(A)

Structures Prohibited in Floodway and Drainage Connections Any construction that diminishes the functional floodway capacity is prohibited. The criteria for determining such prohibition will be that criteria declared by FEMA.

(B)

Permissible Uses in Floodplains

(1)

General farming, pasture, outdoor plant nurseries, horticulture, forestry, wildlife sanctuary and other related uses.

(2)

Ground level loading areas, parking areas.

(3)

Lawns, gardens, play areas.

(4)

Golf courses, tennis courts, driving ranges, parks, trails, open space, and other similar private and public recreational uses.

(5)

Single-family homes, with special permission of City Council, and constructed in accordance with Construction within Floodways and Floodplains Restricted.

(6)

The storage of hazardous materials or hazardous waste within a floodplain is expressly prohibited.

(C)

Construction within Floodways and Floodplains Restricted

(1)

Development Order or Permit Requirements. No development order or permit may be issued for any development within a flood plain until the approving authority has reviewed the plans for any such development to assure that:

(a)

The proposed development is consistent with the need to minimize flood damage; and

(b)

All public facilities such as sewer, electrical, reclaimed water and potable water systems are located and constructed to minimize or eliminate flood damage; and

(c)

Adequate drainage is provided to minimize or reduce exposure to flood hazards; and

(d)

The approval includes a condition that all necessary development orders or permits from those agencies from which approval is required by federal or state law will be obtained prior to construction.

(2)

New Construction Prohibited in Floodway. No building may be constructed and no improvement of an existing building may take place within any floodway.

(3)

Construction in Floodplain. No new building may be constructed and no substantial improvement of a residential building may take place within any floodplain unless the lowest floor (including basement) is elevated no lower than one (1) foot above the base flood elevation. For non-residential construction, flood proofing may be used in lieu of elevation if a registered professional engineer or architect shall certify that the construction or substantial improvement has been designed to withstand the flood depths, pressure, velocities, impact, and uplift forces associated with the base flood at the location of the building and that the walls below the base flood level are substantially impermeable to the passage of water.

(4)

Building Permit Criteria. No building permit may be issued for any new construction or substantial improvements within a floodplain until the permit-issuing authority has reviewed the plans to assure that the construction shall be:

(a)

Designed (or modified) and adequately anchored to prevent flotation collapse, or lateral movement of the structure.

(b)

Constructed with materials and utility equipment resistant to flood damage.

5)

Dredging and Filling. Dredging and filling of lands within a floodway is prohibited unless an overriding public health, safety, and welfare concern is demonstrated or such action is necessary for the reasonable use of the property. No encroachment of floodplain shall be allowed unless fully mitigated.

(6)

Final Plat Approval. Final plat approval for any subdivision containing land that lies within a floodway or floodplain may not be given unless the plat shows the boundary of the floodway or floodplain and contains in clearly discernible print the following statement: Use of land within a floodway or floodplain is substantially restricted by the City Code of Ordinances.

(D)

Water Supply and Sanitary Sewer Systems in Floodways Whenever any portion of a proposed development is located within a floodway or floodplain, the developer must provide certification by a registered certified engineer that:

(1)

Such water supply system is designed to minimize or eliminate infiltration of flood waters into it.

(2)

Such sanitary sewer system is designed to eliminate infiltration of flood waters into it and discharge from it into flood waters.

(3)

Any on-site sewage disposal system is located to avoid impairment to it or contamination from it during flooding.

(4)

Design of water and wastewater systems shall conform to the Engineering Standards Manual.

(A)

Natural Drainage System To the extent practicable, all development shall conform to the natural contours of the land and natural and pre-existing manmade drainage ways shall remain undisturbed. Isolated vegetated wetlands which are not invaded with exotic plant species shall be maintained and incorporated into stormwater management facilities to the maximum extent possible.

(B)

Stormwater Management

(1)

Drainage Systems for Each Phase. The drainage system for any phase of development shall be capable of standing on its own if subsequent areas planned for development are not completed.

(2)

Existing Off-Site Runoff. The drainage system for each development shall make provisions to adequately convey existing contributing off-site runoff either through or around the development.

