The purpose of this Article is to establish standards for the use of protected open spaces, the management of the City's floodplains and floodways (including the prevention of flood damage), and for the environmental impacts of the City's land uses (e.g., noise, vibration, air quality, water quality, and glare), in order to ensure that the City continues to provide a desirable environment for residences, recreation, education, culture, commerce, and industry.

A.

Uses in Open Space. The standards of Article 3, Development Standards, or Division 2-4, Limited and Conditional Use Standards, may require identification of land areas on a parcel proposed for development that will be set aside as permanent open space. It is the intent of the City Council that such areas be available for multiple uses that are consistent with their open space designations and resource management objectives. Division 7-2, Use of Designated Open Space, establishes the uses that are permitted in designated open space and the standards that apply to those uses.

B.

Floodplain Management and Flood Damage Prevention.Division 7-3, Floodplain Management and Flood Damage Prevention, sets out the technical standards for development within the floodplain areas of the City.

C.

Environmental Quality.Division 7-4, Environmental Quality, sets out the standards for hours of construction noise, ground vibration, emissions of air pollutants, discharge of water pollutants, and creation of glare. In some cases these provisions are cross-references to standards that are enforced by other levels of government. Such references do not waive requirements for compliance with any other applicable state or federal standards that are not listed.

A.

General. This Section lists the uses that are allowed in the designated open spaces that are required elsewhere in this LDC. If the use is located within a floodplain, then the standards of Section 12-7-202, Use of Floodplains, also apply.

B.

Agricultural Uses.

1.

Agriculture and Nursery. Where agricultural and outdoor nursery uses are allowed by Section 12-2-304, Industrial, Agricultural, and Special Uses, the area of land put to agricultural and outdoor nursery uses is counted as open space. In other districts, noncommercial production of crops (e.g., orchards or garden plots that are an amenity to development) is allowed in designated open space areas.

C.

Recreation Uses.

1.

Ball fields, golf courses, nature areas, picnic areas, play courts, and trails are allowed in designated open space areas.

2.

Nature centers are allowed in designated open space areas, provided that associated buildings and parking occupy not more than 20 percent of the designated open space.

3.

Pools are allowed in designated open space areas, provided that if a pool house is present, it is less than 1,500 square feet in floor area.

D.

Public Facilities.

1.

Advanced ecologically engineered wastewater treatment systems.

2.

Stormwater management facilities and utility lines are allowed in designated open space areas.

3.

Renewable energy generation facilities that comply with Section 12-3-607, Renewable Energy Systems, or Section 12-3-805, Renewable Energy Systems, as applicable, are allowed in designated open space areas that are not floodplains.

E.

Temporary Uses. Public interest or special events are allowed in designated open space areas, subject to the requirements of Section 12-2-502, Community and Neighborhood Events.

A.

Generally.

1.

This Section sets out the permitted uses and restrictions of land that is within the floodplain, and performance standards for the construction and operation of the uses.

2.

Land within the floodplain may be used for other purposes so long as the primary conveyance and storage function of the floodplain is preserved, the use is not a detriment to water quality, and the use is consistent with the LDC.

B.

Permitted Uses of Floodplains. The City has determined that the following uses and improvements may be considered for approval within a floodplain if it is determined that the proposed use or improvement is in conformance with the floodplain management regulations, floodplain management goals, and is otherwise consistent with the zoning district standards of the LDC. It must be demonstrated that none of the conditions in subsection D., below, will occur as a result of the proposed use or improvement.

1.

Agricultural Uses. The following agricultural uses are allowed in the floodplain:

a.

Agriculture (including crop production, livestock grazing, and fish hatcheries) and nursery, where allowed in the applicable zoning district.

b.

Noncommercial production of crops (e.g., orchards or garden plots that are an amenity to development)

2.

Recreation Uses. The following recreation uses are allowed in the floodplain:

a.

Nature areas, picnic areas, and trails.

b.

Ball fields.

c.

Golf courses, provided that:

i.

The applicant provides a management plan that demonstrates that downstream water quality will not be adversely affected by fertilizers and pesticides associated with the use; and

ii.

