1998-07-27 Work Session
NEW HANOVER COUNTY BOARD OF COMMISSIONERSBOOK 26
WORK SESSION ON STORMWATER DRAINAGE, JULY 27, 1998PAGE 596
ASSEMBLY
The New Hanover County Board of Commissioners held a Work Session on Monday, July
27, 1998, at 5:30 p.m. in Room 501 of the New Hanover County Administration Building, 320
Chestnut Street, Wilmington, North Carolina.
Members present were: Commissioners Buzz Birzenieks; Ted Davis, Jr.; Charles R. Howell;
Vice-Chairman Robert G. Greer; Chairman William A. Caster; County Manager, Allen O’Neal;
County Attorney, Wanda M. Copley; and Clerk to the Board, Lucie F. Harrell.
Chairman Caster called the meeting to order and welcomed the following members of the City
Council: Mayor Hamilton E. Hicks, Jr.; Councilmember Frank S. Conlon; Councilmember Harper
Peterson; Councilmember Jim Quinn; and Councilmember Charlie Rivenbark. He reported the
purpose of the meeting was to discuss the findings of the Pages Creek Watershed Study since this was
an issue that involved the entire county.
Mr. Dan Dawson, representing W. K. Dickson & Company, Inc., reported the Pages Creek
Study was initiated by New Hanover County to assess the existing stormwater conditions, evaluate
alternative stormwater management techniques and submit recommendations for improving
stormwater management in New Hanover County through the study of the Pages Creek watershed.
The assessment portion of the Pages Creek Study consisted of a review of previous
stormwater studies, a detailed hydrologic study of the drainage conditions of the watershed, and a
review of the existing stormwater regulatory programs.
Numerous drainage and water studies have been conducted in New Hanover County. In
1981, a comprehensive study was performed that recommended the establishment of a county
drainage organization to manage stormwater throughout the county. Since that time, other studies
have been initiated and carried out by the University of North Carolina at Wilmington and the
Planning Department. Findings from these studies indicate a need to establish a formal drainage plan
for New Hanover County.
The hydrologic study investigated the existing and anticipated future watershed stormwater
runoff characteristics of Pages Creek to identify drainage system improvements and estimated costs
to construct the improvements. The runoff analysis utilized the 24-hour precipitation rates for rainfall
events with recurrence intervals of 2, 5, 25, 50 and 100 years predicted from statistical data published
by the National Weather Service. The analysis determined runoff discharge rates and volumes to
assess the capacities of the culverts and channels in the drainage conveyance system of the watershed.
The study determined that the existing twenty (20) culverts and eleven (11) miles of channels
do not currently have the hydraulic capacities to convey runoff of a ten (10) year rainfall event
without inundating upstream and adjoining land which creates flooding problems. The cost to replace
the culverts is estimated at $287,000, and the cost to restore the channels is $4,600,000 of which
$900,000 is estimated to be land acquisition costs.
Culvert replacement and stream restoration construction activities will significantly impact
existing wetlands and the water quality of receiving streams. The federal and state programs
protecting wetlands and surface water quality require mitigative measures when construction
activities impact wetlands. To mitigate these impacts, new wetlands will have to be constructed in
non-wetland areas. The estimated cost of mitigating the impacts of channel restoration through the
construction of new wetlands is $32,400,000 of which $16,400,000 is estimated to be costs
associated with land acquisition.
Flooding problems in the Pages Creek Watershed can be resolved. The issue to deal with is
the mitigation of environmental damages when addressing flooding problems. Culvert replacements
are minor with a temporary impact on traffic. Improving the capacity of channels is more difficult
because disturbing more than one acre of land requires a State permit which
NEW HANOVER COUNTY BOARD OF COMMISSIONERSBOOK 26
WORK SESSION ON STORMWATER DRAINAGE, JULY 27, 1998PAGE 597
outlines regulations that have to be followed in mitigating environmental impacts. This process is
quite costly.
Typically, wet ponds have been the technique used to treat stormwater; however, there are
very few sites along estuarine waters that are suitable for wet ponds. In order to mitigate the
environmental impacts, it is recommended that wetlands be constructed in the downstream reaches
or along the sides of channels just before the estuarine area. The water would be intercepted down
the basin and diverted over to non-wetland areas that have been converted to wetlands.
Non-wetland areas adjacent to estuarine waters in New Hanover County have another
definition. This definition is waterfront land, which usually has residential development on the
property. In order to mitigate environmental impacts on Pages Creek to construct new wetlands, land
would have to be acquired at an approximate cost of $16,000,000 with an additional $16,000,000
needed to construct new wetlands.
New Hanover County should develop and implement a comprehensive stormwater
management program. The rapid growth of residential and commercial development has begun to
exceed the conveyance and assimilation capacities of natural streams. Without a comprehensive
stormwater management program, the flooding and water quality problems will continue to grow with
development. The program should provide for an integrated response to growth through appropriate
planning, financing, and standards and policies that are effective, equitable and economical. The
program should be tailored to the specific needs and the public policy objectives of New Hanover
County.