(3)

Post Development Run-off Equal to Pre-Development Runoff. The storage and controlled release or retention on-site and infiltration into the ground of the stormwater run-off from any development will be required so that the peak run-off will not be greater than it was prior to such development. Refer to Engineering Standards Manual for specific design criteria.

(4)

Upland/Upstream Property Owner. An upstream property owner may only use his/her property in a reasonable manner and may convey stormwaters downstream and increase the velocity, volume, or loads of its flow in a reasonable manner; provided, however; that the direction of flow may not be modified unless downstream compensating storage is provided.

(5)

Downland/Downstream Property Owner. A downstream property owner may not dam, block, impede, or obstruct stormwater flow from a lawful upstream property use.

(6)

Relationship to Other Stormwater Management Requirements. In addition to meeting the requirements of the LDC, the design and performance of all stormwater management systems shall comply with applicable state regulations (F.S. Ch. 373 to be carried out in a manner consistent with Chapter 62-40 of the Florida Administrative Code (FAC) and be permitted by the St. Johns River Water Management District pursuant to Chapter 40C-4 FAC. In all cases, the strictest of the applicable standards shall apply.

(7)

Level of Service Standard. The level of service standards established in the Comprehensive Plan must be met by all new developments and redevelopment projects.

(8)

Design Standards. Specific design standards are included in the Engineering Standards Manual.

(C)

Water Quality

(1)

State Water Quality Standards. Permitted rates and volumes, if applicable of stormwater runoff, whether discharged into natural or artificial watercourses, shall meet State water quality standards.

(2)

Impact on Wetlands. No site alteration shall cause siltation of wetlands, pollution of downstream wetlands, or reduce the natural retention or filtering capabilities of wetlands.

(3)

Health Hazard. No site alteration shall allow surface water to become a health hazard.

(D)

Recharge

(1)

Minimize Runoff. Developments shall maximize the infiltration of natural rainfall into the soil and minimize direct overland runoff into adjoining streets and water courses.

(2)

Encourage Infiltration. Run-off from driveways, roofs, or other impervious areas should be diverted so as to flow over grassed areas prior to flowing into any drainage system whenever possible.

(3)

Development in Recharge Areas. Development in areas determined to have prime recharge as refined through specific technical information provided to the City by the applicant, shall meet the least restrictive of the following standards:

(a)

Post-development rates and volumes must be at least equal to pre-development rates and volumes; or

(b)

Post-development rates and volumes must achieve at least seventy (70) percent infiltration to the aquifer of all on-site stormwater.

(c)

Impervious surfaces shall not exceed fifty (50) percent of the total site area in such areas.

(4)

The Following Uses Are Prohibited in Recharge Areas.

(a)

Junk yards containing materials which may contaminate the aquifer,

(b)

Outside storage of hazardous or toxic wastes, and

(c)

Tank farms and other petroleum products storage.

(E)

Easements The City may require drainage easements to provide for the protection and legal maintenance of drainage systems not within a right-of-way.

(1)

Easements Required. Drainage easements may be required over any portion of a drainage system not within a right-of-way at the City's sole discretion and necessary for the functioning of the system.

(2)

Unobstructed Access. Access easements shall be utilized to provide unobstructed access for maintenance equipment from a street or right-of-way. Adequate maintenance access shall be provided for all drainage systems (retention, detention basins, etc.).

(3)

Easement Widths. Minimum easement widths are included in the Engineering Standards Manual.

(F)

Erosion and Sediment Control All construction projects as part of the development order application must submit an erosion and sediment control plan to insure that the following issues are addressed:

(1)

All developments must be constructed and operated in a manner which does not contribute to soil erosion or sedimentation damage.

(2)

Sediment contamination measures shall be implemented where a potential for sediment transfer to water bodies or floodplains exists.

(3)

Seeding, mulching, sodding and/or other acceptable methods shall be performed as required to prevent undue erosion during all construction activities. The developer shall be required to keep accumulations of sand and earth out of the curb and gutter. Temporary siltation basins may be required during construction.

(4)

No site alteration shall cause sedimentation of wetlands, pollution of downstream wetlands, or reduce the natural retention or filtering capabilities of wetlands unless permitted otherwise.

(5)

Intermittent watercourses, such as swales, must be vegetated to prevent erosion.