Pedestrian or golf cart trails and bridges are designed in accordance with the requirements of the SEMSWA Stormwater Management Manual.

d.

Play courts/Playground Equipment.

e.

Trails and Paths open to the general public.

3.

Public Facilities. The following public facilities are allowed in the floodplain.

a.

Works for watershed protection and similar uses.

b.

Detention and water quality facilities associated with approved master drainage plans.

c.

Local streets only if the street depth criteria in the Stormwater Management Manual and Roadway Design & Construction Standards Manual are not exceeded and alternative access outside of the SFHA is available.

d.

Underground utilities as long as adequate cover exists to protect the utilities.

e.

Parking for park and public facilities.

4.

Landscaping. Landscaping in allowed provided that all applicable floodplain requirements set forth in this Article are met.

C.

Non-Permitted Uses of the floodplain.

1.

Use Factors. In general any use that has potential for the following to occur is prohibited in the floodplain:

a.

Obstruction of the flood water flow so that the SFHA is altered in elevation in excess of the allowable criteria (unless approved through a floodplain modification study).

b.

Reduction in the carrying capacity of the channel (unless approved through a floodplain modification study).

c.

Potential for material, equipment, or facilities to become dislodged or displaced and to be deposited downstream causing culvert or bridge blockage, channel degradation, or damages to other properties.

d.

Potential for negatively impacting water quality.

2.

Prohibited Uses. The City has determined that the following uses are prohibited within the floodplain:

a.

All structures including residential, non-residential, recreational.

b.

Fill in the floodplain for the purpose of obtaining a CLOMR-F/LOMR-F for future site development.

c.

New construction of critical facilities.

d.

Addition to existing structures.

e.

Fencing, including solid or perforated wood, split rail, chain link, stone, brick and/or other materials.

f.

New construction of landscaping walls or structural walls that extend or flatten land that result in floodplain encroachment.

g.

New construction of streets.

h.

Storage or processing of materials, which are buoyant, flammable, explosive, or could cause injury to humans, animals, or plants.

i.

Storage, processing of materials, or any other activity that may have an adverse impact on water quality.

j.

Permanent toilet facilities.

k.

New construction of structures, ponds, or appurtenances related to water and wastewater treatment facilities.

l.

Parking lots not associated with an approved floodplain use.

m.

Detention or water quality ponds not part of a regional or approved drainage master plan.

n.

Camping.

3.

Storage of Materials. Storage of hazardous or floatable materials in the floodplain is prohibited. These materials represent a significant potential public health, environmental or safety risk. Floatable materials can also become lodged in culverts, bridges and channels resulting in increased damages resulting from increased flood depths or diversion of flood waters. Notwithstanding the foregoing, temporary storage of construction-related vehicles and materials may be permitted by the Floodplain Administrator, depending upon location and type of material storage.

D.

Performance Standards for Use of Floodplains.

1.

No floodplain use shall adversely affect the efficiency of or unduly restrict the capacity of the channels or floodplains of the mainstream or any tributaries to the mainstream, drainage ditches, or any other drainage facilities or systems.

2.

No structure (temporary or permanent), fill, (including fill for roads and levees), deposits, obstruction, storage of materials, or other floodplain uses which, acting alone or in combination with existing or future floodplain uses, shall be permitted that adversely affect the efficiency or the capacity of the floodplain, or adversely affects the storage capacity of the floodplain. Impervious surfaces in the floodplain shall be minimized. Proposed impervious surfaces in the floodplain are subject to approval by the SEMSWA with respect to generated storm water runoff.

3.

All uses of the floodplain shall comply with applicable floodplain management regulations contained in Division 7-3, Floodplain Management and Flood Damage Prevention, as may be amended from time to time, and the SEMSWA Stormwater Management Manual.

E.

Uses Not Listed. Uses not specifically listed above may be permitted if, in the opinion of the Director, they are similar in character to permitted uses in this district, and are in conformance with the intent of this district. Uses not specifically prohibited in this section should not be construed as allowed by exclusion.

(Ord. 2024-O-05 §§28, 29)

A.

