HomeMy WebLinkAboutG16-82 Ordinance No. G16-82
AN ORDINANCE
AMENDING CERTAIN PROVISIONS OF THE ELGIN MUNICIPAL CODE DEALING WITH
STORMWATER CONTROL
WHEREAS, uncontrolled development increases flooding hazards; and
WHEREAS, to protect life and property the City Council of the City
of Elgin has determined that it is necessary and desirable to control
certain developments in flood prone areas; and
WHEREAS, the City of Elgin must amend its flood control regulations
no later than March 1, 1982 to retain its participation in the Federal
Flood Insurance Program; and
WHEREAS, the City Council of the City of Elgin has determined that
it is urgent that this ordinance take effect immediately to ensure con-
tinued flood insurance coverage.
NOW, THEREFORE, BE IT ORDAINED BY THE CITY COUNCIL OF THE CITY OF
ELGIN, ILLINOIS:
Section 1. That Chapter 18.08 entitled "Definitions" be and is
hereby amended as follows:
"18.08 Definition
18.08.012 Base Flood.
"Base Flood" means the flood having a one-percent probability
of being equalled or exceeded in any given year. The base flood is
also known as the 100 year flood. The base flood elevation at any
location is as defined in Chapter 18.36.
18.08.014 Building.
"Building" as it relates to Chapter 18.36 means a structure
within a Special Flood Hazard Area that is principally above ground
and is enclosed by walls and a roof. The term includes a gas or
liquid storage tank in order that such tanks will be constructed to
the same flood damage protection standards. The term includes a
mobile home or prefabricated building which is affixed on a permanent
site and connected to the required utilities. The term does not
include recreational vehicles or travel trailers.
18.08.072 Development.
"Development" means any manmade change to real estate, including:
(i) construction, reconstruction, or placement of a building
or an addition to a building valued at more than $1,000;
(ii) installing a mobile home on a site or preparing a site
for a mobile home;
(iii) drilling, mining, installing utilities or facilities, con-
struction of roads, bridges or similar projects valued at
more than $1,000;
(iv) construction or erection of levees, walls, or fences;
(v) filling, dredging, grading, excavation, or other non-
agricultural alterations of the ground surface;
(vi) storage of materials; or
(vii) any other activity that might change the direction, height,
or velocity of flood or surface waters.
"Development" does not include:
(i) maintenance of existing buildings and facilities such as
re-roofing or re-surfacing roads;
(ii) repairs made to a damaged building that do not change the
building's exterior dimensions and that are valued at less
than 50% of the value of the building before the damage
occurred;
(iii) gardening, plowing, and similar agricultural practices that
do not involve filling, grading, or construction of levees;
or
(iv) agricultural development activities an farms including farm
residences as exempted by law.
18.08.100 Flood.
"Flood" means a general and temporary condition of inundation of
normally dry land areas from the overflow, the unusual and rapid
accumulation, or the runoff of surface waters from any source.
18.08.110 Flood Protection Elevation.
"FPE" or "Flood Protection Elevation" means the elevation of the
base flood plus one foot at any given location in the SFHA.
18.08.120 Floodway.
"Floodway" means that portion of the SFHA required to store and
convey the base flood. If not prohibited, building or placing obstruc-
tions in a floodway will increase flood damages to other properties.
18.08.262 Special Flood Hazard Area.
"SFHA" or "Special Flood Hazard Area" means those lands within the
jurisdiction of the city that are subject to inundation by the base
flood. The SFHA's of the city are generally identified as such on the
Flood Insurance Rate Maps (FIRM) prepared by the Federal Insurance
Administration and dated 4-1-82."
Section 2. That Chapter 18.36 entitled "Stormwater Control" of the
Elgin Municipal Code, 1976, as amended, be and is hereby repealed.
Section 3. That Chapter 18.36 be and is hereby added to the Elgin
eft Municipal Code, 1976, as amended, as follows:
"18.36 Stormwater Control
18.36.010 Applicability of Provisions.
A. This chapter supplements Titles 16 and 19 of this code and the
requirements contained in this chapter are in addition to the require-
ments of such regulations.
B. The provisions of this chapter regulate and restrict the follow-
ing:
1. The subdivision, layout, and improvement of land, including
drainage, underground utilities, and service facilities;
2. The excavating, filling, and grading of lots and other
parcels and areas subject to flooding; the storing of certain
materials thereon; stream and other stormwater runoff channels;
and detention areas;
3. The location, construction, and elevation of buildings
and other structures and parts and appurtenances thereof, and the
drainage of parking and other paved lots or areas;
4. The location and extent of areas along streams and water
channels which are subject to inundation and commonly known as
Special Flood Hazard Areas (SFHA).
