGP) applications underway to aid in completing
these projects. Any applications and projects that are not funded by the HMGP will attempt to be matched
to an appropriate funding stream. Those that are not matched should be incorporated into the County’s
Hazard Mitigation Plan for consideration for future funding sources to meet project needs. It is vital that
the City and County implement as many identified actions as is feasible to improve resilience. Additional
information on available funding sources is provided in Section 6. The complete Pasquotank County
Resilient Redevelopment Plan can be found online:
https://files.nc.gov/rebuildnc/documents/matthew/rebuildnc_pasquotank_plan_combined.pdf.

58

Appendix E. CHARLES CREEK FLOODING PHOTOS
Flooding photos taken along Charles Creek following a rain event. Photos courtesy of City of Elizabeth City.

59

60

Appendix F. PERMIT SCOPING MEETING MINUTES

61

Summary of Permit Agency Scoping Meeting for Charles Creek Flood Mitigation Plan
April 10, 2018 – 10 AM – Washington Regional Office

Attendees – (see sign in sheet)
The meeting began with a brief presentation of the project, initial findings, and recommendations. The
preliminary recommendations at this stage for further study and consideration are the
elevation/relocation of structures or the construction of flood protection berms that would serve a dual
purpose of providing connectivity to the waterfront as greenways.
The meeting then focused on getting permit agency feedback on the alternatives with special
consideration of the berm and gate/pump alternatives, as those would likely be the only alternatives that
would require permits.
Based on discussion with the agencies, the main concerns and feedback were as follows:
Berm Alternative
- Wetlands – The US Army Corps of Engineers (USACE) stated that if the protective berm option
were selected for further study, a wetland delineation would have to be completed along the path
of the berms in order to define and quantify potentially affected wetland areas. All agencies
agreed and stated that berms should ideally be located in areas of higher ground where flood
protection can still be provided while minimizing wetland impacts. The NC Wildlife Resources
Commission (NCWRC) stated that even if vertical sheetpiling is used, consideration will still have
to be given to areas landward of the sheetpiling that are currently wetlands. If waters can no
longer reach those areas, they will be impacted. The NC Division of Water Resources (NCDWR)
concurred and stated that those existing landward wetland areas would be considered a loss of
use. The USACE stated that wetland mitigation would likely be required for any affected wetlands,
but that they could not state at this time whether on-site mitigation would be allowed. That
would not be determined until the wetland delineation was completed at a later design stage.
- Public Trust Waters – NC Division of Coastal Management (NCDCM) stated that berms located
within the 30-foot buffer zone of Public Trust Waters should be studied further to ensure that
they do not cause increased runoff to these waters, or cause funneling or redirection of waters to
other areas and thereby increasing their flood levels. NCWRC and the US Fish and Wildlife Service
(USFWS) concurred.
Flood Gate/Pump Alternative
- Fisheries – Significant concerns were raised by all agencies with the flood gate and pumps
alternative. Most concerns centered about the system’s potential detrimental effects on the
spawning and migratory behaviors of anadromous fish populations (Blueback Herring and the
Alewife) in Charles Creek, which is a designated anadromous fish spawning area with moratoria
set from Feb 15 thru Jun 15 (stated by NCDCM-Fisheries). The concern with a gate structure is
that there will be pressure to operate and close the gates even during this moratoria due to
nor’easters which are prevalent during that time. NCWRC and NCDCM-Fisheries have fish
population and monitoring data, so these agencies should be consulted about providing the data

62

if the gate/pump alternative is studied further. NCDWR and NCWRC stated that a significant
operations and maintenance plan would have to be developed for the gate closures and pump
operations so that potential effects could be accurately quantified and that significant limits on
times the system could be operated may be part of permit conditions.
- Wetlands – The US Army Corps of Engineers (USACE) stated that depending on how often the gate
would be operated, there may be effects on wetlands with this option as well.
Elevate/Relocate Structures Alternatives
All agencies agreed that these flood mitigation options would be preferred from a permitting perspective,
but understand that some property owners may not be amenable to them. USFWS asked that
combinations of these options be explored and that hopefully those not open to relocation would at least
be open to elevation of their homes. USFWS also stated that relocation would allow for potential
expansion of existing wetlands and offer an opportunity for wetland restoration. NCWRC and NCDCM
stated that opportunities for collaboration between Elizabeth City State University and the Coastal Studies
Institute should be explored for additional wetland planting and enhancement along Charles Creek. It
was stated that all of these options (and combinations) would be considered and that implementation of
any alternatives would be subject to available project funding.
Overall Summary
All agencies reiterated that elevation and/or relocation of structures would be preferred. They agreed
with the recommendations concerning the allowance of the use of green infrastructure within City
stormwater ordinances and that allowing for additional freeboard to current FEMA flood levels would
increase flood resilience in the Charles Creek watershed. The utilization of berms may also be allowed
from a permitting perspective but the potential wetland effects, mitigation requirements, and a
confirmation of no redirection of floodwaters would all have to be studied further. The flood gate/pump
alternative by far had the most concerns from all the agencies, and they all agreed that the permitting
path for approval of that option was not certain, and that many roadblocks could present a fatal flaw to
that alternative.

1776 Statesville Avenue,
Suite 12, Charlotte NC 28206
www.moffattnichol.com