Findings of Fact.

1.

The flood hazard areas of the City are subject to periodic water inundation that can result in loss of life and property, health and safety hazards, disruption of commerce and governmental services, extraordinary public expenditures for flood protection and relief, and impairment of the tax base, all of which adversely affect the public health, safety and general welfare.

2.

The flood losses are caused by the cumulative effect of obstructions in special flood hazard areas which increase flood heights and velocities, and when inadequately anchored, damage uses in other areas. Uses that are inadequately flood-proofed, elevated or otherwise protected from flood damage also contribute to the flood loss.

B.

Statement of Purpose. It is the purpose of this Division 7-3, Floodplain Management and Flood Damage Prevention, to promote the public health, safety, and general welfare, and to lessen public and private losses due to flood conditions to specific areas by provisions designed:

1.

To protect human life and health;

2.

To reduce expenditure of public money for costly flood control projects;

3.

To reduce the need for rescue and relief efforts associated with flooding and generally undertaken at the expense of the general public;

4.

To reduce prolonged business interruptions;

5.

To reduce damage to public facilities and utilities such as water and gas mains, electric, telephone and sewer lines, streets and bridges located in special flood hazard areas;

6.

To help maintain a stable tax base by providing for the sound use and development of special flood hazard areas so as to reduce future flood blight areas;

7.

To provide a means to respond to requests from potential developers for information supporting a decision regarding whether property is in a special flood hazard area;

8.

To ensure that potential buyers are notified that property is in a special flood hazard area; and

9.

To provide that those who occupy the special flood hazard areas assume responsibility for their actions.

C.

Applicability.

1.

These Regulations shall apply uniformly to all special flood hazard areas within the jurisdiction of the City of Centennial. No structure or land shall hereafter be constructed, located, extended, have fill placed upon, converted or materially altered without full compliance with the terms of this Division and other applicable regulations regarding floodplain management and flood damage prevention.

2.

This Division is not intended to repeal, abrogate, or impair any existing easements, covenants, or deed restrictions. However, where this Division and another ordinance, easement, covenant, or deed restriction that are enforceable by the City conflict or overlap, whichever imposes the more stringent restrictions shall prevail.

D.

Methods of Reducing Flood Losses. In order to accomplish its purposes, this Division, in conjunction with Division 7-2, Uses of Designated Open Space, Section 12-11-402, Stormwater Management Manual, the required floodplain review procedures in Section 12-14-205, Required Floodplain Determination, and the required review and permit procedures in Section 12-14-206, Floodplain Development Permit, includes methods and provisions for:

1.

Restricting or prohibiting uses which are dangerous to health, safety, and property due to flood water or erosion hazards, or which result in damaging increases in erosion or in flood heights or velocities;

2.

Requiring that development vulnerable to floods, including facilities which serve such development, be protected against flood damage at the time of initial construction;

3.

Requiring that substantial improvement or improvements from substantial damage to any existing structure in the floodplain be removed from the floodway and have two (2) feet of freeboard without increasing the footprint of the structure.

4.

Controlling the alteration of natural floodplains, stream channels, and natural protective barriers, which help accommodate or channel flood waters;

5.

Controlling filling, grading, dredging, and other development which may increase flood damage;

6.

Preventing or regulating the construction of flood barriers which will unnaturally divert flood waters or which may increase flood hazards in other areas;

7.

Preventing all new construction or installation of residential or non-residential structures in any floodplain;

8.

Restricting encroachments, including fill, new construction, and other development in any floodplain unless a technical evaluation demonstrates that the encroachments will not result in an increase (no rise) in flood levels during the occurrence of the base flood, or a FEMA-approved CLOMR or City-approved Floodplain Modification Study is provided;

9.

Requiring a minimum clearance, or freeboard of two (2) feet, be provided between the 100-year base flood elevation and the structure's lowest floor and other applicable facilities which may be impacted by or are adjacent to the floodplain. Freeboard is required to allow for uncertainty in the floodplain modeling, changes to the drainageway (i.e., increased invert due to sedimentation), and to provide an additional factor of safety for structures and facilities which would result in damages or hazards during inundation; and

10.