18.36.020 Purpose.
It is recognized that uncontrolled development increases flooding
hazards and damage. The purposes of this chapter are, in addition to
those listed in 18.04.030, as follows:
A. to prevent unwise developments from increasing the flood or
drainage hazards to others;
B. to protect new buildings and major improvements to buildings
from flood damage;
C. to protect human life and health from the hazards of flooding;
D. to lessen the burden on the taxpayer for flood control projects,
repairs to flood damaged public facilities and utilities, and flood
rescue and relief operations;
E. to maintain property values and a stable tax base by minimizing
the potential for creating flood blight areas;
F. to make federally subsidized flood insurance available for
r property in the City; and
G. to provide for the orderly growth and development pursuant to
the City's comprehensive plan of an environment that is especially
sensitive to changes from human activity.
18.36.030 Base Flood Elevation.
This chapter's protection standard is the base flood according to
the best data available to the Illinois State Water Survey's Floodplain
Information Repository. Whenever a party disagrees with the best
available data, he may finance the detailed engineering study needed
to replace existing data with better data and submit it to the State
Water Survey.
A. The base flood elevation for the SFHAs of The Fox River and
Poplar, Willow and Tyler Creeks and Tyler Creek Tributary shall be as
delineated on the 100 year flood profiles in the Flood Insurance Study
of the City prepared by the Federal Insurance Administration and dated
9-1-81.
B. The base flood elevation for each of the remaining SFHAs
delineated as an "A Zone" on the Flood Insurance Rate Map shall be the
100 year flood depth calculated by the City Engineer or the State Water
Survey according to the formulas presented in Depth & Frequency of Floods
in Illinois published by the U.S. Geological Survey, 1976.
C. The degree of flood protection required by this chapter is con-
sidered reasonable for regulatory purposes and is based on available
information derived from engineering and scientific methods of study.
Larger floods may occur or flood heights may be increased by man-made or
natural causes. This chapter does not imply that development either
inside or outside of the SFHA will be free from flooding or damage.
This chapter does not create liability on the part of the City or any
officer or employee thereof for any flood damage that results from
reliance on this Chapter or any administrative decision made lawfully
thereunder.
18.36.040 Development and Improvement.
The preliminary plans of each proposed development shall provide
pertinent information on those areas abutting or adjacent to the project
which may affect or be affected by the development of the site. The
following information and data on existing conditions shall be furnished:
A. Contour Map. A two-foot-interval contour map of the land to
be developed or subdivided and such adjoining land whose topography may
affect the layout or drainage of the development or subdivision. On
such map shall be shown the following:
1. The flowlines of streams and other stormwater runoff
channels and the established high water elevation lines;
2. Normal boundary lines of lakes, ponds, swamps, and other
detention areas and the high water elevation boundary lines;
3. Field drain tiles including inlets and outfalls;
4. Storm, sanitary, and combined sewers including all
pertinent engineering data;
5. Septic tank systems including outlets;
6. Springs and wells;
7. Soil and water table conditions.
B. Undetermined Elevations. Where a limited number of high water
observations or determinations have been established on a stream,
channel, or lowland, the subdivider's engineer shall extend or project
the established high water elevation based on existing contours for the
area.
If high water elevations have not been determined and recorded, as
in a lowland, an elevation will be determined using past experience and
sound engineering judgment.
C. Comprehensive Drainage Plan. A comprehensive drainage plan
shall be designed and submitted and shall provide the following:
1. The location of watersheds, including their extent and
area, wholly or partially contained on the proposed development;
2. The existing and proposed storm sewer system, including
design calculations;
3. The locations within the development where storm sewer
backup, overflowing, or temporary street storage may occur;
4. Existing streams and stormwater runoff channels to be
maintained, enlarged, altered or eliminated; and new channels
to be constructed, their locations, cross sections and profiles;
5. Existing culverts and bridges, and the adequacy of those
waterway openings; and new culverts and bridges to be built,
their materials, elevations, waterway openings and basis of
design;
6. Existing detention areas to be maintained, enlarged, or
altered; and proposed detention areas;
7. The soil conditions within the proposed development;
8. A copy of the data and engineer's and owner's certificate
as required by state law according to Chapter 109 of the Illinois
Revised Statutes;
9. All appropriate design calculations and design criteria as
may be required by the city engineer.