(6)

Artificial watercourses and water bodies must be designed so that the velocity of flow is low enough to prevent erosion and so that aeration and circulation are optimized.

(7)

Specific design and construction standards are included in the Engineering Standards Manual.

Standards regarding stormwater management and drainage facilities are listed below. In addition, specific construction standards can be found in the Engineering Standards Manual.

(A)

Performance Standards All development must be designed, constructed and maintained to meet the following minimum performance standards:

(1)

The stormwater management systems preferred for new development shall be consistent with best management practices.

(2)

The stormwater requirements of this section shall be achieved through the retention or detention of stormwater run-off in surface facilities, such as grassed swales (where soils are conducive), or retention and/or detention ponds.

(3)

Detention volume shall be provided so that the post-development peak rate of discharge shall not exceed the pre-development peak rate of discharge for the twenty-five-year/twenty-four-hour design storm event, with a rainfall depth of 8.6 inches.

(4)

The proposed development activity shall not violate the water quality standards as set forth in Chapter 62-40, Florida Administrative Code.

(B)

Stormwater Management General Technical Standards

(1)

It is the responsibility of the applicant to submit sufficient information for the building official and public works director or their designees, to determine whether the requirements of this stormwater management code are being met. The public works department may from time to time issue design guidelines that are to be followed in meeting the requirements of this Code.

(2)

Submittal information should detail elevations or contours, direction of flow, and other grading or fill information. Submittals should also detail the computations and calculations utilized to demonstrate satisfaction of the retention requirements. Submittals should also detail the type of soil conditions present and the depth to the water table. A soils report and/or survey may be required to verify the conditions represented on the plan.

(3)

It shall be the duty of the property owner to provide proper maintenance of the stormwater management system so that the system continues to meet the requirements of this code. The City shall have the power to inspect stormwater management systems and facilities and to require such maintenance, repair and replacement of facilities as necessary. Necessary maintenance and repair shall be made within a time period not to exceed thirty (30) days after notification by the City of the problem and required corrective action.

(C)

Design Standards Specific stormwater management design and construction standards are provided in the Engineering Standards Manual.

(D)

Surface Stormwater System Standards

(1)

Surface stormwater systems utilized to accomplish the stormwater retention and percolation requirements shall be designed so as to be readily accessible from rights-of-way, parking lots, court yards or other open areas so that maintenance and clean-out of these areas can be easily accomplished.

(2)

Spillways or other entrance channels to retention areas shall be designed to prevent the flushing of these retention areas by heavy rains.

(3)

Retention areas shall be designed and function such that all retained water is removed after three (3) days. If this is not accomplished by percolation and/or evaporation, the retention area must be improved to include an underdrain system or other bottom materials to achieve this requirement.

(E)

Underground Stormwater System Standards

(1)

Underground stormwater seepage systems may be permitted provided those systems are designed for the prevention of clogging by fine material and for ease of cleaning with conventional sewer cleaning equipment. This may include, but not necessarily be limited to, the wrapping of the perforated pipe and seepage trench with an appropriate fabric and the provision of sufficient clean-outs for the system.

(2)

Underground stormwater seepage systems shall be designed so as to accept the peak runoff from a storm of five-year frequency and one (1) inch of concentration in addition to retaining the required rate and volume, if applicable, of stormwater runoff as set forth previously in this Code.

(3)

Pipes utilized shall be of material acceptable to the City Engineer or Public Works Director. The minimum diameter of any pipe utilized for any portion of an enclosed storm drainage system shall be fifteen (15) inches.

(F)

Design Storm Standards The specific minimum design storm standards are identified in the Engineering Standards Manual.

(G)

Drainage Area Geometry The specific drainage area geometry requirements are listed in the Engineering Standards Manual.

(H)

Material and Design Specifications The specific material and design specifications are provided in the Engineering Standards Manual.

(I)

Inlets and Structures The specific inlets and structures specifications are identified in the Engineering Standards Manual.

(A)

Basic Principles Erosion control measures shall comply with the provisions of F.S. § 403.0885, and applicable rules of the Florida Administrative Code pursuant to the Florida Department of Environmental Protection's National Pollutant Discharge Elimination System Stormwater Regulatory Program. There are five (5) basic principles of reducing erosion and sedimentation from developing areas.