In some cases, consideration should be given to providing protection from flooding events that are produced by storm events in excess of the 100-year storm event including access routes that are critical for the protection of public health, safety, and welfare, or where flooding in excess of the 100-year storm event could result in loss of life, significant damage to utilities and infrastructure, or result in hazardous materials being transported in flood waters. In general, placement of new critical facilities within the 500-year floodplain is discouraged.

Definitions provided for terms in this Division are found in Division 16-2, General Definitions.

A.

Lands to which this Section Applies. This Section shall apply to all floodplains within the jurisdiction of the City.

B.

Basis for Establishment of Special Flood Hazard Areas.

1.

The special flood hazard areas identified by the Federal Emergency Management Agency in its "Flood Insurance Rate Map (FIRM)" and "Flood Insurance Study (FIS)" for Arapahoe County, Colorado and Incorporated Areas dated December 17, 2010; February 17, 2017; September 4, 2020; and, April 11 2024, and any letters of map revision (LOMR) thereto, are adopted by reference and declared to be a part of this LDC. In the event of conflict between the December 17, 2010 FIRM and FIS, the February 17, 2017 FIRM and FIS, September 4, 2020 FIRM and FIS and the April 11, 2024 FIRM and FIS, the April 11, 2024 FIRM and FIS shall govern.

2.

The FIRM and FIS are on file at the Centennial Civic Center, 13133 East Arapahoe Road, Centennial, Colorado 80112 and at the Southeast Metro Stormwater Authority, 7437 South Fairplay Street, Centennial, Colorado 80112.

3.

The Flood Hazard Area Delineation ("FHAD") studies produced by the Urban Drainage and Flood Control District ("UDFCD"), as may be amended and updated from time to time, are adopted by reference and are declared to be a part of these regulations. Also, the Floodplain Administrator shall notify adjacent communities, the District, and the Colorado Water Conservation Board prior to any alteration or relocation of a water course and must submit evidence of such notification to the Federal Emergency Management Agency ("FEMA").

4.

The Colorado Water Conservation Board ("CWCB") is the State Coordinating Agency of the National Flood Insurance Program. The Flood Protection Program of the CWCB assists in the review and approval of all reports and maps that are normally used by local governments for regulatory, floodplain administration, and insurance purposes. Technical information used for regulation of flood prone areas must be designated and approved by the CWCB before the information is used for floodplain management purposes.

5.

Other sources, such as CLOMRs, LOMRs, Preliminary FIRM and FIS, drainage studies, and master development plans, as deemed appropriate by the Floodplain Administrator.

C.

Compliance. As of November 10, 2013, no structure or land shall be constructed, located, extended, converted, or altered without full compliance with the terms of Article 7, Open Space, Floodplain Management, and Environmental Quality, and other applicable regulations. Uses or structures established as of November 10, 2013 that were unlawfully established or constructed are not legally nonconforming and therefore subject to all provisions of this Article.

D.

Abrogation and Greater Restrictions. Article 7, Open Space, Floodplain Management, and Environmental Quality, is not intended to repeal, abrogate, or impair any existing easements, covenants, or deed restrictions. However, where Article 7, Open Space, Floodplain Management, and Environmental Quality, and another Section, easement, covenant, or deed restriction enforceable by the City conflict or overlap, whichever imposes the more stringent restrictions shall prevail.

(Ord. 2024-O-01 § 2)

A.

Generally. In all floodplains, the standards of this Section are required to be met.

B.

Proposed Structures in the Floodplain.

1.

New Construction. New construction or installation of residential or non-residential structures shall be prohibited.

2.

Other Development. All other development in floodplains shall be prohibited unless shown to the satisfaction of the Floodplain Administrator through a floodplain development permit that the proposed development (as defined in Article 16) does not adversely affect the efficiency of, or unduly restrict the capacity of, the channels or floodplains of the mainstream or any tributaries to the mainstream, drainage ditches, or any other drainage facilities or systems.

3.

