HomeMy WebLinkAboutA003 - Council Action form dated March 23, 2004 ITEM #
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DATE 03/23/04
COUNCIL ACTION FORM
SUBJECT: TEXT AMENDMENTS TO THE FLOOD PLAIN REGULATIONS
BACKGROUND:
On August 22, 2000, City Council directed staff to develop the detailed mapping for the
floodway using a 1 .0-foot surcharge (one foot increase in flood waters within the "no-build"
floodway zone) and regulations requiring a building protection level standard that will be set
at three (3) feet above the 100-year base-flood elevation. Under City Council's direction,
staff has worked closely with Snyder and Associates, the Iowa Department of Natural
Resources (IDNR), the Federal Emergency Management Agency (FEMA), and citizen
groups in the city of Ames to develop a new flood plain map, draft regulations consistent
with the new map, and draft more stringent 100-year flood elevation standards. (See
attached Council Action Summary.)
The floodplain is divided into the floodway fringe and the floodway. The floodway is the
area reserved to carry the 100-year flood flows. The floodway fringe is that area in the
floodplain between the floodway line and the edge of the floodplain that is available for the
storage of water during a flood event. According to FEMA standards, the floodway fringe
may be filled with soil and used for development up to a point where the floodwaters are
"squeezed" (surcharged) and raised no more that one foot. As part of FEMA regulations,
the lowest floor for structures built in the floodway fringe must be constructed (elevated
with fill) one-foot higher than the expected water surface elevation during a 100-year flood
event. This regulation is considered the minimum "protection elevation." Local regulations
can be more restrictive with respect to the amount of floodwaters that can be raised in the
floodway, and the amount of "protection elevation" that must take place in the floodplain.
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action to establish This was done to
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that could be used for
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ground(Encroachment)
The 100-year flood plain is an area that is expected to have at least a 1% percent chance
of being flooded in any given year. Across the City of Ames, an elevation of floodwaters,
known as the base flood elevation, has been calculated for the flood plain. These areas are
shown on the Flood Insurance Rate Map (FIRM), which is printed by FEMA. A FIRM is
used to determine if a property is required to have flood insurance and establishes the
insurance premium. More importantly, it is used to assure that the City of Ames is properly
mitigating the negative impacts of flood events and protecting the life, safety, and property
of its citizens.
Currently, the City's legislated elevation requirement for development in the flood plain is
one (1) foot above the 100-year flood elevation shown on the existing FIRM, which was
placed into effect in 1981. Council's direction, however, was to raise the one (1) foot
protection to three (3) feet. This was done to mitigate flood damage of a 500-year flood
event, which would be similar to what the City of Ames experienced in 1993. The impacts
of a 500-year flood event are greater than a 100-year event. On the other hand, since the
City's existing floodway standard is a one-tenth (0.1 foot) rise in floodwater, the move to a
1-foot increase in floodwater in the floodway is actually less restrictive than what is
legislated today. This was directed by Council to assure the same area of land in the flood
plain today could remain conforming to the new FIRM and maintain its developable status.
Given the more accurate information known today, keeping the floodway at 0.1-foot would
mean a great majority of property elevated in the flood plain, such as property all along
South Duff Avenue, would be non-conforming.
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FEMA has indicated that it has completed a new FIRM that establishes the City's new one
(1)foot floodway standard. It takes into account most recent flood events and will take the
place of the existing FIRM on July 16, 2004. However, before the map goes into effect,
FEMA has informed the City that its flood plain ordinance must be amended to incorporate
City Council's direction for the less restrictive floodway and higher elevation standard.
Moreover, IDNR has informed the City that it must revise definitions for damage in the
City's Flood Plain Regulations so that they are consistent with federal law.
It is very important that the City of Ames maintains an accurate flood plain/floodway map
and complies with the regulations of the National Flood Insurance Program. The National
Flood Insurance Reform Act of 1994 requires that all lenders provide federally regulated
loans requiring flood insurance for all properties in the 100-year flood plain (as defined on
the FIRM). If a borrower is notified of the requirement and does not purchase the insurance
within 45 days, the lender must purchase the insurance on their behalf and can pass the
costs of obtaining the coverage on to the borrower. However, if the City of Ames does not
comply with the Federal regulations that establish the Flood Insurance Program and
related FIRM, property owners within the City will not be eligible for flood insurance. This
would increase property risk and complicate financing, and thus create many problems for
lenders, investors, developers, and property owners in the City of Ames.
Staff is proposing the following text amendments to the City's Flood Plain Regulations in
order for the City of Ames to meet the terms of the National Flood Insurance Program
(NFIP) under FEMA, comply with the prohibitions contained in Section 202(a)of the Flood
Disaster Protection Act of 1973, and carry out the direction set by City Council in August of
2000.