(1)

Plan the Development to Fit the Site.

(a)

Slope length and gradient are key elements in determining the volume and velocity of runoff and its associated erosion. As both slope length and steepness increase, the rate of runoff increases and the potential for erosion is magnified. Where possible, steep slopes should be left undisturbed. Long steep slopes should be reduced by benching, terracing or construction of diversions.

(b)

Soils which contain a high proportion of silt and very fine sand are generally the most erodible. Soil erodibility is decreased as the percentage of clay or organic matter increases. Well-drained soils, generally gravel-sand mixtures, are the least erodible.

(c)

Natural vegetative cover is extremely important in controlling erosion because it:

(i)

Shields the soil surface from the impact of falling rain;

(ii)

Increases infiltration of water into the soil;

(iii)

Increases evapotranspiration of water into the air;

(iv)

Reduces the velocity of runoff; and

(v)

Holds soil particles in place as well as filtering surface runoff.

(2)

Expose the Smallest Practical Area of Land for the Shortest Possible Time. Plan the phases of development so that only areas which are actively being developed are exposed. All other areas should have a good cover of temporary or permanent vegetation or mulch. Grading should be completed as soon as possible after it is begun and stabilization measures shall be initiated as soon as practicable, but in no case no more than seven (7) days. Cut slopes and fill slopes should be revegetated as soon as they are brought to proper grade. Minimizing grading of large or critical areas during the season of maximum erosion potential (May 1 to September 30) reduces the risk of erosion.

(3)

Apply Soil Erosion Practices to Prevent On-Site Damage. These practices control erosion on a site and prevent excessive sediment from being produced. Keep the soil covered as much as possible with temporary or permanent vegetation or with various mulch or netting materials. Special grading methods such as roughening a slope on the contour or tracking with a cleated dozer are highly effective. Other practices, such as berms or diversion structures, control the surface runoff.

(4)

Apply Sediment Control Practices as a Perimeter Protection to Prevent Off-Site Damage. Once sediment is produced, practices such as diversion ditches, sediment traps, vegetative filters and sediment basins can be used to prevent the sediment from getting off- site. Generally, sediment can be retained by two (2) methods:

(a)

Filtering runoff; and

(b)

Impounding the sediment-laden runoff for a period of time so that the soil particles settle out.

(5)

Implement a Thorough Maintenance and Follow-Up Operation. This principle is vital to the success of the preceding principles. A site cannot be effectively protected without thorough, periodic checks of the erosion and sediment control practices. Proper installation and maintenance of practices is a must if they are to effectively perform their functions. An improperly installed or maintained practice is both expensive and functionless. A routine "end of day check" to make sure all control practices are working properly is an easy and quick way to maintain the site.

(B)

Protection of the Stormwater System, Natural Water Bodies, and Any Potentially Sensitive Areas from Erosion

(1)

The developers shall be responsible for protection of all potentially sensitive areas adjacent to or included within construction sites. These include but are not limited to wetlands, protected uplands, water bodies, drainage structures and watersheds. These areas must be protected against sedimentation or stormwater that would be considered detrimental per local, state and federal regulations. It is the developer's responsibility to obtain the National Pollutant Discharge Elimination System (NPDES) permit for all construction sites one (1) acre and larger. The developer shall adhere to all NPDES stormwater discharge permit conditions, and any local, state and federal regulations. The most stringent rules shall apply.

(2)

Erosion control measures shall be established prior to site clearing, trenching or grading activities. Proposed stormwater facilities shall be rough excavated and graded prior to the start of site grading activities. Site runoff shall be directed to the ponds to minimize runoff to off-site areas. Failure to complete these steps at the start of site grading can result in a stop work order of all other activities until completed. Maintenance of vegetation, erosion, and sediment pollution controls, stormwater management practices and other protective measure shall occur so they will remain in good and effective operating condition at all times. Any damaged or missing sediment/erosion control measures shall be repaired and reinstalled and any sediment build-up shall be removed.