Conditions of Approval of Floodplain Development Permit. The Floodplain Administrator may impose conditions of approval on Floodplain Development Permits to achieve compliance with the provision for flood hazard reduction standards, which conditions may include modification of proposed systems and facilities and imposition of operational controls and limitations on periods and conditions of use and operation. Additionally, a map revision process may be required prior to permit approval.

C.

Existing Structures in Floodplains.

1.

Use of Floodplains. All uses of property in a floodplain shall comply with applicable floodplain regulations contained in this LDC. It is the intent of the City that no new construction of structures be constructed in a floodplain, and that all such existing legal nonconforming structures either be removed upon obsolescence or be improved to meet substantial improvement criteria set forth in Subsection C(2), Substantial Improvements, below.

2.

Substantial Improvements. Substantial improvements (including improvements due to damage) of existing structures are permitted in the flood fringe but not in the floodway, provided such substantial improvements meet the freeboard criteria in Subsection C(3), Construction Standards and do not increase the footprint of the structure.

3.

Construction Standards. All improvements to existing structures in the floodplain shall adhere to the following:

a.

Residential Construction. Substantial improvements to any residential structure in the floodplain shall have the lowest floor elevated to or above the minimum freeboard requirement of two (2) feet or highest adjacent grade plus two (2) feet above the depth in shallow flooding areas (AO and AH Zones). A registered Colorado Professional Engineer, architect, or land surveyor shall submit certification (Elevation Certificate) to the Floodplain Administrator and that the standard of Section 12-14-206, Floodplain Development Permit, have been satisfied.

b.

Nonresidential Construction. Substantial improvement of any commercial, industrial or other nonresidential structure shall either:

i.

Meet the minimum freeboard of two (2) feet or highest adjacent grade plus two (2) feet above the depth in shallow flooding areas (AO and AH Zones). A registered Colorado Professional Engineer, architect, or land surveyor shall submit certification (Elevation Certificate) to the Floodplain Administrator and that the standard of Section 12-14-206, Floodplain Development Permit, have been satisfied; or

ii.

Together with attendant utility and sanitary facilities, shall:

a.

Be flood-proofed so that below the base flood level plus two (2) feet of freeboard the structure is watertight with walls substantially impermeable to the passage of water;

b.

Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy;

c.

Be certified by a registered Colorado Professional Engineer or architect that the design and methods of construction are in accordance with accepted standards of practice for meeting the applicable provisions of this Section. The Floodplain Administrator shall keep records of these certifications (Floodproofing Certification) pursuant to Section 12-13-103, Floodplain Administrator; and

d.

In shallow flooding areas (Zone AH or AO) have adequate drainage paths around the structure to guide flood waters around and away from the structure.

c.

Construction Materials and Methods.

i.

All substantial and non-substantial improvements shall be constructed with materials and utility equipment that are resistant to flood damage.

ii.

All substantial and non-substantial improvements shall be constructed using methods and practices that minimize flood damage.

iii.

All substantial and non-substantial improvements shall be constructed with electrical, heating, ventilation, plumbing, and air conditioning equipment and other service facilities that are designed and/or located so as to prevent water from entering or accumulating with the components during conditions of flooding.

d.

Openings in enclosures below the Lowest Floor. For all substantial improvements, fully enclosed areas below the lowest floor that are subject to flooding shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwater. Designs for meeting this requirement must either be certified by a registered Colorado Professional Engineer or architect or must meet or exceed the following minimum criteria:

i.

A minimum of two openings having a total net area of not less than one (1) square inch for every square foot of enclosed area subject to flooding shall be provided;

ii.

The bottom of all openings shall be no higher than one (1) foot above grade;

iii.

Openings may be equipped with screens, louvers, or other coverings or devices provided that they permit the automatic entry and exit of floodwater.

4.

Anchoring.

a.

Foundations shall be designed or engineered to be anchored to resist flotation, collapse or lateral movement and be capable of resisting the hydrostatic and hydrodynamic loads. Methods of anchoring may include, but are not limited to, use of over-the-top or frame ties to ground anchors. This requirement is in addition to any applicable State and/or local anchoring requirements for resisting wind forces. In addition, the following specific requirements shall be met:

i.