18.36.050 Drainage Design Criteria.
The following design criteria shall govern the design of develop-
ments and subdivisions with respect to the drainage of stormwater runoff:
A. Generally. Streets, blocks, depth of lots, parks, and other
public grounds shall be located and laid out in such a manner as to
preserve and utilize natural streams, channels, and detention areas.
B. Channel Straightening. Sharply meandering streams or channels
may be partly straightened and minor changes made in other channels,
subject to approval of the city council, with the following provisions:
1. The dimensions of the stream or channel are maintained;
2. The volume of stormwater storage outside the channel is
not reduced;
3. The changes and channels comply with the provisions stated
in this chapter; and
4. Approval is obtained from all other regulating govern-
mental agencies.
C. Lesser Channel Locations. Generally acceptable locations of
the lesser stormwater runoff channels in the design of a subdivision
include the following:
1. In a depressed median of a boulevard or parkway, provided
the median is wide enough to permit flat side slopes;
2. Centered on the rear lot lines in a block, or entirely
within the rear yards of a single row of lots or parcels, provided
in either case the lots are deep enough to permit flat side slopes
along the lesser channel and a building site above the BFE plus
one foot exists on the front part of the lot.
In each of the foregoing cases, a drainage easement a minimum
distance of twenty-five feet from each side of the normal edge of the
watercourse, as determined by the city engineer, shall be provided and
shall conform substantially with the lines of said watercourse and shall
be shown on the plat. The easement shall permit necessary public channel
maintenance and improvement work and access of equipment; however, said
easement shall prohibit buildings and other obstructing structures
thereon by the owner.
D. Uppermost Reaches of Drainage Channels. The smaller uppermost
reaches of drainage channels and swales forming the natural drainage
system near the watershed divide may be relocated or eliminated and
incorporated into the planned system of storm sewers and/or open channels
upon demonstration that the system is adequate and can safely handle the
stormwater runoff following the heavier rainstorms to the satisfaction
of the city engineer.
E. Within-block Drainage. A continuous easement shall be provided
along all rear lot lines and drawn on the subdivision plat within which
utility lines and drainage may be located and maintained, but on which
no accessory buildings may be located or built. The utility-drainage
easement shall be at least ten feet wide, five feet on each lot.
F. Special Flood Hazard Area Lots. Land lying partially or totally
in the Base Flood Area may be laid out and planned as building lots or
parcels, provided a building site not lower than the base flood eleva-
tion plus one (1) foot:
1. exists on the high part of the lot or parcel; or
2. will be built up during execution of the subdivision improve-
ment plan through general excavation or filling; or
3. can be provided with escavation taken from within the area
of the lot or parcel.
G. Compensatory Storage. Such filling as may be required or permitted
in this title for a five (5) acre or more building site, or as may other-
wise be done in the base flood area, which eliminates space previously
available for storing and moving floodwater, shall be compensated for or
balanced by at least an equal volume of excavation in the base flood area
below the base flood elevation. In the case of streams and channels, such
excavation shall be made opposite, immediately adjacent or just upstream
to the area so filled. The compensatory storage area, when excavated and
constructed, shall drain freely and openly to the water course. Compensa-
tory storage shall not be required for developments under five (5) acres
in total size.
H. Street pavements Near Streams. The crown of street pavements
hereafter built adjoining or near streams, stormwater runoff channels,
or detention areas, shall not be lower than the base flood elevation
plus one (1) foot.
I. Detention Area Dams. Dams constructed to form floodwater deten-
tion areas, basins, or lakes shall be designed to maintain a temporary
stormwater storage pool following periods of runoff according to the
capacity of the downstream channel to carry the flow adequately.
J. Storm Sewers and Open Channels. The design of storm sewer
systems and open channels shall be based upon the "Rational Method"
using the equation Q=CiA, and the Manning Formula" using the equation
V=1.486R2/3xS1/2n.
The rainfall intensity, "i," shall be taken from the appropriate
curve for the Elgin area as published by the National Weather Service
or the State Water Survey.
The time of concentration, "t," to the first pickup point in a
system in residential areas shall be t-15 minutes as a minimum. In all
other areas, the initial time of concentration shall be determined by an
appropriate overland flow chart.
