To ensure attainment of the objectives of this subchapter and that performance standards will be met, the design, construction, and maintenance of drainage systems shall be consistent with the following standards:
(A) Channeling stormwater runoff directly into water bodies shall be prohibited. Instead, runoff should be routed over a longer distance, through swales and other works designed to increase infiltration, allow suspended solids to settle, and remove pollutants;
(B) Natural watercourses shall not be dredged, cleared of vegetation, deepened, widened, straightened, stabilized or otherwise altered. Water shall be retained or detained before it enters any natural watercourse in order to preserve the natural hydrodynamics of the watercourse and to prevent siltation or other pollution;
(C) The area of land disturbed by development shall be as small as practicable. Those areas which are not to be disturbed shall be protected by an adequate barrier from construction activity. Whenever possible, natural vegetation shall be retained and protected;
(D) No grading, cutting or filling shall be commenced until erosion and sedimentation control structures have been installed between the disturbed area and water bodies, watercourses and wetlands;
(E) Land which has been cleared for development and upon which construction has not commenced shall be protected from erosion by appropriate techniques designed to revegetate the area;
(F) Sediment shall be retained on the site of the development;
(G) Wetlands and other water bodies shall not be used as primary sediment traps during development;
(H) Erosion and sedimentation facilities shall receive regular maintenance to ensure that they continue to function properly;
(I) Artificial watercourses shall be designed, considering soil type, so that the velocity of flow is low enough to prevent erosion;
(J) City and MTWCD maintained facilities are subject to the level of service and standards the city and MTWCD respectively have the ability to provide.
(K) Vegetated buffer strips shall be created or, where practicable, retained in their natural state along the banks of all watercourses, water bodies or wetlands. The width of the buffer shall be sufficient to prevent erosion, trap the sediment in overland runoff, provide access to the water body and allow for periodic flooding without damage to structures;
(L) Intermittent watercourses, such as swales, shall be vegetated;
(M) Retention and detention ponds shall be used to retain and detain the increased and accelerated runoff which the development generates. Water shall be released from detention ponds into watercourses or wetlands at a rate and in a manner approximating the natural flow which would have occurred before development;
(N) Although the use of wetlands for storing and purifying water is encouraged, care must be taken not to overload their capacity, thereby harming the wetlands and transitional vegetation;
(O) Dry retention facilities, a volume sufficient to retain the runoff from one-half (½) inch of rainfall of entire site (or one and one-half (1½) inches of runoff of impervious surfaces if greater) shall be provided;
(P) Wet detention facilities, no more than one-half (½) of this volume may be discharged in the first seventy-two (72) hours following a storm event; the total volume recovery occurring in fourteen (14) days;
(Q) Volume in the permanent pool (below maintained water level) in wet detention facilities must be sufficient to provide a residence time of at least fourteen (14) days. This volume may be determined as one and one-half (1½) inches over the impervious portion of the drainage basin, plus one-half (½) inch over the pervious portion of the basis;
(R) The inlet structure and outlet structure in wet detention facilities shall be located that contact between stormwater and littoral plantings is maximized. The inlet to the wet detention pond should be baffled to reduce turbulence, and the outlet from the wet detention pond shall be located as far as practicable from the inlet and should be constructed with skimmers to prevent the transmission of oils, grease and floating debris;
(S) Runoff from parking lots shall be treated to remove oil and sediment before it enters receiving waters;
(T) Detention and retention areas shall be designed when possible so that shorelines are sinuous rather than straight and so that the length of shoreline is increased, thus offering more space for the growth of littoral vegetation;
(U) The use of drainage facilities and vegetated buffer zones as open space, recreation and conservation areas shall be encouraged;
(V) Disturbed areas shall be stabilized and protected from erosion as soon as possible.
(W) Retention areas shall be designed as dry- bottom ponds, with the seasonal high groundwater table demonstrated to be at least one (1) foot below the finished pond bottom. Wet bottom ponds may be used provided that the entity responsible for maintenance shall not be the city.
(X) Detention reservoirs may be designed as wet-bottom or dry-bottom ponds. If designed as dry- bottom ponds, the seasonal high groundwater table shall be demonstrated to be at least one (1) foot below the finished pond bottom. If designed as a wet- bottomed pond, the depth shall be sufficient to limit growth of emergent plants to designated peripheral littoral zones, if applicable. Detention ponds shall be designed to remain hydraulically separate from the retention ponds so that backflow and mixing does not occur.
(Y) Dry retention systems shall be designed to recover one-half (½) of their volume in twenty-four (24) hours and the entire volume in seventy-two (72) hours. Wet detention systems shall recover their volumes in less than fourteen (14) days.
(Z) The City Engineer may, under certain extenuating circumstances, when there is no other alternative, waive the pond system requirement for wet detention systems.
(AA) A developer may elect to implement voluntary low impact development design standards for new development or redevelopment in accordance with this section.
(1) Voluntary Low Impact Development (LID) is the voluntary implementation of designs and standards that further reduce stormwater pollution by maximizing open, green, and pervious space during development or redevelopment of a site. It is the developer's responsibility to comply with the requirements for stormwater management contained within Chapter 174 of the Palm Bay Code of Ordinances.
(2) The City Engineer, or designee, shall review and concur that the low impact development designs and standards are consistent with the City's Low Impact Development Manual.
(3) Voluntary LID designs and standards shall, at a minimum, be planned and designed to manage and capture stormwater runoff, to the maximum extent feasible, in a manner consistent with the integrated management practices (IMPs) as outlined in the City's Low Impact Development Manual.
(4) The developer shall adhere to the LID designs and standards as contained in the City's Low Impact Development Manual to be entitled to a density or intensity bonus, more floor space than allowed under the current or proposed future land use designation or zoning, greater height, a reduction in fees, credits, or granting of other incentives as authorized by City Council.
(Ord. 95-33, passed 8-24-95; Am. Ord. 2010-87, passed 1-6-11; Am. Ord. 2022-86, passed 8-18-22) Penalty, see §
174.079