Over-the-top ties must be provided at each of the four (4) corners of the manufactured home, with two (2) additional ties per side at intermediate locations, with manufactured homes less than fifty (50) feet long requiring one additional tie per side;

ii.

Frame ties must be provided at each corner of the home, with five (5) additional ties per side at intermediate points, with manufactured homes less than fifty (50) feet long requiring four (4) additional ties per side;

iii.

All components of the anchoring system must be capable of carrying a force of four thousand eight hundred (4,800) pounds; and

D.

Critical Facilities.

1.

Protection for critical facilities.

a.

New construction of critical facilities shall be located outside the floodplain.

b.

Change of use of a structure to a critical facility or substantial improvement of an existing critical facility in the floodplain shall include elevation of the lowest floor or flood-proofing of the structure (non-residential construction), together with attendant utility and sanitary facilities, to at least two (2) feet above the Base Flood Elevation. Additionally, no increase in the footprint of the existing facility shall be allowed.

2.

Ingress and egress for critical facilities. New construction of critical facilities, change of use of a structure to a critical facility, or substantial improvements of existing critical facilities shall, when practicable as determined by the City, have continuous non-inundated access (ingress and egress for evacuation and emergency services) during a 100-year flood event.

E.

Freeboard. A minimum clearance, or freeboard shall, be provided between the floodplain or adjacent to the floodplain or shallow flooding area and structures and other applicable facilities which may be impacted by the base flood. Freeboard is required to allow for uncertainty in the floodplain modeling, changes to drainageway (i.e., increased invert due to sedimentation), upstream development and to provide an additional factor of safety (buffer) for structures and facilities which would experience damages or hazards during inundation.

1.

The City requires a minimum of two (2) feet of freeboard between the 100-year water surface elevation and the lowest floor elevation of all substantially improved structures in the floodplain or adjacent properties to the floodplain.

2.

For facilities which are not structures such as roadways, utility cabinets, parks and trail improvements, a minimum of one (1) foot of freeboard may be required where there are detrimental impacts to the floodplain as determined by the Floodplain Administrator.

3.

Shallow flooding areas (AO and AH Zones) or adjacent properties shall have the lowest floor elevated two (2) feet above the highest adjacent grade or two (2) feet above the depth number specified in feet on the community's FIRM, assuming a depth of at least two (2) feet if no depth is specified on the FIRM.

F.

Utilities.

1.

All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of floodwaters into the system.

2.

New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of floodwaters into the systems and discharge from the systems into floodwaters.

3.

On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding.

G.

Floodways. Construction in the floodway as allowed per Section 12-7-202 C and D, Performance Standards for Use of Floodplains, shall be subject to the following requirements:

1.

Development is prohibited, including fill, new construction, and other development unless certification by a registered Colorado Professional Engineer is provided demonstrating that encroachment shall not result in any increase in flood levels (no rise) during the occurrence of the base flood, or otherwise alter the floodway in a manner which will constrict the channel or increase erosion potential unless a FEMA approved CLOMR that addresses the 44 CFR Part 65, Section 12 requirements or City approved Floodplain Modification Study are obtained.

2.

If the requirements of subsection G.1. above are satisfied, all new construction shall comply with all applicable flood hazard reduction provisions of this Section.

3.

For all floodplains and special flood hazard areas that do not have a regulatory floodway designated, development is prohibited unless there is a City approved Floodplain Modification Study or FEMA approved CLOMR.

4.

For LOMRs on special flood hazard areas where the effective FIRM shows a one (1.0) foot floodway, the one-half (0.5) foot floodway will not be required until the entire drainageway is remapped at which time the revised map will show a one-half (0.5) foot floodway.

H.

Flood Fringe Development. Encroachment in the flood fringe is only allowed for approved uses listed in Section 12-7-202, Use of Floodplains. When considering requests involving flood fringe development, the Floodplain Administrator shall consider, at a minimum, the following:

1.

Flood fringe filling. Filling will not be allowed for purposes of obtaining a CLOMR-F/LOMR-F or similar (i.e., as a way to remove a property from the floodplain) for future site development.