The following runoff coefficient, "c," shall be used in single-family
residential areas:
Average Lot Size
(In square feet) "c"
7,500 or less 0.40
7,501-10,000 0.35
Over 10,000 0.30
For multifamily residential, commercial, and industrial areas, the runoff
coefficient shall be as determined by acceptable design practices.
1. Storm sewers shall be designed to flow just full for the
five-year intensity-duration-frequency curve. The maximum allowable
width of the street gutter flow from the face of the curb shall be
limited to eight feet.
2. An overall drainage area layout plan showing the limits of
the contributing runoff area, broken down into areas contributing
to each drainage pickup point, shall be submitted with the paving
and drainage plans. Drainage design within the development shall
be adequate to handle the entire contributing watershed area, and
its existing, proposed and probable future development, and not the
area under submission only.
3. Whenever a storm drainage system for a proposed subdivision
or commercial development is designed to outlet into an existing
storm sewer system, the existing storm sewer system must be shown
by calculations to be adequate to carry the proposed additional
flow.
4. Storm drainage culverts shall be designed to conform to
the requirements of the State Department of Transportation.
5. Open channels shall be designed with a minimum freeboard of
two feet and a maximum velocity of fifteen feet per second.
6. The maximum allowable outlet velocity for storm sewers
without an outfall energy dissipator shall be twelve feet per
second.
7. Minimum pipe size for culverts and storm sewers shall be
twelve inches inside diameter with a minimum cleanout velocity of
two feet per second.
8. Manhole and/or catchbasin spacing between straight runs of
pipe shall be limited to a maximum spacing of three hundred feet
for sewers thirty-six inches or less in diameter; and a maximum
of five hundred feet for sewers over thirty-six inches in diameter.
18.36.060 Development Permit.
No person, firm, or corporation shall continence any development in the
SFHA without first obtaining a development permit from the city engineer.
The city engineer shall not issue a development permit if the proposed
development does not meet the requirements of this chapter.
A. Application for a development permit shall be submitted to the
city engineer and shall be accompanied by drawings of the site, drawn to
scale showing property line dimensions; and
1. existing grade elevations and all changes in grade resulting
from excavation or filling;
2. the direction of flow of surface drainage and flood flows;
3. the location of all watercourses and drainage facilities;
4. the location and dimensions of all buildings and additions
to buildings; and
5. the elevation of the lowest floor (including basement) of
all buildings subject to the requirements of section 18.36.070 of
this chapter.
B. Upon receipt of an application for a development permit, the
city engineer shall compare the elevation of the site to the base flood
elevation. Any development located on land higher than the base flood
elevation is not in the SFHA and therefore not subject to the require-
ments of this chapter.
C. The city engineer shall inform the applicant of any and all
other local, state, and federal permits that may be required for this
type of development activity. The development permit will only be
issued on the condition that the other specified permits are obtained.
The city engineer shall not approve a Certificate of Occupancy unless
all required permits have been obtained.
D. All new development proposals in the Special Flood Hazard
Areas shall be reviewed and approved by the city engineer. The city
engineer's review is to ensure the following:
1. new development will not change the flow of flood or other
surface drainage waters so that other properties become more
susceptible to damage;
2. new developments will not create special hazards or
nuisances when flooded; and
3. new buildings and major improvements to existing buildings
will not be subject to damage by the base flood.
E. No development in the SFHA shall create a damaging or potentially
damaging increase in flood heights or velocity.
1. For development proposals located in an identified floodway
or within a riverine SFHA where the floodway has not yet been
identified, the following rule shall apply: The city engineer
shall review the development plans to discern if
(a) a new obstruction to flood flows would be created;
(b) the project will involve a channel crossing such as
a bridge or pipeline; or
(c) the project will modify the shape of the channel.
If any of these three situations will result from the project, the
applicant shall be required to obtain a permit from the Illinois Depart-
ment of Transportation, Division of Water Resources, issued pursuant
to Ill. Rev. Stat. , Ch. 19, sec. 70. The city engineer shall not issue
a development permit unless the applicant has obtained either a Sec-
tion 70 permit or a "waiver of permit required" from the Division of
Water Resources.
2. For development proposals located in a flood fringe,
"AO Zone", or "AH Zone" identified as such on a SFHA map or in
a lakefront floodplain, ponding area, area of sheet flow, or
other SFHA not subject to overbank flooding from an identified
channel, the requirement of this subsection E.1 shall not apply.
