Environmentally-Sensitive Areas - City
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Special Planning Regulations
ORDINANCE NO. 2003-__
WHEREAS:
The existing Subdivision
& Development Regulations requirements are not satisfying the community’s
needs. In order to provide for the
safe and orderly development of property, the maintenance of property values,
and the delivery of governmental services for the public’s protection and
safety, it is necessary to maintain the planning and zoning process with
periodic amendments in response to new and existing challenges.
The regulation requirements must be updated to reflect the current
professional thinking, engineering principles and best management practices to
address environmentally sensitive areas and sinkhole areas.
All new developments, including those that require substantial
renovations or expansions, within the urbanized area will be required to adhere
to the new requirements regarding environmentally sensitive areas.
Every time that a piece of land is developed, certain and expected
changes occur. Changes potentially
to the surface and sub-surface areas can be impacted.
The new regulations hope to reduce and offset those issues.
The intent of this proposed ordinance is to provide an
appropriate means to maintain and protect the integrity of environmentally
sensitive areas within our neighborhoods and the City of
NOW, THEREFORE, BE IT ORDAINED BY
THE COUNCIL FOR THE CITY OF
SECTION ONE: NEW PROVISIONS.
[Superseded language is shown as stricken.
All other language is new]
Article XII, 1200, G
G. MULTIPLE ENVIRONMENTALLY
SENSTIVE AREAS
During conceptual or preliminary plan or plan review, the Planning Commission
staff shall advise the developer of areas with a concentration of
environmentally sensitive resources or areas prone to hazards to human health
and safety, and the Planning Commission shall based upon findings of fact
regarding these areas, require analysis and implementation of measures to
mitigate impacts of development. Examples
include concentrations of sinkholes, cave areas, major rock formations, and
extremely steep slopes.
G.
ENVIRONMENTALLY
SENSITIVE AREAS
Environmentally sensitive areas are defined as those features located on
a property including sinkholes, cave areas, major rock formations and
outcroppings, springs, floodplains/floodways, landfills/refuse areas,.
Properties proposed for development that include environmentally
sensitive areas are encouraged to “design around” those areas and designate
them as “non-buildable” whenever possible in order to mitigate any potential
negative impacts on the area or within the development.
Due to the nature of portions of
Applicants for development proposals and/or their representatives shall
provide the Planning Commission staff with information regarding environmentally
sensitive areas and existing steep slope areas as follows:
a. (recommended) zone change application/concept
plan or master plan approval, including a map showing the specific location
of the of the environmentally sensitive feature and/or existing steep slope
areas.
b. (required) preliminary development plan or
subdivision plat approval. The
information shall include at a minimum a map showing the specific location of
the environmentally sensitive feature and/or existing steep slope areas that
will be further studied and examined. For
existing steep slopes, the map shall include the slope of the property at 100’
intervals across the slope; the Planning Commission Engineer may require
intervals less than 100’ if deemed necessary.
c. (required)
construction plan approval. The
information shall include specific location and extent or boundary(s) of the
environmentally sensitive feature and/or existing steep slope areas, method used
to determine the extent or boundary(s) of the feature and proposed remediation,
if applicable. Additional
information regarding protective measures during construction, as applicable,
shall be included as part of the construction plans.
i.
Examination of sinkholes, springs and other similar
features shall be completed by a licensed geo-technical engineer.
The Planning Commission shall require the geo-technical engineer to
submit a complete report of the findings, proposed remediation and verification
of remediation (i.e., certification of inspection of the remediation materials
and construction standards). Two (2)
copies of the analysis and study, including any remediation methods shall be
submitted to the Planning Commission Engineer for review and recordkeeping.
Verification and certification of any remediation methods is required
prior to final development plan or subdivision plat approval.
d. (required) final development plan or subdivision
plat approval. Environmentally
sensitive areas shall be shown on the final development plan or final
subdivision plat. Existing steep
slope areas must be shown or referenced on the final development plan or final
subdivision plat, if required by the Planning Commission or Planning Commission
Engineer. For sinkholes and other
similar features the final development plan or final subdivision plat shall
include approval and signature of Appendix III – Form M Sinkhole Certification
by the geo-technical engineer who performed the analysis of the area.