In order to comply with NFIP regulations and previous Council action, the City of Ames
must amend its existing Flood Plain Regulations as follows:
Sec. 9.1 (3)(a) Reserve sufficient flood plain area for the conveyance of flood flows
so that flood heights and velocities will not be increased by greater than one (1)
foot. [This means that floodwaters can raise one (1) foot in the floodway- the area
where water conveys and no building is allowed.]
Sec. 9.2 (2) Establishment of Official Flood Plain Zoning Map. The Flood Boundary
Map prepared as part of the Flood Insurance Study for the City of Ames, Iowa, in
1980, and subsequently thereafter during 2003 and 2004, as revised to conform to
the flood boundary map prepared as part of the Federal Emergency Management
Agency (FEMA) Flood Insurance Rate Map (FIRM), Federal Insurance
Administration, Revised Flood Insurance Study, Teagarden Area Watershed, are
hereby adopted by reference and declared to be the official Flood Plain Zoning
Map. The flood profiles and all explanatory material contained with the said flood
insurance studies and pertinent maps are also adopted by this reference and made
a part hereof. [This establishes the new FIRM map as the official flood map
document of the City of Ames.]
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Sec. 9.3 (1) Floodway (Overlay) District-The Floodway District shall be consistent
with the boundaries of the one (1) foot floodway as shown on the Flood Insurance
Rate Map (FIRM). [This means that the City of Ames will interpret the (1) foot
floodway as it is shown on the new FIRM map.]
9.5 (2)(b) Residential buildings. All new or substantially improved residential
structures shall have the lowest floor, including basements, elevated a minimum of
three (3) feet above the base flood elevation level. Construction shall be upon
compacted fill which shall, at all points, be no lower than three (3) feet above the
base flood elevation level and extend at such elevation at least 18 feet beyond the
limits of any structure erected thereon. Alternate methods of elevating (such as
piers) may be allowed, subject to favorable consideration by the Zoning Board of
Adjustment and issuance of a Conditional Use Permit, where existing topography,
street grades, or other factors preclude elevating by fill. In such cases, the methods
used must be adequate to support the structure, as well as withstand the various
forces and hazards associated with flooding.
[This establishes the higher elevation standard for residential buildings.]
All new residential buildings shall be provided with a means of access, which will be
passable by wheeled vehicles during the base flood elevation.
9.5 (2)(c) Non-residential buildings -- All new and substantially improved non-
residential buildings shall have the first floor (including basement) elevated a
minimum of three (3) feet above the base flood elevation level, or together with
attendant utility and sanitary systems, be flood proofed to such a level. When flood
proofing is utilized, a professional engineer registered in the State of Iowa shall
certify that the flood proofing methods used are adequate to withstand the flood
depths, pressures, velocities, impact and uplift forces and other factors associated
with the base flood elevation level, and that the structure, below the base flood
elevation level, is watertight with walls substantially impermeable to the passage of
water. A record of the certification indicating the specific elevation (in relation to
National Geodetic Vertical Datum)to which any structures are flood proofed shall be
maintained by the Zoning Administrator. [This establishes the higher elevation
standard for non-residential buildings.]
9.5 (2)(d)(ii). Factory-built homes including those placed in existing factory-built
home parks or subdivisions shall be elevated such that the permanent foundation of
the structure is a minimum of three (3) feet above the base flood elevation. [This
establishes the higher elevation standard for mobile and/or manufactured residential
buildings.]
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9.5 (2)(e)(i). All new and replacement sanitary sewage systems shall be designed to
minimize and eliminate infiltration of flood waters into the system, as well as the
discharge of effluent into flood waters. Wastewater treatment facilities shall be
provided with a level of flood protection equal to or greater than three (3)feet above
the base flood elevation. [This establishes the higher elevation standard for waste
treatment facilities.]
9.5 (2)(e)(iii). New or replacement water supply systems shall be designed to
minimize or eliminate infiltration of flood waters into the system. Water supply
treatment facilities shall be provided with a level of protection equal to or greater
than three (3) feet above the base flood elevation. [This establishes the higher
elevation standard for water supply facilities.]
9.5 (2)(f). Storage of materials and equipment that are flammable, explosive or
injurious to human, animal, or plant life is prohibited unless elevated a minimum of
three (3) feet above the base flood elevation level. Other material and equipment
must either be similarly elevated or(i) not be subject to major flood damage and be
anchored to prevent movement due to flood waters or(ii) be readily removable from
the area within the time available after flood warning. [This establishes the higher
elevation for equipment or materials that could hazardous during a flood event.]
