§ 33-16. Excavations; public hearing required; exceptions.
(a)
Public hearing required for certain excavations; exception. No excavations below the level of any street, highway or right-of-way shall be made except upon approval after public hearing; provided, no public hearing is required for excavations for the following purposes:
(1)
The foundation of a building or any structure to be constructed immediately after such excavations. All excavations shall be refilled after construction of such foundation in a manner which will prevent accumulation of stagnant water or other hazard.
(2)
Swimming pools.
(3)
Water hazard in a bona fide golf course.
(4)
Canals which are part of Miami-Dade County or South Florida Water Management District canal system.
(5)
Reflecting ponds and water features with a maximum depth of six (6) feet of water so long as said amenities are completely lined with impervious material, a horizontal five-foot safety shelf is provided around the perimeter of the reflecting pond or water feature at an elevation where not more than eighteen (18) inches of water is provided on the shelf area and so long as backsloping or a perimeter berm is provided to prevent overland storm water runoff from entering the water body.
(6)
Lake excavations west of the salt barrier line shall also be allowed without a public hearing in all districts within the developable boundaries of the adopted metropolitan development pattern map of the Comprehensive Development Master Plan as may be amended from time to time. Public hearings will be required in all areas east of the salt barrier line. Applicants may choose to go to public hearing for lake excavation approval even if same is not required; provided, however, that if an unusual use is requested, applicants shall proceed in accordance with Section 33-13. In order to receive a waiver from the public hearing requirement, applicants must submit complete excavation plans to the Department. The Department shall review lake excavation plans for compliance with the requirements noted below. All plans shall be reviewed and approved or denied by the Department within fifteen (15) days from the date of submission. Applicants shall have the right to extend the fifteen-day period upon timely request made in writing to the Department. Staff shall have the right to extend the fifteen-day period by written notice to the applicant that additional information is needed to process the plan. Denials shall be in writing and shall specifically set forth the grounds for denial. If the plan is disapproved by the Department on the grounds of requirement (6)b, (6)j, (6)l, or (6)r below, the applicant may appeal to the Community Zoning Appeals Board in accordance with procedure established for appeals of administrative decision in Section 33-311(c). Disapprovals on all other grounds listed below may be appealed to the Community Zoning Appeals Board as unusual use requests in accordance with procedure established in Section 33-13.
In order to waive the public hearing requirement for a lake excavation, the excavation must be designed and excavated in accordance with the following conditions and requirements:
a.
Final plans shall be substantially in compliance with those submitted and approved for the administrative site plan review for the proposed lake excavation. The grading, leveling, sloping of the banks and perimeter restoration shall be on a progressive basis as the project develops and the excavation progresses. In accordance with this requirement, the applicant will submit final as-built surveys prepared and sealed by a Florida-licensed surveyor and/or professional engineer upon completion of the excavation, or upon request of either the Director or the Director of Environmental Resources Management when it appears that the excavation is proceeding contrary to approved plans. The property shall be staked and posted to meet with the approval of the Director and the Director of Environmental Resources Management; said stakes shall be maintained in proper position so that the limits of excavation, slopes and grade levels may be easily determined and posts shall warn the public concerning possible hazards. Upon completion of the project, the property shall be restored and left in an acceptable condition meeting the approval of the Director of Environmental Resources Management and the Director.
b.
If in the opinion of the Director the excavation is hazardous to the surrounding area, the hazardous area will be fenced in, or otherwise protected, by the applicant as directed by the Director.
c.
During the entire operation explosives shall not be used.
d.
The applicant shall be permitted to operate between the hours of 7:00 a.m. and 5:00 p.m. on weekdays; Saturday and Sunday operation and/or other hours of operation than 7:00 a.m. to 5:00 p.m., may be permitted by the Director only if the same does not become objectionable, in his opinion, to the surrounding area.
e.