(3)

There are three (3) basic categories of practices for controlling the runoff sediment from construction sites:

(a)

Stabilization Practices to Expose the Smallest Practical Area of Land for the Shortest Possible Time. Erosion control shall plan for interim and permanent stabilization practices, including site-specific scheduling of the implementation of the practices. Site plans shall ensure that existing vegetation is preserved where attainable and that disturbed portions of the site are stabilized. Stabilization practices may include: temporary seeding, permanent seeding, mulching, geotextiles, sod stabilization, vegetative buffer strips, protection of trees, preservation of mature vegetation, and other appropriate measures. Stabilization measures shall be initiated as soon as practicable but in no case more than seven (7) days, in portions of the site where construction activities have temporarily or permanently ceased.

(b)

Runoff Control Measures. The control of surface water runoff is imperative if erosion is to be reduced. Runoff velocities must be kept low and water not allowed to concentrate, otherwise gully erosion can cause severe problems, particularly on slopes and fill areas. Slope lengths can be broken up by contour benching and furrowing, selective grading and roughening of slopes and through the use of berms, diversions and ditches. These practices not only reduce the concentration and velocity of runoff but serve to divert the water to stabilized areas such as buffer strips or sediment traps. Concentrated water flow must be controlled near hydrologically sensitive fill areas to prevent gully erosions. Down-drains, grade stabilization structures, paved ditches, jute netting or mulches with a chemical binder are essential on fill areas or steep grades that have concentrated amounts of runoff flow over them.

(c)

Sediment Trapping Measures. Structural sediment trapping measures comprise the final category of erosion protection. Since some erosion will occur even with the best use of preventive measures, sediment traps act as a final line of defense by stopping the sediment from entering water courses. Silt fences are one (1) of the most common forms of trapping sediment and they are very effective when properly planned, installed and maintained. Diversion berms are used to direct sediment-laden water to sediment traps, such as excavated pits or sediment basins. Off-stream sediment basins may be the most effective practice that can be implemented. Sediment basins do not always have to be constructed embankments in low areas. Excavation traps (holes in the ground) are less expensive, more efficient and more reliable than impounded sediment basins. Excavated traps in a series are more effective than one (1) large basin. Sediment basins retain runoff long enough to allow sediment to settle out before the water is discharged to a waterway. Periodic maintenance of basins to remove accumulated sediment is essential to maintain proper functioning and efficiency.

(4)

The contractor shall conduct continual inspections of the site and shall conduct formal inspections on the site every seven (7) days and within twenty-four (24) hours of a rainfall event of one-half (0.50) inches or more on the site. Formal inspections shall be documented and include the following: inspection date, time, and compliance issues that need to be implemented or remedied. Install additional erosion control measures if inspection reveals additional sedimentation control is necessary. Copies of all inspection records are to be maintained on-site and easily accessible for reference or review.

(5)

Any violation of local, state or federal permitting requirements and/or uncontrolled erosion, turbidity or other environmental permit violations not corrected within twenty-four (24) hours of observation shall be grounds for a stop work order on all activities not related to correction of occurrences. Violations not corrected within twenty-four (24) hours shall be subject to daily fines per the City's Code of Ordinances until the corrective measures are enacted. After seven (7) calendar days, the City reserves the right to initiate any corrective actions the City deems necessary and assess back charges to the contractor.

(C)

Construction Practices All construction activities shall conform to the following requirements:

(1)

Temporary erosion and sediment control measures shall be coordinated with permanent measures to assure economical, effective and continuous control throughout the construction phase. Temporary measures shall not be constructed for expediency in lieu of permanent measures.

(2)

Construction materials such as falsework, piling, dikes or other obstructions in watercourses should be removed as soon as practicable after completion of the operation.

(3)

Construction operations in rivers, streams, lakes and other bodies of water should be restricted to:

(a)

Areas where channel changes are shown on the plans.

(b)

Areas which must be entered to construct structures or erosion and sediment control measures, and

(c)

Areas where waters must be forded occasionally during construction, as approved by the City. Frequent fording should not be permitted: temporary bridges or other structures should be constructed where frequent crossings are necessary.

(4)

Material from sediment traps shall not be stockpiled or disposed of in a manner which makes them readily susceptible to being washed into any watercourse by runoff or high water.

(5)

Proposed well point, sump dewatering, hydrant testing and similar activities resulting in pressure discharge shall be required to adequately demonstrate that a pollution problem is not being created and that all necessary pollution control designs are clearly shown on the plans to direct construction crews during actual construction.