A note shall be placed on the final development plan or subdivision plat
indicating these areas, referencing the required study, including the date
performed.
For areas with a sinkhole, multiple sinkholes and/or a sinkhole cluster,
the following requirements shall apply:
Definitions:
Sinkhole: any closed depression formed by removal (typically
underground) of water, surficial soil, rock, or other material.
The existing of a sinkhole shall be as indicated by the closed depression
contour line(s) as shown on the USGS, KGS, GSCPC-GIS Section mapping or other
documents as approved by the Planning Commission Engineer and/or City Engineer,
as applicable. The actual limits may
however be determined by field measurements with concurrence of the Planning
Commission Engineer and/or City Engineer. Sinkholes
may be either circular in plan or irregular, depending upon structural control.
Immediate Sinkhole Drainage Area:
any area that contributes surface water directly to the sinkhole(s) not
including areas which contribute surface water indirectly to a sinkhole (via
streams or other means).
Sinkhole Cluster Area:
Any area that contributes surface water other than by way of a stream to
a sinkhole that is located in a group of two or more sinkholes clustering
together or in a line.
Sinkholes are natural depressions which drain a significant portion of
the mid- to lower areas of
Requirements:
1.
An applicant seeking subdivision plat or development
plan approval:
a. May divert enough of the sinkhole drainage area so
that the development of the remaining area does not increase the total quantity
of runoff into the sinkhole. For
approval of this type of proposal, the applicant shall provide for approval, a
study which must show that the development will not aggravate flooding on the
proposed development, adjacent properties or lands, or connected/adjacent
sinkhole clusters or systems.
b. Where the sinkhole outlet is offsite, either the
runoff leaving the subject property must be shown to be no greater in flow or in
quantity than that which is exerted before the development.
c. Sinkhole limits and non-buildable areas are to be
defined by a certified geologist and/or geotechnical engineer.
The sinkhole limits shall be identified as outlined in sections g.i., and
h.i., of this ordinance. The plats
and plans shall provide a reference to the required study detailing the method(s)
of the investigation used to define said limits.
d. Sinkhole limits and non-buildable areas are to be
identified on the preliminary or final development plan, preliminary or final
subdivision plat, and construction plans by shading or other means to clearly
identify those areas.
e. Post-developed discharges shall be treated prior to
draining into the sinkhole limits.
f. Structures located adjacent to the closed contour of
a sinkhole or adjacent to an immediate sinkhole drainage area shall not be
permitted to have a basement or first floor elevation lower than an elevation,
USGS Datum or other comparable source, to be determined on a case-by-case basis,
said elevation being at least one (1) foot above the 100 year 24-hour storm
event (maximum) assuming no outflow from the sinkhole.
Minimum Floor Elevations for such lots are to be referenced and shown on
the plat.
g. The applicant or applicant’s representative shall
verify any requirement of the Environmental Protection Agency (EPA) including
but not limited to ground water injection permit(s).
h. In the event that a sinkhole, immediate sinkhole
drainage area, sinkhole cluster area, or portions of such items are not shown on
the referenced maps and documentation but are determined or discovered during
the course of construction, the applicant shall:
i.
Notify the Planning Commission Engineer and City
Engineer, where applicable, immediately.
ii.
Shall provide all documentation, studies, and any
related information to the Planning Commission Engineer and City Engineer, where
applicable, as if the sinkhole, immediate sinkhole drainage area, sinkhole
cluster area, or portions of such items were identified prior to approval and
noted on the preliminary development plan and/or preliminary subdivision plat.
1. Upon determination of a sinkhole, immediate sinkhole
drainage area, sinkhole cluster area, or portions of such items, as noted in
section f.ii., any approvals of a preliminary or final development plan,
preliminary or final subdivision plat, or construction plans shall not
constitute automatic approval and shall not be grounds for the
continuation of any construction or development activity within the identified
area until such time as the required documentation, including detailed study,
have been reviewed and approved by the Planning Commission Engineer and City
Engineer, where applicable.
i. For residential areas (i.e., single family detached,
attached and multi-family developments):
i.