9.5 (2)0)(v). The structure's service facilities such as electrical and heating
equipment shall be elevated or floodproofed to at least three (3)feet above the base
flood elevation level. [This establishes the higher elevation standard for utilities
within a structure.]
Sec. 9.8 (1). In The Floodway. When located in the Floodway, a structure, or the
use of a structure, or the use of land, which was lawful before July 16, 2004, but is
not in conformity with the provisions of this ordinance may be continued subject to
the following conditions: [This establishes the new FIRM map date as the base year
for non-conforming structures, thus creating consistency between the map and
following regulations.]
Sec. 9.8 (1)(d). Any nonconforming structure damaged by any origin to the extent
that the cost of restoring the structure to its before damaged condition would be less
than fifty (50%) percent of the market value of the structure before the damage
occurred, may be rebuilt provided such rebuilding does not increase the intensity of
use, as determined by the number of dwelling units (for residences), floor area, or
ground coverage (for nonresidential uses), does not increase the nonconformity,
complies with all other legal requirements, and is completed within 18 months from
the time of damage. [According to IDNR, this minor change must be made so that
the City's definition for damage condition is consistent with federal regulations.]
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Sec. 9.8 (2) In The Floodway Fringe. When located in the Floodway fringe, a
structure, use of a structure or the use of land, which was lawful before July 16,
2004, but is not in conformity with the provisions of this ordinance, may be
continued subject to the following conditions: [This establishes the new map date to
apply to the following conditions.]
Sec. 9.8 (2)(c). Any nonconforming structure damaged by any origin to the extent
that the cost of restoring the structure to its before damage condition would be less
than fifty (50%) percent of the market value of the structure before the damage
occurred may be rebuilt provided such rebuilding does not increase the intensity of
use, as determined by the number of dwelling units (for residences), floor area, or
ground coverage (for nonresidential uses), does not increase the nonconformity,
complies with all other legal requirements, and is completed within 18 months from
the time of damage. If the cumulative value of improvements and work to the
structure exceed the extent of 50% or more of the market value of the structure
before the damage occurred, the lowest floor must be elevated to three (3) feet
above the base flood elevation, or if the structure is a nonresidential structure, the
lowest floor may be flood proofed in accordance with the requirements of Section
9.5(2)of this ordinance. [Again, this makes the City's definition fordamage condition
consistent with federal regulations.]
Sec. 9.11 (7) Existing Construction. Structures for which the "start of construction"
commenced before the effective date of the initial FIRM (July 16, 2004). "Existing
construction" may also be referred to as "existing structures". [This defines new
construction and existing construction by the new map date.]
Sec. 9.11 (17) Floodway or Regulatory Floodway. The channel of the river or
watercourse and the adjacent land areas that must be reserved in order to
discharge the base flood without cumulatively increasing the water surface elevation
more than one (1) foot. [This means that the City of Ames will interpret the (1) foot
floodway, as it is shown on the new FIRM map, to convey flood waters.]
Sec. 9.11 (32) Substantial Improvement. Any repair, reconstruction, or improvement
of a structure, the cost of which equals or exceeds fifty(50%) percent of the market
value of the structure either(i) before the "start of construction" of the improvement,
or(ii) if the structure has been "substantially damaged"and is being restored, before
the damage occurred. The term does not, however, include any project for
improvement of a structure to comply with existing state or local health, sanitary, or
safety code specifications, which are solely necessary to assure safe conditions for
the existing use. The term also does not include any alteration of an "historic
structure", provided the alteration will not preclude the structure's designation as an
"historic structure". [This makes the City's definition for substantial improvement
consistent with federal regulations.]
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RECOMMENDATION OF THE PLANNING & ZONING COMMISSION:
The Planning & Zoning Commission recommended approval of the proposed text
amendments to the Flood Plain Regulations at their meeting of February 18, 2004.
ALTERNATIVES:
1. The City Council can approve the text amendments to the Flood Plain Ordinance
allowing for the City's compliance with FEMA regulations.
2. The City Council can deny the text amendments to the Flood Plain Ordinance, which
could mean that properties within the City of Ames will no longer be eligible for Flood
Insurance.
CITY MANAGER'S RECOMMENDED ACTION:
It is recommended that Alternative #1 be adopted, which will approve the proposed text
amendments to the Flood Plain Regulations to insure that properties within the City of
Ames remain in compliance with FEMA's flood insurance regulations.
COUNCIL ACTION:
Attachment
S:\Council Action Forms\Text Amendments\Flood Plain Ordinance Amendments-03-23-04.doc
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