SUBJECT:
Title
Orange Lake Overlook Restoration - Waiver Request to Major Site Plan in Review
19865 N Us Hwy 441 Micanopy
Project #2025030052 #32721 Parcel #02709-000-00
JB Pro
LDC 6.13.2.A (1-3) - Minimum requirements
CODE states A. Plan sheets shall minimally show: (1) All pre-development and post-development basins that contribute runoff to the area proposed for development, including all off-site contributions, and areas that may be impacted by the development fully delineated and quantified. (2) The time of concentration, and travel path, for each watershed. (3) The location and design parameters for all retention/detention areas including: (a) Dimensions or coordinates for constructability. (b) Cross sections, to scale, along the width and length of each pond, showing the design high water elevation, estimated seasonal high water elevation, pond top elevation, pond bottom elevation, side slope steepness, maintenance berm width, sod stabilization of the pond side slopes, and appropriate vegetative cover on the pond bottom. A typical cross section can be used instead when sufficient information is shown on the plan view which minimally includes pond width and length call outs as measured at the pond's top and bottom elevations. (c) Soil boring location with labels.
APPLICANT requests a waiver due to the proposed site plan is under the threshold required for stormwater.
LDC 6.13.2.C - Minimum requirements
CODE states C. Geotechnical investigation report shall minimally include: (1) A summary of all subsurface exploration data and subsurface soil profiles. (2) Exploration logs, laboratory or in situ test results, groundwater information, the interpretation and analysis of the subsurface data. (3) Recommendations for design, discussion of conditions for solution of anticipated problems, and recommended geotechnical special provisions.
APPLICANT requests a waiver due to the proposed site plan is under the threshold required for stormwater.
LDC 6.13.3 - Types of stormwater management facilities
CODE states A. Existing public. (1) An adjacent public retention/detention area may be utilized for disposal of runoff generated by an applicant's improvements if it can be proven that capacity is sufficient. (2) A Stormwater Connection Application is required for any connection to or expansion of a County retention/detention area, including but not limiting to drainage retention/detention areas or conveyance systems, not previously designed or permitted to consider the applicant's improvements. (3) If the retention/detention area is still under a maintenance agreement, approval in writing must be received from the maintenance entity, when not the County, stating no objection to the use of the facility. B. Natural. (1) A natural facility may be used without further excavation upon the applicant's submittal of calculations demonstrating the existing capacity is sufficient. (2) Proof of control, ownership or easement for operation and maintenance of the natural facility shall be provided. (3) Runoff from adjacent property, to a natural facility, must be perpetuated to the extent of protecting upland owner interest. C. Proposed public. (1) Retention/detention areas shall have side slopes no steeper than 4:1 (horizontal: vertical) with a minimum berm width of 12 feet stabilized at six percent grade maximum around the entire perimeter of the facility. Side slopes steeper than 4:1 may be allowed with additional accommodations related to public safety, maintenance, and access upon approval by the County Engineer or his designee. (2) Stormwater management systems servicing a public development shall be owned and maintained by Marion County. They may be privately owned and maintained, upon approval by the County Engineer and granting of an easement to Marion County, minimally allowing but not obligating, emergency maintenance, as well as access to, drainage of, conveyance of, and storage of stormwater. (3) If fencing is used, it shall be per the County Fence Detail found in Section 7.3.1 <https://library.municode.com/fl/marion_county/codes/land_development_code?nodeId=LADECO_ART7COSPDEDE_DIV3DEDE_S7.3.1TRST> Transportation and Stormwater details. (4) The bottom of all dry water retention areas shall have appropriate vegetative cover. (5) A retention/detention area that is adjacent to a public right-of-way shall be constructed to be aesthetically pleasing with curvilinear form and shall be landscaped with a mixed plant pallet meeting Marion-friendly landscaping standards minimally consisting of four shade trees and 200 square feet of landscaping comprised of shrubs and/or groundcover for every 100 lineal feet of frontage or fractional part thereof, or, in the case of a wet facility, a littoral zone meeting the governing water management