The time for the completion of the project including excavation, grading, etc., shall be determined by the Director and the work shall be carried on continuously and expeditiously so that the excavation will be completed within the allocated time.
f.
If the operation is discontinued, abandoned, falls behind schedule, or time expires, the existing excavation shall immediately be sloped to conform to the approved slope.
g.
In order to insure compliance with all terms and conditions imposed, a cash or surety bond or substantially equivalent instrument meeting with the approval of the Director shall be posted with the Department, payable to Miami-Dade County, in an amount as may be determined and established by the Director. Said instrument shall be in such form that the same may be recorded in the public records of Miami-Dade County and said instrument shall be executed by the property owner and any and all parties who may have an interest in the land, such as mortgagees, etc. The bond amount will be based on the volume of cut required to create the approved slope configuration.
h.
The title of the property in question shall not be transferred without the approval of the Director unless the excavation of the subject property has been completed and/or unless the bond has been released.
i.
The excavation use permit shall be renewable annually by the Department. Permits will be canceled only when the work is found to be in violation of any of the conditions or requirements of this section and/or when it is detrimental and/or incompatible with the surrounding neighborhood.
j.
Prior to administrative site plan review, a report on soil borings taken on-site shall be submitted for review to the Department of Environmental Resources Management to determine if excavation to the requested depth may result in the displacement of layers of soft material (e.g., sand) and cause sinking of nearby properties. In addition, if hard rock is not encountered during excavation, the Department of Environmental Resources Management may require the vertical cut to be modified in such a manner that a stable side slope will be sustained.
k.
The depth of the lake excavation shall not be less than ten (10) feet below mean low water elevation (W.C.2.4). The maximum depth of the excavation shall be limited to that depth computed to contain water of two hundred fifty (250) ppm chlorides as projected to the year 2000. Penetration of the aquiclude, as determined by the Director of the Department of Environmental Resources Management, is prohibited.
l.
An earth berm, or alternative structure as approved by the Director of the Department of Environmental Resources Management, shall be constructed around the perimeter of all lakes to prevent overland storm water runoff from entering the lake. The berm shall be constructed adjacent to the lake top of slope on the landward side. Said berm shall extend one (1) foot above the D.C.F.C. elevation. The landward slope of the berm shall have a gradient not steeper than one (1) foot vertical to four (4) feet horizontal. The lakeward slope shall not be steeper than the required lake slope. Berming and backsloping treatments shall be constructed in a manner acceptable to the Director of the Department of Environmental Resources Management.
m.
The maximum permissible slope shall be in one (1) of the following manners:
1.
Lakes adjacent to arterial roadways (slope option available in every case): Beginning at top of slope (D.C.F.C. elevation), a slope dropping one (1) foot vertical to seven (7) feet horizontal extending lakeward to a point where five (5) feet of water depth is provided below the mean low water elevation (W.C.2.4.); thence begin deep cut with a slope as material permits (Note: A twenty-foot minimum offset, measured from lake top of slope to the zoned right-of-way per Section 33-133, shall be provided when the lake is adjacent to an arterial roadway. The offset and berm (see Section 33-16(a)(6)(l)) may be deleted where curb and gutter roadway is provided. Where the water area lies outside of a horizontal roadway curve, the necessary shoulder safety requirements shall be provided in accordance with the requirements of the public works manual). Drainage structures, other than approved outfall pipes, are not permitted within the lake slope area.
2.
Lake(s) adjacent to roadways other than arterial roadways:
(a)
Option 1., above, or
(b)
Beginning at top of slope (D.C.F.C. elevation), a slope dropping one (1) foot vertical to four (4) feet horizontal shall be provided extending lakeward to a point where three (3) feet of water depth is provided below the mean low water elevation (W.C.2.4.), followed by an eight-foot horizontal shelf; thence begin a deep cut with a slope as material permits. (Note: Berm (see Section 33-16(a)(6)(l)) may be deleted where a curb and gutter roadway is provided. Where the water area lies outside of a horizontal roadway curve, the necessary shoulder safety requirements shall be provided in accordance with the requirements of the public works manual).