F. No development in the SFHA shall include locating or storing
chemicals, explosives, bouyant materials, flammable liquids, pollutants,
or other hazardous or toxic materials below the FPE unless such materials
are stored in a storage tank or floodproofed building constructed accord-
ing to the requirements of this chapter.
G. New replacement sanitary sewer lines and on-site waste disposal
system may be permitted providing all manholes or other above ground
openings located below the FPE are watertight.
18.36.070 Building Regulations.
A. In addition to the damage prevention requirement of Section
18.36.060 all buildings to be located in the SFHA shall, except where
provided herein, be constructed at an elevation not lower than the base
flood elevation plus one (1) foot, otherwise known as the Flood Protec-
tion Elevation (FPE) and shall be protected from flood damage below the
FPE. This building protection requirement applies to the following
situations:
1. construction or placement of a new building valued at
more than $1,000;
2. improvements made to an existing building that increase the
first floor area by more than 50%;
3. reconstruction, repairs or improvements made to a damaged
building that are valued at or more than 50% of the value of the
building before the damage occurred; and
4. installing a mobile home on a new site or a new mobile home
on an existing site. This building protection requirement does
not apply to returning a mobile home to the same site it formerly
lawfully occupied.
B. This building protection requirement may be met by any one of the
following methods:
1. A building may be constructed on permanent land fill in
accordance with the following:
(a) The area to be filled shall be cleared of all standing
trees, brush, down timber, trash, and other growth or objects
unsuitable for use as foundation material.
(b) The fill shall be placed in layers no greater than 1
foot deep before compaction.
(c) The surface of the fill shall be at or above the FPE.
The fill shall extend at least 10 feet beyond the foundation
of the building before sloping below the FPE.
(d) The fill shall be protected against erosion and scour
during flooding by vegetation cover, rip rap, or bulkheading.
If vegetative cover is used, the slopes shall be no steeper
than 3 horizontal to 1 vertical.
(e) The fill shall not adversely affect the flow of
surface drainage from or onto neighboring properties.
(f) The city engineer shall maintain a record of the "as
built" elevation of the lowest floor of the building.
2. A building may be elevated in accordance with the following:
(a) The building or improvements shall be elevated on
stilts, piles, walls, crawl space, or other foundation that
is permanently open to flood waters and not subject to damage
by hydrostatic pressures.
(b) The foundation and supporting members shall be
anchored, shaped and aligned so as to minimize exposure to
known hydrodynamic forces such as current, waves, and floating
debris. A11 mobile homes to be placed within Zone A on the
Flood Insurance Rate Map (FIRM) shall be anchored to resist
flotation, collapse, or lateral movement by providing over-
the-top and frame ties to ground anchors. Specific require-
ments shall be that
1. over-the-top ties be provided at each of the four
corners of the mobile home, with two additional ties per
side at intermediate locations and mobile homes less than
50 feet long requiring one additional tie per side;
2. frame ties to be provided at each corner of the
home with five additional ties per side at intermediate
points and mobile homes less than 50 feet long requiring
four additional ties per side;
3. all components of the anchoring system be capable
of carrying a force of 4,800 pounds; and
4. any additions to the mobile home be similarly
anchored.
(c) All areas below the FPE shall be constructed of
materials resistant to flood damage. The bottom of the joists
of the lowest floor and all utility meters shall be located at
or above the FPE.
(d) The city engineer shall maintain a record of the "as
built" elevation of the lowest floor.
(e) No area below the FPE shall be used for storage of items
or materials subject to flood damage unless such items or
materials are declared "property not covered" by a Standard
Flood Insurance Policy of the National Flood Insurance Program.
(f) Any future alteration of the area below the FPE that
violates the requirements of this Section 2 shall be deemed a
violation of this chapter. The city engineer shall inform the
applicant that any such alteration is considered a willful act
to increase flood damages and therefore will cause coverage by a
Standard Flood Insurance Policy to be suspended.
r (g) No mobile home may be placed on a new site located within
an identified floodway.
3. A non-residential building may be floodproofed in
accordance with the following:
(a) A registered Professional Engineer shall certify
that the building has been designed so that below the FPE,
the structure and attendant utility facilities are water-tight
and capable of resisting the affects of the base flood. The
building design shall take into account flood velocities, dura-
tion, rate of rise, hydrostatic and hydrodynamic forces, the
effects of buoyancy, and impacts from debris or ice.