district criteria. The proposed landscaping shall be arranged to provide ease of maintenance and screening of stormwater structures. D. Proposed private. (1) Residential subdivisions. Retention/detention areas shall have side slopes no steeper than 4:1 (horizontal: vertical) with a minimum berm width of 12 feet stabilized at six percent grade maximum around the entire perimeter of the facility. Side slopes steeper than 4:1 may be allowed with additional accommodations related to public safety, maintenance, and access upon approval by the County Engineer or his designee. (2) Commercial lots or subdivisions. Retention/detention areas shall be designed with a minimum berm width of 5 feet stabilized at six percent grade maximum around the entire perimeter of the facility and side slopes: (a) No steeper than 4:1 (horizontal: vertical); or (b) Steeper than 4:1 with an access path provided to the bottom of the facility at a slope of no steeper than 3:1; or (c) As vertical walls with a structural detail for the wall design provided, adhering to Florida Building Code, an access path provided to the bottom of the facility at a slope of no steeper than 3:1, and an appropriate barrier provided when adjacent to vehicular paths and parking areas. (3) The bottom of all dry water retention areas shall have appropriate vegetative cover. (4) A retention/detention area that is adjacent to a public right-of-way shall be constructed to be aesthetically pleasing with curvilinear form and shall be landscaped with a mixed plant pallet meeting Marion-friendly landscaping standards minimally consisting of four shade trees and 200 square feet of landscaping comprised of shrubs and/or groundcover for every 100 lineal feet of frontage or fractional part thereof, or, in the case of a wet facility, a littoral zone meeting the governing water management district criteria. The proposed landscaping shall be arranged to provide ease of maintenance and screening of stormwater structures.
APPLICANT requests a waiver due to the proposed site plan is under the threshold required for stormwater.
LDC 6.13.7 - Geotechnical criteria
CODE states A. Methodology. The pattern and type of test borings shall be determined by the project engineer, geotechnical engineer, or geologist based on the project size, type, and complexity. (1) Infiltration/permeability rate tests shall follow methods acceptable to the governing State agency and shall be performed at the depth and location which will provide representative test results for use in the design of the retention/detention area. Soil identifications shall refer to the AASHTO Soil Classification System conforming to AASHTO Designation M 145-91. (2) Where visual reconnaissance, available published data, and/or initial borings suggest high karst sensitivity or lithologic variability, additional borings may be required if deemed necessary by the County Engineer or his designee. B. Minimum requirements. (1) Depth. Soil test borings shall be performed to a minimum depth of 10 feet below the proposed finished grade of the bottom of all retention/detention areas or the permanent pool elevation and once the data has been obtained the hole shall be backfilled and compacted. (2) Number of tests. At least two tests shall be performed within the boundary of each proposed retention/detention area. For each half acre of pond bottom area and for each lineal retention/detention area of 250 feet, an additional test shall be conducted. The County Engineer or his designee, may require additional tests if the initial tests indicate the need for them. (3) Infiltration/permeability tests. For retention/detention areas utilizing percolation or infiltration in the design model, there shall be a minimum of two infiltration rate tests for each retention/detention area. Data used for soil permeability testing or infiltration analyses for the retention/detention areas shall be signed and sealed by a professional engineer or professional geologist for both data and procedural accuracy. (4) Aquifer parameters. The estimated seasonal high ground water elevation and confining layer shall be clearly identified. C. Design considerations. (1) The estimated seasonal high water elevation and the confining layer shall be set no lower than the bottom of the boring for the purposes of stormwater system modeling. (2) The pond bottom elevation of a stormwater facility shall be designed a minimum of 1 foot above the estimated seasonal high water elevation. When the pond bottom is within 1 foot of the estimated seasonal high water elevation, a 50 percent reduction factor shall be used for percolation or ground water mounding analysis shall be included.
APPLICANT requests a waiver due to the proposed site plan is under the threshold required for stormwater.