A sinkhole, immediate sinkhole drainage area,
sinkhole cluster area, or portions of such items shall be shown on the
preliminary and final development plan and/or preliminary and final subdivision
plat, and construction plans where they exist.
ii.
The sinkhole and its defined limits (i.e., closed
contours) shall be noted as “non-buildable” and may not be treated, filled,
or enclosed. No structure,
right-of-way, including roads (public or private) may be located within the
defined limits of a sinkhole.
1. For the purpose of calculating density for a
development, areas identified as sinkholes, including its defined limits, and
noted as non-buildable may be counted towards the total net acreage of the
development.
j.
For non-residential developments (i.e., professional
office, commercial, industrial):
i.
A sinkhole, immediate sinkhole drainage area,
sinkhole cluster area, or portions of such items shall be shown on the
preliminary and final development plan and/or preliminary and final subdivision
plat where they exist.
ii.
The sinkhole may be treated only upon review and
approval of a study certified by a licensed geotechnical engineer as to the
sinkhole limits, and proposed treatment/remediation methods.
Upon completion of the treatment, certification that the proposed work
was completed in accordance with the study and recommendations.
2.
Required Notes/Certifications
a. The following notes shall be placed on the
preliminary and final development plan, preliminary and final subdivision plat
and construction plans:
i.
Residential Uses:
1. “Any sinkhole related non-buildable area
identified here has been determined to be unsuitable for any construction
activity and no buildings, parking areas or other structures shall be permitted
within this area.”
2. “Residential structures located adjacent to the
closed contour of a sinkhole or adjacent to an immediate sinkhole drainage area
shall not be permitted to have a basement or first floor elevation lower than an
elevation, USGS Datum or other comparable source, to be determined on a
case-by-case basis, said elevation being at least two (2) foot above the 100
year 24-hour storm event (maximum) assuming no outflow from the sinkhole.
Minimum Floor Elevations for such lots are to be referenced and shown on
the plat.”
ii.
Non-Residential Uses:
1.
“Identified sinkhole area(s) were investigated in
the vicinity of ______________________. This
investigation was performed by ____________________ (geotechnical engineer) on
________________(date) and is on file with the offices of the Planning
Commission and City Engineer, where applicable.
The report details the activities used to explore these areas and any
recommendations regarding non-buildable areas (shown on the plat/plan) and
treatment areas suitable for construction.”
2. “Structures located adjacent to the closed contour
of a sinkhole or adjacent to an immediate sinkhole drainage area shall not be
permitted to have a basement or first floor elevation lower than an elevation,
USGS Datum or other comparable source, to be determined on a case-by-case basis,
said elevation being at least two (2) foot above the 100 year 24-hour storm
event (maximum) assuming no outflow from the sinkhole.
Minimum Floor Elevations for such lots are referenced and shown on the
plat.”
APPENDIX III - FORM M
CERTIFICATION
OF SINKHOLE NOTICE
I hereby certify that the sinkhole(s) on this
property pose no hazard to health or safety, that no excess stormwater shall be
directed to the sinkhole(s), and that all areas designated for load-bearing
construction are acceptable for such construction.
__________________________________
Registered Engineer
APPENDIX
III - FORM M (Amended)
CERTIFICATION OF ENVIRONMENTALLY SENSITIVE AREAS
NOTICE
I hereby certify that the environmentally sensitive
areas as defined in Article XII, Section 1200. G, have been identified and shown
on this plat. For areas including
sinkholes, springs and other related features, a study was performed including
an analysis of these features noting any non-buildable areas and, where
permitted, any remediation methods, techniques and materials that were
implemented and inspected in accordance with that analysis.
A copy of this analysis and related documents has been submitted to the
Planning Commission for their records.
__________________________________
SECTION TWO: EFFECTIVE DATE: This Ordinance shall take effect upon passage and publication.
The foregoing Ordinance was introduced and read for the first time at the
Council’s regular meeting
APPROVED BY:
_______________________________
EVERETTE VARNEY, MAYOR
ATTESTED BY:
________________________________
SUE LEWIS, CLERK