Consideration should be given to separating the program into the following categories:
(1)Ordinances and policies
(2)Drainage Master Plan
(3)Storm Drainage Manual
(4)County Stormwater Database
(5)Training and Public Education Programs
(6)Financial Management Strategies
The elements of the program are interconnected and need to be developed over time. It is
unreasonable to believe that a complete, functional program can be implemented in a short period of
time. It would make more sense to grow into a program one step at a time. Extensive discussion
should begin immediately to identify the features needed in the County now and in the future.
Since some of the watersheds in the County extend into portions of the City, the County may
need to utilize a Watershed Management District Program for generating funds and establishing
maintenance priorities.
There are a variety of options for financing stormwater systems. The idea of a stormwater
utility is new in North Carolina and has not been accepted in some cases. Other alternatives are
general tax revenues, special assessments, impact fees, general obligation bonds, revenue bonds,
public/private participation, private financing, and a Watershed District Tax.
Mr. Dawson advised on August 7, 2001, the Phase II Stormwater Rules of the National
Pollutant Discharge Elimination System (NPDES) will require the City and County to apply for
stormwater permits for all discharging culverts. EPA is focusing on the best management of
stormwater runoff. Larger cities have already been required to obtain permits for drainage systems.
This means the systems have been inventoried, mapped through GIS systems and monitored
constantly for water quality and pollutant loading. Small stormwater systems, referred to as Phase
II Systems, will fall under the same requirements in 2001. These regulations will impact 19,000 to
20,000 local governments.
NEW HANOVER COUNTY BOARD OF COMMISSIONERSBOOK 26
WORK SESSION ON STORMWATER DRAINAGE, JULY 27, 1998PAGE 598
In closing, Mr. Dawson stated that watersheds do not recognize political boundaries, nor do
water systems depend on gravity to distribute water throughout a community. Water is produced by
surface or groundwater supplies. Water is treated to an acceptable level where energy is added to
pressurize the system to either store or distribute to the users. With enough horsepower or elevated
storage, water systems can continue to evolve and expand regardless of watersheds. Sanitary sewer
systems have small flow rates; therefore, the wastewater can be pumped several times over ridges to
be treated at wastewater treatment plants.
Drainage is not like water or sewer. Rainfall is unpredictable and drainage must be installed
to meet extreme events. This is an ideal time for New Hanover County and the City of Wilmington
to work together in better managing drainage.
Mr. Dawson advised that he would be glad to answer questions.
Chairman Caster requested Mr. Dawson to explain why the culverts installed throughout New
Hanover County by the N. C. Department of Transportation do not meet the requirements of the
area?
Mr. Dawson responded the culverts are structurally sound; however, with years of rapid
development, the cumulative impact from upstream development has overloaded many existing
culverts. Also, many people feel that the Department of Transportation should be involved with
constructing roads not building drainage systems. If a uniform Drainage Manual is implemented by
New Hanover County, the size of culverts for road and drainage systems can exceed the dimensions
required by the Department of Transportation. The GIS Program combined with a Master Drainage
Plan will allow for good planning and development of a stormwater department. This department will
determine the impact of development on a watershed and consistently apply a uniform set of rules and
regulations to mitigate environmental impacts. This process will allow the County to manage future
development activities.
Discussion was held on the importance of providing Training and Public Education Programs
to the citizens. This process should involve staff, designers, contractors, developers, homeowners,
and the public with different programs administered to various groups. The first step in moving
forward with developing and implementing a drainage program is to have a well informed public.
After referencing funding options for implementing an drainage system, Chairman Caster
requested Mr. Dawson to explain how drainage can be financed through revenue bonds.
Mr. Dawson said that establishment of a Stormwater Utility District will allow the County to
charge a user fee that will provide the necessary funding to retire revenue bonds. Eventually, the
governing bodies will have to decide how much money can be spent to implement an acceptable level
of drainage.
A lengthy discussion was held on the problems that will be experienced with condemning
properties to construct wetlands. Councilmember Peterson questioned whether the study had
addressed land use as a control measure.
Mr. Dawson responded that land use is important in managing drainage; however, this is an
issue that must be determined by the elected officials of each governmental entity. Drainage, water
and sewer are utilities. When W.K. Dickson and Company, Inc. was hired to perform the drainage
study, the charge was to provide a recommendation that would provide the best service for the least
cost.