3.
Lake(s) with common or public access to the lake shore and not adjacent to roadways:
(a)
Options 1., and 2., above, or
(b)
Beginning at top of slope (D.C.F.C. elevation), a slope dropping one (1) foot vertical to three (3) feet horizontal with slope protection as required by the Director of the Department of Environmental Resources Management shall be provided extending lakeward to a point where three (3) feet of water depth is provided below the mean low water elevation (W.C.2.4.) followed by a five-foot horizontal shelf; thence, begin a deep cut with a slope as material permits.
4.
Lake(s) without common or public access to the lake shore and not adjacent to roadways:
(a)
Options 1, 2, and 3, above, or
(b)
Beginning at top of slope (D.C.F.C. elevation), a slope dropping one (1) foot vertical to one (1) foot horizontal with slope protection as required by the Director of the Department of Environmental Resources Management shall be provided extending lakeward to a point where three (3) feet of water depth is provided below the mean low water elevation (W.C.2.4.) followed by a five-foot horizontal shelf; thence, begin a deep cut with a slope as material permits.
n.
No positive drainage of storm water from roads or any other source will be allowed to enter the excavation except as the result of issuance of a class II permit by the Department of Environmental Resources Management. Retention of pollutants is one (1) criterion for issuance of a class II permit.
o.
There shall be no direct connection between a lake excavation and a drainage canal. A system to permit overflows from lakes to canals for flood control purposes is allowable.
p.
No portion of the proposed lake excavation area shall fall within the thirty-day cone of influence of any public water supply wellfield as defined in Section 24-12.1. Between the thirty- and two-hundred-ten-day cones of influence of any public water supply wellfield, lake excavations will be permitted to a maximum water depth of forty (40) feet below mean low water elevation (W.C.2.4.).
q.
That the dedication of rights-of-way shall be made in accordance with Section 33-133 of the Code of Miami-Dade County unless the Director of Public Works deems such are not necessary or requires a lesser amount. Improvements shall be made to such rights-of-way in order to comply with and in accordance with the requirements of the manual of public works construction, as may be deemed lacking, desirable and necessary by the Public Works Director.
A public hearing shall not be waived for any excavation requiring a class I or class IV standard form permit pursuant to Section 24-58.1(1)(a), (c) and (d) and for short form class I or class IV permits for which a public hearing has been requested pursuant to Section 24-58.2(I)(B).
r.
In all zoning districts that have open space requirements, development plans submitted for review and approval which contain a lake(s) shall have at least thirty (30) percent of the dry land open space requirements satisfied on land immediately adjacent to the lake(s) perimeter. In districts with no open space requirements, roads, parks or other open areas servicing the development shall be placed adjacent to the lake(s) in a manner that provides aesthetic benefits to the development.
(b)
Definitions. For the purposes of this section, D.C.F.C. shall be defined as Miami-Dade County flood control elevation. W.C.2.4 shall be defined as "water control" page 2.4 in the public works manual of Miami-Dade County, which includes a detailed drawing of the mean low water elevation points throughout Miami-Dade County.
(c)
Notwithstanding any other provision of this section to the contrary, where an excavation is made outside of the Urban Development Boundary in a zoning district authorizing residential uses, the use of fill or aggregate material shall comply with Section 33-13(e)(vi).
(Ord. No. 57-19, § 5(L), 10-22-57; Ord. No. 62-22, § 1, 5-15-62; Ord. No. 66-43, § 1, 9-20-66; Ord. No. 83-4, §§ 1, 2, 2-1-83; Ord. No. 83-70, § 15, 9-6-83; Ord. No. 95-215, § 1, 12-5-95; Ord. No. 96-127, § 5, 9-4-96; Ord. No. 97-27, § 1, 4-8-97; Ord. No. 17-7, § 2, 1-24-17)