LDC 6.13.8 - Stormwater conveyance criteria
CODE states A. Methodology. Calculations for stormwater collection and transmission systems shall be designed using the Rational Method based on FDOT Zone 7 Intensity - Duration Curves. Ditch and storm drain flow capacity shall be determined from Manning's Formula with coefficients of roughness based on an assumption of conditions of ultimate development. B. Minimum requirements. (1) Design storm. Conveyance systems shall be sized to accommodate the 25-year 24-hour storm event based on the condition of ultimate development. (2) Tailwater. (a) The tailwater elevation utilized shall be based on the tailwater elevation of the receiving water body plus 6 inches at the peak discharge time of the design storm. (b) Alternatively, the tailwater elevation utilized can be the design high water elevation of the 25-year 24-hour design storm. (c) Note that future connections must be able to demonstrate that conveyance can be achieved at all connections, future and existing, meeting one of the above criteria. (3) Lane spread. Lane spread shall be calculated using FDOT criteria considering the 4-inch per hour or 10-year frequency storm as appropriate, to produce the following results: (a) Subdivision Local and Minor Local Roads. The allowable lane spread shall be no greater than the crown (or high side) of the road. For all divided roadways the allowable lane spread shall be no greater than the inside (or high side) edge of pavement. (b) Arterial, Collector, and Major Local Roads. The allowable lane spread shall leave 8 feet of travel lane dry in each direction. (4) Drainage rights-of-way. All retention/detention areas within subdivision developments shall have direct access to a right-of-way. A drainage right-of-way may be necessary to establish this access. A minimum 12-foot wide, stabilized vehicle access at six percent maximum grade shall be provided to allow for ingress and egress of the retention/detention area. Drainage rights-of-way shall be a minimum of 30 feet in width. As an alternative to right-of-way, access may be provided by an easement of the same width. (5) Drainage easements. All drainage swales to facilities or underground stormwater conveyance systems shall be within drainage easements, except where rights-of-way are provided. Drainage easements shall be a minimum of 20 feet in width. (6) Floodways. If in a floodway or flood prone area, the cross drain shall be sized to accommodate the design intent of that basin. (7) Sizes. Stormwater conveyance pipes and cross culverts shall be a minimum of 18 inches diameter or equivalent. Driveway culverts shall be a minimum of 15 inches diameter or equivalent for residential use and a minimum of 18 inches diameter or equivalent for commercial use. Roof drains, prior to connection to the overall stormwater system, are exempt from minimum diameter requirements. C. Design considerations. (1) Culvert flow capacity shall be determined for the conditions of inlet control or outlet control as applicable. (2) Stormwater collection and transmission systems shall be by inlets, swales, culverts, etc. The use of siphons, pumps, or similar devices is not allowed. (3) Ditch blocks shall be designed and constructed with hard core centers. (4) Stormwater flow velocity shall be taken into consideration in the design of all drainage ditches and appropriate erosion protection shall be provided in accordance with the FDOT Drainage Manual. (5) Where any storm pipe terminates at an earthen slope a mitered end section and concrete collar, or approved equal, is required. Concrete mitered end sections are required for culverts, cross drains and side drains when within a County right-of-way with posted speeds of 40 mph or greater.
APPLICANT requests a waiver due to the proposed site plan is under the threshold required for stormwater.
LDC 6.13.12 - Operation and maintenance
CODE states A. The stormwater management system and associated elements shall be operated and maintained in accordance with this Code, the applicable water management district, the manufacturer's specifications, and other specifications necessitated by the design. B. An operation and maintenance document shall be provided. The owner shall include a signed and dated certification in the document as follows: I hereby certify that I, my successors, and assigns shall perpetually operate and maintain the stormwater management and associated elements in accordance with the specifications shown herein and on the approved plan (this signature is not required until the final submittal). C. Operation and maintenance documentation shall be incorporated into any contracts, covenants, and/or restrictions for the property owner association and/or property management association.
APPLICANT requests a waiver due to the proposed site plan is under the threshold required for stormwater.
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