Discussion was held on the delineation of wetlands. Mr. Dawson reported there are
advantages and disadvantages to adopting regulations that will require delineation of wetlands before
construction can begin. If a policy is adopted, the developer would be required to submit an
approved map of delineated wetlands by the Corps of Engineers when the plan is submitted to the
Planning Department. This procedure would be beneficial in better controlling drainage in new
subdivisions, but the price of a home would increase. Currently, the County does not
NEW HANOVER COUNTY BOARD OF COMMISSIONERSBOOK 26
WORK SESSION ON STORMWATER DRAINAGE, JULY 27, 1998PAGE 599
require delineation maps approved by the Corps of Engineers before erosion control permits are
issued. In some instances, developers have moved forward with designing and planning a project
with a considerable sum of money invested. If the wetlands are not properly delineated when
applying for an erosion control permit, the Corps of Engineers will require the developer to re-design
the project, which can be quite costly. At some point the County must determine if wetland
delineation is needed for subdivisions only, or for all soil erosion plans.
Councilmember Peterson asked if the impact of water quality to a watershed with
development of land over one or two acres had been included in the study?
Mr. Dawson responded that cumulative environmental impacts should be considered through
public policy in a comprehensive Stormwater Management Plan that is enforced by trained and
experienced stormwater management staff to prevent continued development without adequate
drainage.
A lengthy discussion followed on the next step to be taken by New Hanover County in better
controlling drainage. Mr. Dawson recommended using the GIS System and Planning Department to
collect raw data on the watersheds, culverts, and runoff conditions so a baseline can be established.
During this collection period, the County should focus on policies and procedures that would require
approved maps of delineated wetlands by the Corps of Engineers before a comprehensive stormwater
management plan is developed. Many policy decisions will have to be made by the Board of County
Commissioners.
Commissioner Birzenieks asked if culverts were upgraded and snag and drag projects were
completed, would drainage conditions be improved.?
Mr. Dawson advised this action would be helpful; however, a plan will have to be
implemented that will address drainage, water quality, and flooding.
Commissioner Howell questioned whether reviewing drainage work performed by the City
would be helpful to New Hanover County.
Mayor Hicks offered to share any of the services and work performed on drainage by the City
of Wilmington.
A lengthy discussion ensued on construction occurring in wetlands. Mr. Dawson reported
the Planning Director receives numerous reports of construction violations in wetlands or in the flood
plain. Again, the County must develop a uniform drainage plan enforced by trained and experienced
stormwater management staff to prevent violations of this type.
Commissioner Howell stressed the importance of everyone understanding that New Hanover
County has adopted regulations to better control drainage. Currently, all subdivisions must comply
with drainage regulations, whether being required to construct a retention pond or use another
procedure. He stated, as a contractor, it was difficult for him to understand how construction occurs
in wetlands in New Hanover County.
Vice-Chairman Greer expressed concern for developers building in wetlands and stated
policies should be adopted to alleviate this problem.
Assistant County Manager Dave Weaver suggested considering recommendations that would
address existing drainage problems through more stringent stormwater regulations. This would
increase the cost of new housing, but cost-wise would be cheaper to the County in lieu of wetland
mitigation or stream channels.
Councilmember Rivenbark spoke of the public opposition that might be received in developing
and adopting land use policies and stormwater regulations. He emphasized the importance of moving
forward with addressing the drainage problems county-wide.
NEW HANOVER COUNTY BOARD OF COMMISSIONERSBOOK 26
WORK SESSION ON STORMWATER DRAINAGE, JULY 27, 1998PAGE 600
Mayor Hicks asked if re-mapping the 100 year flood plain line would have an impact on a
comprehensive Stormwater Management Program?
Mr. Dawson responded it was a good idea to update the flood plain line, but he did not feel
there should be a delay in moving forward with a Stormwater Management Program.
Chairman Caster, on behalf of the Board, complimented Mr. Dawson for an excellent report,
and he expressed appreciation to the members of the City Council for their comments and interest in
the drainage issue.
MEETING CONVENED FROM REGULAR SESSION TO CLOSED SESSION
Chairman Caster called for a vote to convene from Regular Session to Closed Session to
consult with the County Attorney regarding an administrative procedure pursuant to NCGS 143-
318.11(3).
Motion:
Commissioner Birzenieks MOVED, SECONDED by Commissioner Howell to convene to
Closed Session. Upon vote, the MOTION CARRIED UNANIMOUSLY.
Chairman Caster convened from Regular Session to Closed Session at 7:35 p.m.
Motion:
Commissioner Davis MOVED, SECONDED by Commissioner Birzenieks to reconvene to
Regular Session.
Chairman Caster reconvened from Closed Session to Regular Session at 9:20 p.m., and he
reported that no action was taken in the Closed Session.
ADJOURNMENT
Motion:
Commissioner Birzenieks MOVED, SECONDED by Commissioner Davis to adjourn. Upon
vote, the MOTION CARRIED UNANIMOUSLY.
Chairman Caster adjourned the meeting at 9:21 a.m.
Respectfully submitted,
Lucie F. Harrell
Clerk to the Board