(b) Floodproofing measures shall be operable without human
intervention and without an outside source of electricity.
(c) The city engineer shall maintain the engineer's
certificate and a record of the "as built" elevation to which
the building was floodproofed.
C. The city council shall take into account flood hazards to the
extent that they are known, in all official actions related to land manage-
ment, use and development.
1. The city council shall not approve any annexation agreement
or plat of subdivision located outside the corporate limits unless
such agreement or plat is in accordance with the provisions of this
chapter. The city engineer shall obtain the best available SFHA
maps and data for the unincorporated areas.
2. New subdivisions, mobile home parks, and planned unit develop-
ments (PUDs) shall meet the requirements of this chapter. Plats or
plans for new subdivisions, mobile home parks, and planned unit
developments (PUDs) shall include a signed statement by a Registered
Professional Engineer that the plat or plans account for changes
in the drainage of surface waters in accordance with the Plat Act
(Ill. Rev. Stat. , 1979, Ch. 109, par. 2).
3. Plats or plans for new subdivisions, mobile home parks, and
planned unit developments (PUDs) shall display the following flood
data:
(a) the boundary of the SFHA;
(b) the boundary of the floodway, if shown on available
SFHA maps;
(c) easements of lands dedicated to the City for access
for channel maintenance purposes; and
(d) the FPE for each building site. Where the Base Flood
Elevation is not available from an existing study filed with
the Illinois State Water Survey, the applicant shall be
responsible for calculating the FPE and submitting it to the
State Water Survey for review and approval as best available
elevation data.
4. Plans for the development activities to be undertaken by
the City in the SFHA shall be reviewed by the city engineer to
ensure that they comply with this chapter. Except as exempted by
law, no other local government shall commence any development
activity in the SFHA without first obtaining a development permit
from the city engineer.
5. The Department of Community Development shall take the
following into consideration when preparing or revising the compre-
hensive plan, community development program, housing assistance
plan, and other land use or development programs:
(a) preserving SFHA land for open space uses such as
farming or recreation;
(b) acquiring and removing frequently flooded buildings;
(c) prohibiting hospitals, water treatment plants,
natural gas storage and other critical or especially hazard-
ous facilities from locating in the SFHA;
(d) identifying the elevations of the Base Flood and
past floods at entrances to public buildings, on street signs,
or other prominent locations; and
(e) other flood hazard mitigation or floodplain management
activities that could help accomplish the purposes of this
chapter.
18.36.080 Stormwater Detention Areas--Purpose and Findings.
A. It is recognized that many of the receiving streams and lowland
areas within the City do not have the capacity to receive and convey the
increased stormwater runoff resulting from urbanization occurring in many
areas. These receiving streams or lowlands are subject to periodic
inundation which results in a growing rate of property damage.
B. It is the intent of this section to require developers to participate
in providing detention area storage to eliminate excessive runoff during
heavy storm periods. . Other control methods which would be acceptable to
regulate the rate of stormwater discharge include detention on flat roofs,
parking lots, streets, lawns, underground storage, and oversized storm
sewers with restricted outlets.
C. It is recognized that in order to better serve the long-range
interests of the City, comprehensive basin-wide planning for stormwater
control shall be followed as determined by the city engineer. This com-
prehensive drainage plan may require that a single large detention area
serve several parcels as determined by the city engineer. Comprehensive
basin-wide drainage planning is far more beneficial than individual onsite
detention, although onsite detention does provide protection and is
acceptable for compliance with this chapter.
18.36.090 Stormwater Detention Areas--Requirements.
Pursuant to the provisions of this chapter, no final plat shall be '"
approved unless detention of stormwater runoff is provided as set forth
in the following criteria:
A. A combination of storage and controlled release of storm water
runoff is required for all commercial developments exceeding two acres in
area; and for all residential developments exceeding five acres in area.
However, a residential development of five acres or less must have an
adequate outlet as determined by the city engineer. If the outlet is not
adequate, then detention, as determined by the city engineer, will be
required to store that portion of the runoff exceeding the outlet
capacity.
B. The release rate of stormwater from all developments requiring
detention shall not exceed the stormwater runoff rate from the area in
its natural undeveloped state. The city will accept a release rate of not
greater than that calculated from a storm of five-year frequency with a
runoff coefficient of 0.15.