2.

Impacts to Adjacent Properties. If the development creates a rise in the Base Flood Elevation on properties other than that of the applicant and the applicant has obtained a City approved Floodplain Modification Study or FEMA approved CLOMR, the applicant will be required to obtain floodplain easements for the additional floodplain property.

3.

Channel Hydraulics and Design. If the development creates a significantly narrow channel, with steep side slopes and undesirable velocities, the City may require mitigating channel improvements, or not support the flood fringe development.

4.

Channel Aesthetics and Land Use. If the encroachment significantly impacts the aesthetics of the natural drainageway, and the resulting channel improvements create a drainageway that is not deemed compatible with the surrounding land uses, the City may not support the flood fringe development.

5.

Flood Fringe and Floodway Volume. If the development does not maintain equivalent flood fringe and floodway volumes, the City may not support the proposal.

6.

Cumulative Effect. The one-half (0.5) foot floodway is cumulative, and therefore all proposals considering development in the fringe, must consider the total cumulative impact, based on historical and future encroachment on both sides of the drainageway.

7.

Floodplain Modification Study or CLOMR. When flood fringe development is allowed, a floodplain modification study, or CLOMR consistent with the scope of work shall be provided.

8.

LOMR-F. A Floodplain Development Permit shall not be issued for the construction of a new structure, redevelopment (substantial improvements) of an existing structure or addition to an existing structure on a property removed from the floodplain by issuance of a FEMA Letter of Map Revision Based on Fill (LOMR-F), where the lowest floor elevation is placed below the Base Flood Elevation (BFE). For this situation, the lowest floor elevation must be two (2) feet above the BFE (freeboard) that existed prior to the placement of fill, to receive an approved Floodplain Development Permit.

I.

Subdivision Proposals. The following shall apply to all subdivision applications on land in or adjacent to floodplain areas.

1.

Minimize Flood Damage. All subdivision applications including the placement of manufactured home parks and subdivisions shall be consistent with the need to minimize flood damage.

2.

Floodplain Development Permit. All subdivision applications shall meet Floodplain Development Permit requirement of Section 12-14-206, Floodplain Development Permit.

3.

Protection of Utilities. All subdivision applications shall have public utilities and facilities such as sewer, gas, electrical and water systems located and constructed to minimize flood damage.

4.

Drainage. All subdivisions shall have adequate drainage provided to reduce exposure to flood hazards.

5.

Base Flood. The applicant shall be responsible for generating any base flood elevation data and survey data requested by the Floodplain Administrator relating to the site and proposed development. In cases where there is conflicting base flood elevation data, the data which is most protective of flood hazard areas and which restricts development will be used.

6.

Floodplain Areas. Floodplain boundaries must be considered in subdivision layout, where applicable. When the floodplain boundary accurately represents the proposed floodplain limits, lots can be platted as discussed in the previous sections. There are many cases, however, where the SFHA or mapped floodplain is much wider than the actual or proposed floodplain. This situation frequently arises in locations where the SFHA or mapped floodplain was delineated using approximate methods or where improvements are proposed to confine the floodplain. In this case, platted lots must be outside of the SFHA or mapped floodplain or the actual floodplain, whichever is more restrictive.

7.

Proposed Subdivision Lots Removed from or adjacent to Floodplains. This subsection 7 applies to subdivisions where any proposed lots are required to be removed from the floodplain or where any proposed lots are adjacent to the floodplain. In either such case, an approved CLOMR or Floodplain Modification Study will be required prior to the City's approval of a final plat. A plat restriction shall prohibit the issuance of building permits on the affected lots until a LOMR or LOMA has been issued by FEMA and the appeal period has expired or a similar map change process has been approved by the City for non-FEMA mapped floodplains.

8.

Freeboard. Basements in structures on lots directly adjacent to a floodplain will be required to have two (2) feet of freeboard above the BFE.

J.

Recreational Vehicles. Recreational vehicles as defined in Article 16 of the LDC shall be allowed to park in floodplains for purposes of loading or unloading, preparing for service or preparing for storage not exceeding forty-eight (48) hours.