C. Drainage systems shall have adequate capacity to bypass through
the development the flow from all upstream areas for a storm of five-year
frequency assuming that the land is in a fully developed state under
present zoning or zoning proposed under a comprehensive plan. The bypass
flow rate shall be computed utilizing a runoff coefficient of not less
than 0.45. An allowance will be made for upstream detention when such
upstream detention and release rate has previously been approved by the
City and that evidence of its construction can be shown.
D. The detention storage volume to be provided will be calculated
on the basis of the one hundred-year storm, for any and all durations,
from the fully developed drainage area tributary to the reservoir, less
that volume discharged during that same duration at the approved release
rate.
E. Sample calculations reflecting the provisions of this section
will be furnished by the city engineer upon request."
Section 4. That Chapter 18.48 entitled " Variations and Exceptions"
be and is hereby amended to read as follows:
"18.48 Variations and Exceptions.
18.48.010 Generally.
The land use and subdivision hearing examiner may approve variations
from these requirements in specific cases which do not affect the general
plan or the intent of this title. Such decisions may be appealed in
writing to the land use committee for review.
A. No variance shall be granted for any construction or development
located wholly or partially within a SFHA unless the applicant demonstrates
that:
1. the development activity cannot be located outside the SFHA;
2. a substantial economic hardship would result if the
variance were not granted;
eft
3. the relief requested is the minimum necessary;
4. there will be no additional threat to public health or
safety or creation of a nuisance;
5. there will be no additional public expense for flood
protection, rescue or relief operations, policing, or repairs
to roads, utilities, or other public facilities; and
6. the provisions of subsection 18.36.060(C) of this
chapter can still be met.
B. The city engineer shall notify an applicant in writing that a
variance from the requirements of Chapter 18.36 that would lessen the
degree of protection to a building will:
1. result in increased premium rates for flood insurance
up to amounts as high as $25 for $100 of insurance coverage;
2. increase the risks to life and property; and
3. require that the applicant proceed with knowledge of
these risks and that he will acknowledge in writing that he
assumes the risk and liability.
C. A variance from the requirements of Chapter 18.36 may be granted
to permit a "wet floodproofed" building, that is: a building to be
intentionally flooded during a flood, provided:
1. No part of such a building below the FPE may be subject to
flood damage.
2. The variance shall be conditioned on the contents being:
(a) of materials resistant to flood damage; or
(b) ' items declared "property not covered" by a Standard
Flood Insurance Policy of the National Flood Insurance Program;
or
(c) readily moveable to a place of protection during a flood
provided there will be personnel available and adequate warning.
3. Any future alteration of the area below the FPE that violates
the conditions of the variance shall be deemed a violation of this
chapter. The city engineer shall inform the applicant that any such
alteration is considered a willful act to increase flood damages and
therefore will cause coverage by a Standard Flood Insurance Policy to
be suspended.
D. Variances requested in connection with restoration of a site or
building documented as worthy of preservation by the Illinois Department of
Conservation may be granted using criteria more permissive than the require-
ments of Chapter 18.36."
Section 5. That Chapter 18.52 entitled "Violations and Penalty" be
and is hereby amended to read as follows:
"18.52 Violation and Penalty
18.52.010 Designated.
The city engineer may determine upon due investigation that a viola-
tion of the minimum standards of this chapter exist and after such owner
fails after ten days notice to correct his property, the City may make
application to the circuit court for an injunction requiring conformance
with this chapter or make such other order as the court sees necessary to
secure compliance with the chapter. In addition to the foregoing, any
person who violates this chapter shall upon conviction thereof be fined
not less than twenty-five dollars ($25.00) nor more than five-hundred
($500.00). A separate offense shall be deemed committed upon each day
during or on which a violation occurs or continues. Failure to comply
with the requirements of a permit or conditions of a variance resolution
shall be deemed to be a violation of this chapter. Nothing herein shall
prevent the City from taking such other lawful action to prevent or remedy
any violations. All costs connected therewith shall accrue to the person
or persons responsible."
Section 6. That the City Clerk shall cause this ordinance to be published
in pamphlet form and same shall be incorporated into the Elgin Municipal Code,
as amended.
Section 7. That the provisions of this ordinance shall take effect upon ""
passage.
s/ Richard L. Verbic
Richard L. Verbic, Mayor
Presented: February 24, 1 982
Passed: February 24, 1982
Vote: Yeas 7 Nays 0
Recorded:
Published:
Attest:
s/ Marie Yearman
Marie Yearman, City Clerk