A.

Interpretation. In the interpretation and application of this Division, all provisions shall be:

1.

Considered as minimum requirements;

2.

Liberally construed in favor of the governing body; and

3.

Deemed neither to limit nor repeal any other powers granted under State Statutes.

B.

Warning and Disclaimer of Liability. The degree of flood protection required by this LDC is considered reasonable for regulatory purposes and is based on scientific and engineering considerations. Larger floods can and will occur on rare occasion. Flood heights may be increased by man-made or natural causes. This LDC does not imply that land outside the special flood hazard areas or uses permitted within such areas will be free from flooding or flood damages. This LDC shall not create liability on the part of the City, any officer or employee thereof, or the Federal Emergency Management Agency, for any flood damages that result from reliance on this LDC or any administrative decision lawfully made thereunder.

In order to control noise levels, construction activities within 300 feet of residential uses shall not take place between the hours of 7:00 p.m. and 7:00 a.m. The Director may authorize construction activities during the hours of 7:00 p.m. to 7:00 a.m. for good cause shown, including, but not limited to, minimizing peak hour traffic disruptions and performing emergency repairs.

A.

Generally. Ground vibration can be a nuisance to abutting property, regardless of whether it is perceptible to people without instruments. The performance standards of this Section are intended to limit the negative effects of ground vibration in the City.

B.

Measurement. For the purposes of this Section, vibration is measured as "vibration decibels," or VdB, which are calculated as: VdB = 20 × log10(v/(1 × 10-6 in./sec.)), where "v" is the rms velocity amplitude, calculated as the average of the squared amplitude of the vibration, measured in inches per second.

C.

Standards. The standards of Table 12-7-402, Vibration Standards, shall be met at the property line, except as provided in subsection E., below.

D.

Off-Site Boundaries. Where the lot or parcel proposed for development is located near a different zoning district, but does not include a property line that is also a district boundary line, the standards of this Section shall be met at the district boundary line in accordance with subsection C, above, as well.

E.

Exceptions. The following are excepted from these standards:

1.

Vibrations emanating from construction activities between the hours of 7:00 a.m. and 7:00 p.m. that are temporary in nature, and necessary for the construction activity.

2.

Transient vibrations of moving vehicles, such as trucks and automobiles or trains.

3.

Extraction activities may be granted limited exceptions to impact vibration standards during the conditional use approval process, and those conditions shall be controlling.

F.

Measurement. An operator trained to measure vibrations shall make all such measurements and shall submit and certify them to the City.

(Ord. 2024-O-13 §55)

A.

Generally. Air quality shall be maintained according to state and federal standards. Demonstrations of compliance shall be provided as required by this Section.

B.

Emissions. Applicants for approval of uses that will emit air pollutants that are subject to regulation pursuant to the federal Clean Air Act and the Colorado Air Pollution Prevention and Control Act (Section 25-7-101, et seq., Colorado Revised Statutes), shall demonstrate compliance with those laws.

C.

Control of Wind Blown Dust. Land owners shall control wind blown dust as required by Section 35-72-102, Colorado Revised Statutes, Duty of Landowner - Liability for Damage.

A.

Stormwater Management. Measures to protect water quality and to manage the quantity and velocity of stormwater runoff shall be implemented pursuant to the standards set out in the SEMSWA Stormwater Management Manual. See Section 12-11-402, Stormwater Management Manual.

B.

Grading, Erosion, and Sediment Control. Measures to protect water quality during construction and for land disturbance activities shall be implemented pursuant to the standards set out in the SEMSWA Grading, Erosion and Sediment Control Manual. See Section 12-11-403, Grading, Erosion and Sediment Control Manual.

A.

Glare from Use. Glare from any process (such as or similar to arc welding or acetylene torch cutting) which emits harmful ultraviolet rays shall be performed in such a manner as not to be seen from any point beyond the property line, and as not to create a public nuisance or hazard along lot lines.

B.

Glare from Buildings and Structures. Buildings and structures (including signs) shall be designed and oriented to avoid glare that materially interferes with the safe operation of streets for motor vehicles and bicycles.